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WO2023175893A1 - Drive device and air conditioning device - Google Patents

Drive device and air conditioning device Download PDF

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Publication number
WO2023175893A1
WO2023175893A1 PCT/JP2022/012596 JP2022012596W WO2023175893A1 WO 2023175893 A1 WO2023175893 A1 WO 2023175893A1 JP 2022012596 W JP2022012596 W JP 2022012596W WO 2023175893 A1 WO2023175893 A1 WO 2023175893A1
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WO
WIPO (PCT)
Prior art keywords
connection
switching
magnetic flux
electric motor
value
Prior art date
Application number
PCT/JP2022/012596
Other languages
French (fr)
Japanese (ja)
Inventor
央 大城
貴彦 小林
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2024507396A priority Critical patent/JPWO2023175893A1/ja
Priority to PCT/JP2022/012596 priority patent/WO2023175893A1/en
Publication of WO2023175893A1 publication Critical patent/WO2023175893A1/en

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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02PCONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P25/00Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
    • H02P25/16Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring
    • H02P25/18Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring with arrangements for switching the windings, e.g. with mechanical switches or relays

Definitions

  • the present disclosure relates to a drive device that uses an inverter to drive an electric motor whose wiring state can be switched, and an air conditioner that includes the drive device.
  • Patent Document 1 discloses a method of estimating magnetic flux information including induced voltage and secondary magnetic flux using an adaptive observation device.
  • the success or failure of the wiring connection is determined by comparing values corresponding to the induced voltage constants before and after the wiring connection switching. If the compressor motor is a permanent magnet type motor and the motor is demagnetized, the problem with conventional technology is that it is difficult to determine whether to switch because the induced voltage constant is smaller than the expected value.
  • the present disclosure has been made in view of the above, and an object of the present disclosure is to provide a drive device that can appropriately determine the success or failure of wire connection switching, regardless of the demagnetization level of the electric motor.
  • a drive device includes a converter that rectifies an AC voltage supplied from an AC power source, and a set rotation speed that corresponds to a set rotation speed from the rectified voltage obtained by the converter.
  • An inverter that generates an alternating current voltage and supplies it to the motor, a connection switching device that switches the connection state of the motor windings according to a switching command, a detection unit that detects the load current of the motor, and controls the inverter and the connection switching device. It has a control section.
  • the control unit estimates the secondary magnetic flux before switching, and calculates the estimated value of the secondary magnetic flux before switching and the preset induction in the state of the first connection.
  • the demagnetization level is determined by comparing it with the voltage constant, and after switching to the second connection is performed by the connection switching device, the secondary magnetic flux after switching is estimated, and the secondary magnetic flux after switching is estimated.
  • the success or failure of connection switching is determined by comparing the value with a value obtained by correcting a preset induced voltage constant in the second connection state based on the demagnetization level.
  • the drive device has the effect that it is possible to appropriately determine the success or failure of wire connection switching, regardless of the demagnetization level of the electric motor.
  • a diagram showing the configuration of a drive device according to Embodiment 1 A diagram showing details of the stator winding and connection switching device of the electric motor according to Embodiment 1.
  • Wiring diagram showing details of a switching device of a wiring switching device included in the drive device according to Embodiment 1 A diagram conceptually showing the connection state of the stator windings when the motor is Y-connected.
  • a diagram for explaining a control sequence when switching connections in Embodiment 1 A diagram showing the configuration of an air conditioner according to Embodiment 2
  • FIG. 1 is a diagram showing the configuration of a drive device 100 according to the first embodiment.
  • the drive device 100 is a device that drives the electric motor 1 connected to the load 5, and includes a converter 3, an inverter 4, a connection switching device 20, and a control section 30. Also shown in FIG. 1 are a motor 1, an AC power source 2, and a load 5.
  • the converter 3 receives the AC voltage supplied from the AC power supply 2, rectifies the AC voltage, and outputs the DC voltage.
  • the DC voltage output from converter 3 may be referred to as "bus voltage.”
  • the converter 3 may be a converter that performs rectification using a diode bridge, or may be a boost converter that can increase the bus voltage using a reactor and a switching element controlled by the control unit 30. .
  • the inverter 4 is controlled by the control unit 30 and generates an AC voltage corresponding to the set rotational speed from the rectified voltage obtained by the converter 3 and supplies it to the electric motor 1. More specifically, the inverter 4 converts the DC voltage output from the converter 3 into an AC voltage whose voltage is variable and whose frequency is variable, and drives the motor 1.
  • the control unit 30 controls the inverter 4 based on the load current to the electric motor 1 that the inverter 4 outputs.
  • the drive device 100 further includes detection units 6a and 6b that detect the load current of the electric motor 1.
  • the detection units 6a and 6b may be a known current sensor such as ACCT (Alternating Current Transformer) or DCCT (Direct Current Transformer) that directly detects the load current of the motor 1 as shown in FIG.
  • the detection method or estimation method performed by the detection units 6a and 6b is not limited. Information on the load current detected by the detection units 6a and 6b is taken into the control unit 30.
  • the motor 1 is a three-phase synchronous motor, and the ends of the stator windings are drawn out to the outside of the motor 1, and the windings of the motor 1 can be Y-connected or ⁇ -connected. .
  • the Y connection is a star connection
  • the ⁇ connection is a delta connection.
  • the connection switching device 20 switches the connection state of the windings of the electric motor 1 according to a switching command. That is, the connection switching device 20 selects the connection of the electric motor 1.
  • the connection switching device 20 includes switching devices 21, 22, and 23.
  • the control unit 30 controls which connection to drive the electric motor 1, the Y connection or the ⁇ connection.
  • FIG. 2 is a diagram showing details of the stator winding and connection switching device 20 of the electric motor 1 according to the first embodiment.
  • the first ends 41a, 42a, 43a of the three-phase windings 41, 42, 43 consisting of the U-phase, V-phase, and W-phase of the electric motor 1 are connected to the outside of the drive device 100. It is connected to terminals 41c, 42c, and 43c.
  • the first end 41a is connected to the external terminal 41c of the drive device 100
  • the first end 42a is connected to the external terminal 42c of the drive device 100
  • the first end 41a is connected to the external terminal 42c of the drive device 100.
  • 43a is connected to an external terminal 43c of the drive device 100.
  • the first ends 41a, 42a, 43a are also connected to the U-phase, V-phase, and W-phase outputs of the inverter 4.
  • the second ends 41b, 42b, 43b of the three phase windings 41, 42, 43 of the electric motor 1 are connected to external terminals 41d, 42d, 43d of the drive device 100.
  • the second end 41b is connected to the external terminal 41d of the drive device 100
  • the second end 42b is connected to the external terminal 42d of the drive device 100
  • the second end 41b is connected to the external terminal 41d of the drive device 100.
  • 43b is connected to an external terminal 43d of the drive device 100.
  • the external terminals 41c, 42c, 43c, 41d, 42d, and 43d are connected to the connection switching device 20.
  • the connection switching device 20 has the switching devices 21, 22, and 23 as described above.
  • the current flowing through the winding 41 flows through the switch 21, the current flowing through the winding 42 flows through the switch 22, and the current flowing through the winding 43 flows through the switch 23.
  • the switch 21 has the function of switching the path of the current flowing through the winding 41
  • the switch 22 has the function of switching the path of the current flowing through the winding 42
  • the switch 23 has the function of switching the path of the current flowing through the winding 43. It has the function of switching the path of flowing current.
  • electromagnetic contactors whose contacts are electromagnetically opened and closed are used.
  • the electromagnetic contactor includes components called a relay and a contactor.
  • the configuration of the electromagnetic contactor is, for example, the configuration shown in FIG. The connection status will be different.
  • FIG. 3 is a wiring diagram showing details of the switches 21, 22, and 23 of the connection switching device 20 included in the drive device 100 according to the first embodiment.
  • the connection state between the excitation coils 211, 221, 231 and the power supply 25 is switched by the semiconductor switch 204 controlled by the connection selection signal Sc output from the control unit 30, and the presence or absence of current is switched. is also switched.
  • the connection selection signal Sc indicates the first value
  • the semiconductor switch 204 is turned off, no current flows through the excitation coils 211, 221, and 231, and the connection selection signal Sc indicates the second value. If so, the semiconductor switch 204 is turned on, and current flows to the excitation coils 211, 221, and 231.
  • the first value is, for example, Low, and the second value is, for example, High. If the connection selection signal Sc is output from a circuit with sufficient current capacity, the exciting coils 211, 221, 231 may be directly driven by the connection selection signal Sc without using the semiconductor switch 204.
  • the common contact 21c is connected to the external terminal 41d via a lead wire, the normally closed contact 21b is connected to the neutral node 24, and the normally open contact 21a is connected to the W phase of the inverter 4. connected to the output.
  • the common contact 22c is connected to the external terminal 42d via a lead wire, the normally closed contact 22b is connected to the neutral node 24, and the normally open contact 22a is connected to the V phase of the inverter 4. connected to the output.
  • the common contact 23c is connected to the external terminal 43d via a lead wire, the normally closed contact 23b is connected to the neutral node 24, and the normally open contact 23a is connected to the U phase of the inverter 4. connected to the output.
  • the switches 21, 22, 23 are switched to the normally open contacts 21a, 22a, 23a, contrary to the case shown in FIG. That is, the common contacts 21c, 22c, and 23c are connected to the normally open contacts 21a, 22a, and 23a.
  • the second ends 41b, 42b, 43b of the windings 41, 42, 43 are connected to the first ends 42a, 43a of the windings 43, 42, 41 via the switch 21, 22, 23. , 41a. Therefore, the connection state of the electric motor 1 is a ⁇ connection state.
  • connection selection signal Sc indicates the first value, for example Low
  • the motor 1 is in the Y connection state
  • connection selection signal Sc indicates the second value, for example High
  • the motor 1 is in the ⁇ connection state. becomes the state of
  • FIG. 4 is a diagram conceptually showing the connection state of the stator windings when the electric motor 1 is connected in a Y-connection.
  • FIG. 5 is a diagram conceptually showing the connection state of the stator windings when the electric motor 1 is connected in a ⁇ connection.
  • ⁇ aY ⁇ 3 ⁇ a ⁇ ...(3) ⁇ aY is an induced voltage constant during Y connection, and ⁇ a ⁇ is an induced voltage constant during ⁇ connection.
  • the allowable current of the motor 1 also differs between Y-connection and ⁇ -connection, and the allowable current is larger in ⁇ -connection.
  • the current value can be reduced to 1/ ⁇ 3 of the ⁇ connection.
  • the number of turns can be designed to be suitable for driving at low speeds with a Y connection, and the current value can be reduced compared to when a Y connection is used over the entire speed range. This makes it possible to increase the efficiency of driving 1. Note that low speed rotation corresponds to a small load.
  • the control unit 30 controls the inverter 4 and the connection switching device 20.
  • the control unit 30 controls the inverter 4 to change the frequency and voltage value of the output voltage from the inverter 4.
  • the control unit 30 controls the connection switching device 20 to select the connection of the electric motor 1 .
  • control unit 30 also controls the boost converter to change the bus voltage.
  • FIG. 6 is a diagram showing the configuration of the control section 30 included in the drive device 100 according to the first embodiment.
  • FIG. 6 shows all the components that the drive device 100 has, the electric motor 1, the AC power source 2, and the load 5.
  • control section 30 includes an operation command section 31 and an inverter control section 32, and, when converter 3 is a boost converter, also has a control section for controlling the boost converter.
  • the operation command unit 31 outputs a frequency command value ⁇ * , a zero selection signal Sz, and a connection selection signal Sc.
  • the frequency command value ⁇ * and the zero selection signal Sz are supplied to the inverter control section 32.
  • the frequency command value ⁇ * is set to a value suitable for the operating state.
  • the converter 3 is a boost converter
  • the bus voltage command value is set to a value suitable for the operating state, and the bus voltage is boosted to an arbitrary value.
  • the inverter control unit 32 outputs a PWM (Pulse Width Modulation) signal Sm that controls the switching operation of the inverter 4 to the inverter 4, and changes the frequency and voltage value of the output voltage of the inverter 4.
  • PWM Pulse Width Modulation
  • the connection selection signal Sc indicates a first value, for example, Low, when the Y connection is selected, and indicates a second value, for example, High, when the ⁇ connection is selected.
  • the zero selection signal Sz normally indicates a first value, eg, Low, and indicates a second value, eg, High, during the period of zero current control, which will be described later.
  • the operation command unit 31 determines whether the stator windings of the electric motor 1 are Y-connected or ⁇ -connected, determines the target rotation speed, and determines the success or failure of switching the connections, and issues a connection selection signal based on the determination.
  • Sc, frequency command value ⁇ * , and inverter stop signal So are output.
  • the inverter stop signal So normally indicates a first value, e.g., Low, when there is no abnormality in the connection state, and when it is determined that the switching has failed in the connection switching success/failure determination described later, it takes a second value, e.g. Indicates High.
  • the operation command unit 31 decides to connect the electric motor 1 to a ⁇ connection when the difference between the room temperature and the set temperature is large, and selects the connection.
  • a frequency command value ⁇ * that sets the signal Sc to a second value for example, a signal indicating High
  • sets the target rotation speed to a relatively high value and gradually increases the frequency to the frequency corresponding to the target rotation speed after startup.
  • Output When the frequency reaches the frequency corresponding to the target rotational speed, the operation command unit 31 maintains the state until the room temperature approaches the set temperature, and when the room temperature approaches the set temperature, switches the connection of the electric motor 1 to the Y connection. Therefore, the connection selection signal Sc is set to a first value, for example, a signal indicating Low, and then control is performed to maintain the room temperature close to the set temperature. This control includes frequency adjustment, stopping and restarting the electric motor 1, and the like.
  • the motor 1 is a three-phase synchronous motor
  • the induced voltage constant ⁇ a and the value of the secondary magnetic flux ⁇ dr are the same value, so the connection state is determined based on the change in the estimated value of the secondary magnetic flux ⁇ dr. be able to.
  • demagnetization or magnetization occurs due to the temperature dependence of the permanent magnet. For example, if the permanent magnets constituting the electric motor 1 are magnets that demagnetize at high temperatures, irreversible demagnetization occurs where the magnetic force does not return to its original state when the temperature exceeds a certain temperature, and the performance of the electric motor 1 is significantly reduced.
  • the induced voltage constant ⁇ a in the first connection state before switching the connection and the induced voltage constant ⁇ a in the second connection state after switching the connection are set in advance. For example, a design value when the electric motor 1 was designed may be used as the set value of the induced voltage constant ⁇ a.
  • the control unit 30 estimates the secondary magnetic flux ⁇ dr before switching the wiring connection. As a method for estimating the secondary magnetic flux ⁇ dr, as described above, Patent Document 2 discloses a method of estimating magnetic flux information including the induced voltage and the secondary magnetic flux ⁇ dr using an adaptive observation device. The control unit 30 estimates the secondary magnetic flux ⁇ dr by using a method similar to this method.
  • the control unit 30 calculates the demagnetization level based on the following equation (4) by comparing the estimated value of the secondary magnetic flux ⁇ dr and a preset induced voltage constant ⁇ a in the first connection state.
  • Demagnetization level value (%) estimated value of secondary magnetic flux ⁇ dr/induced voltage constant ⁇ a ⁇ 100 (4)
  • the control unit 30 estimates the value of the secondary magnetic flux ⁇ dr after switching the connection, and calculates the value of the induced voltage constant ⁇ a after switching the connection, that is, in the second connection state.
  • the determination is made in consideration of the demagnetization level obtained by equation (4).
  • the control unit 30 After the connection switching operation is performed, the control unit 30 re-estimates the secondary magnetic flux ⁇ dr after switching the connection, and calculates the estimated value of the secondary magnetic flux ⁇ dr and the preset value in the second connection state after switching the connection.
  • the induced voltage constant ⁇ a is compared with the induced voltage constant ⁇ a to determine the success or failure of the connection switching.
  • the judgment value K is determined, and the control unit 30 compares the correction calculation result of the following correction formula (5) with the judgment value K, and switches if the calculation result is less than the absolute value of the judgment value K. is determined to be normal. (Estimated value of secondary magnetic flux ⁇ dr) - (induced voltage constant ⁇ a x demagnetization level value (%)/100) ... (5)
  • the control unit 30 determines the judgment value K to a positive or negative value, taking into account the variation in control convergence after switching the wiring, which affects the estimated value of the secondary magnetic flux ⁇ dr in addition to the influence of demagnetization.
  • the judgment is performed with a likelihood of . More specifically, when determining the success or failure of connection switching, the control unit 30 determines whether the estimated value of the secondary magnetic flux ⁇ dr after switching and the preset induced voltage constant ⁇ a in the state of the second connection are based on the demagnetization level. When comparing the corrected value, the determination value K is given a positive or negative likelihood to determine whether the connection switching is successful or not. Thereby, the drive device 100 can prevent determining that the switching has failed even though the switching of the wire connections has been performed normally.
  • control unit 30 determines that the switching has failed in the connection switching success/failure determination, the control unit 30 deactivates the PWM signal Sm by setting the inverter stop signal So to a second value, for example, a signal indicating High, and stops the electric motor 1.
  • the control unit 30 determines that the switching state is abnormal as a result of the connection switching success/failure determination, it performs an operation to stop the electric motor 1 .
  • the operation command unit 31 changes the value of the connection selection signal Sc for switching from one of the Y connection and the ⁇ connection to the other, and also temporarily changes the value of the zero selection signal Sz during the connection switching operation. change to
  • the operation command unit 31 when switching the connection, temporarily changes the zero selection signal Sz, which normally indicates Low, to a signal which indicates High. During the period in which the zero selection signal Sz is High, the operation command unit 31 switches the connection selection signal Sc from a High signal to a Low signal, or from a Low signal to a High signal.
  • the inverter control unit 32 In order to control the inverter 4, the inverter control unit 32 generates a PWM signal Sm and supplies it to the inverter 4 based on information supplied from the detection unit that detects the load current of the electric motor 1.
  • the inverter 4 supplied with the PWM signal Sm drives the electric motor 1 by changing the output voltage value and frequency according to the PWM signal Sm.
  • FIG. 6 shows an example in which the load current of the motor 1 is estimated from information about the bus current Idc.
  • connection switching device 20 If the current flowing through the connection switching device 20 is controlled to be zero and the connection switching device 20 is made to perform a switching operation in that state, arc discharge will occur between the contacts of the switching devices 21, 22, and 23 during switching. This can be prevented. In this way, there is no need to reduce the rotational speed of the electric motor 1 to zero for switching.
  • connection switching device 20 In order to make the current flowing through the connection switching device 20 zero, there is a method of detecting the current flowing through the motor 1 and controlling the current flowing to zero by the switching operation of the inverter 4. Alternatively, there is a method of cutting off the current by stopping the switching operation of the inverter 4. Alternatively, by using both of these methods in combination, it is possible to achieve zero current flowing through the connection switching device 20.
  • FIG. 7 is a diagram for explaining a control sequence when wiring connections are switched in the first embodiment. In FIG. 7, switching from Y connection to ⁇ connection is assumed.
  • FIG. 7(A) shows the current flowing through the connection switching device 20.
  • FIG. 7(B) shows a time chart of the zero selection signal Sz.
  • FIG. 7(C) shows a time chart of the connection selection signal Sc.
  • FIG. 7(D) shows the estimated value of the secondary magnetic flux ⁇ dr and the induced voltage constant ⁇ a.
  • the control unit 30 estimates the secondary magnetic flux ⁇ dr before switching and calculates the demagnetization level of the electric motor 1. After switching the wiring connection, the time constant of the control response until the control becomes stable when the current is passed through the motor 1 again, and the convergence speed in estimating the secondary magnetic flux ⁇ dr, the secondary magnetic flux ⁇ dr immediately after the switching of the wiring connection is determined. There is a risk that an incorrect estimate will be made.
  • the control unit 30 estimates the secondary magnetic flux ⁇ dr again, and Determine the success or failure of switching.
  • control unit 30 can determine that the switching has failed even though the switching of the wiring has been performed normally, or that the switching has been performed normally even though the switching has failed. It is possible to prevent the determination that the
  • the control unit 30 included in the drive device 100 estimates the secondary magnetic flux before switching, and estimates the secondary magnetic flux before switching.
  • the demagnetization level is determined by comparing the estimated value of the secondary magnetic flux and the preset induced voltage constant in the state of the first connection, and the connection switching device 20 switches to the second connection. , estimate the secondary magnetic flux after switching, and compare the estimated value of the secondary magnetic flux after switching with a value in which a preset induced voltage constant in the state of the second connection is corrected based on the demagnetization level. This determines the success or failure of connection switching.
  • the drive device 100 compares the estimated value of the secondary magnetic flux ⁇ dr after switching the wiring connection with the preset value of the induced voltage constant ⁇ a in the state after switching the wiring connection, which is corrected based on the demagnetization level. Thus, regardless of the demagnetization level of the electric motor 1, it is possible to appropriately determine the success or failure of wiring connection switching.
  • FIG. 8 is a diagram showing the configuration of an air conditioner 200 according to the second embodiment.
  • Air conditioner 200 includes drive device 100 described in Embodiment 1.
  • drive device 100 drives electric motor 1 that drives compressor 904 included in air conditioner 200. That is, the air conditioner 200 has the electric motor 1 driven by the drive device 100.
  • the air conditioner 200 further includes a compressor 904 that compresses the refrigerant of the refrigeration cycle 900 using the electric motor 1 as a drive source.
  • the refrigeration cycle 900 can perform heating operation or cooling operation by switching the four-way valve 902.
  • heating operation as shown by the solid arrow, the refrigerant is pressurized by the compressor 904 and sent out, and the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910, and the four-way valve 902 are compressed. and returns to the compressor 904.
  • cooling operation as indicated by the dashed arrow, the refrigerant is pressurized by the compressor 904 and sent out, passing through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906, and the four-way valve 902. and returns to the compressor 904.
  • the drive device 100 connected to the AC power source 2 performs variable speed control to drive the electric motor 1, and the electric motor 1 drives the compressor 904.
  • indoor heat exchanger 906 functions as a condenser
  • outdoor heat exchanger 910 functions as an evaporator
  • the outdoor heat exchanger 910 functions as a condenser
  • the indoor heat exchanger 906 functions as an evaporator to absorb heat.
  • the expansion valve 908 reduces the pressure of the refrigerant and expands it.
  • the pressure ratio of the compressor 904 changes depending on the degree of indoor temperature adjustment, and if the indoor set temperature and the indoor actual temperature are significantly different, the drive device 100 increases the rotational speed of the electric motor 1, Creates a highly compressed state.
  • the air conditioner 200 since the air conditioner 200 according to the second embodiment includes the drive device 100 described in the first embodiment, the electric motor 1 is activated in accordance with the driving situation without stopping the compressor 904. Connections can be switched, and air conditioning operation can be continued. That is, the air conditioner 200 can improve user comfort. In addition, since the connection switching success/failure determination is performed correctly, the air conditioner 200 can stop the inverter 4 included in the drive device 100 when the connection switching is abnormal, and the air conditioner 200 can continue to operate in a state where the connection is abnormal. This can be prevented.
  • FIG. 9 is a diagram showing the processor 91 in a case where part or all of the control unit 30 included in the drive device 100 according to the first embodiment is implemented by the processor 91. That is, some or all of the functions of the control unit 30 may be realized by the processor 91 that executes a program stored in the memory 92.
  • the processor 91 is a CPU (Central Processing Unit), a processing system, an arithmetic system, a microprocessor, or a DSP (Digital Signal Processor).
  • a memory 92 is also shown in FIG.
  • control unit 30 When some or all of the functions of the control unit 30 are realized by the processor 91, some or all of the functions are realized by the processor 91, software, firmware, or a combination of software and firmware. Software or firmware is written as a program and stored in memory 92. The processor 91 implements some or all of the functions of the control unit 30 by reading and executing programs stored in the memory 92 .
  • the drive device 100 stores a program that results in some or all of the steps executed by the control unit 30. It has a memory 92 for storing data. It can be said that the program stored in the memory 92 causes the computer to execute at least part of the procedure or method executed by the control unit 30.
  • the memory 92 is, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (registered trademark) (Electrically Erasable Programmable Read-Only Memory). ) etc. non-volatile Alternatively, it may be a volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD (Digital Versatile Disk), or the like.
  • FIG. 10 is a diagram showing a processing circuit 93 in a case where part or all of the control unit 30 included in the drive device 100 according to the first embodiment is implemented by the processing circuit 93. That is, part or all of the control unit 30 may be realized by the processing circuit 93.
  • the processing circuit 93 is dedicated hardware.
  • the processing circuit 93 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. It is.
  • a part of the control unit 30 may be realized by dedicated hardware separate from the rest of the control unit 30.
  • some of the plurality of functions may be realized by software or firmware, and the remainder of the plurality of functions may be realized by dedicated hardware. In this way, the plurality of functions of the control unit 30 can be realized by hardware, software, firmware, or a combination thereof.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

A drive device (100) includes: a converter (3) that rectifies AC voltage supplied from an AC power supply (2); an inverter (4) that generates, from the rectified voltage obtained by the converter (3) AC voltage corresponding to a set rotational speed, and supplies said AV voltage to an electric motor (1); a connection switching device (20) that switches a connection state of a wiring of the electric motor (1) in accordance with a switching command; and a control unit (30). The control unit (30): estimates, after a first connection is selected by the connection switching device (30), secondary magnetic flux before switching; determines a demagnetization level by comparing the estimated value of the secondary magnetic flux before switching and a predetermined induced voltage constant in a first connection state; estimates, after switching to a second connection by the connection switching device (20) is performed, a secondary magnetic flux after switching; and performs a determination of connection switching success or failure by comparing the estimated value of the secondary magnetic flux after switching and a value obtained by correcting on the basis of the demagnetization level a predetermined induced voltage constant in a second connection state.

Description

駆動装置及び空気調和装置Drive equipment and air conditioning equipment
 本開示は、結線状態が切り替え可能な電動機をインバータによって駆動する駆動装置と、当該駆動装置を有する空気調和装置とに関する。 The present disclosure relates to a drive device that uses an inverter to drive an electric motor whose wiring state can be switched, and an air conditioner that includes the drive device.
 従来、電動機が有する固定子の巻線を複数の異なる結線状態のいずれかに切り替える結線切替装置を有していて、電動機の動作中に巻線の結線を切り替えることが可能な駆動装置が知られている。例えば、電流がゼロである状態で電動機の巻線の切り替えを行い、切り替えの前後での誘起電圧及び速度についての値を比較することにより巻線の切り替え判定を行う駆動装置が知られている(例えば、特許文献1参照)。特許文献2は、適応観測器を用いて誘起電圧及び二次磁束を含む磁束情報を推定する方法を開示している。 Conventionally, there has been known a drive device that has a connection switching device that switches the windings of a stator of an electric motor into one of a plurality of different connection states, and is capable of switching the connection of the windings while the motor is operating. ing. For example, there is a known drive device that switches the windings of a motor in a state where the current is zero and determines whether the windings should be switched by comparing the values of the induced voltage and speed before and after the switching. For example, see Patent Document 1). Patent Document 2 discloses a method of estimating magnetic flux information including induced voltage and secondary magnetic flux using an adaptive observation device.
特開2008-148490号公報Japanese Patent Application Publication No. 2008-148490 国際公開第2002/091558号International Publication No. 2002/091558
 従来の技術では、結線の切り替えが正しく行われたかを確認するために、結線の切り替えの前後での誘起電圧定数に相当する値を比較することで結線の切り替えの成否が判断される。圧縮機モータが永久磁石型モータで、モータが減磁していた場合、従来の技術には、誘起電圧定数が想定の値よりも小さな値となることから切り替えの判断が難しいという課題がある。 In conventional technology, in order to confirm whether the wiring connection has been switched correctly, the success or failure of the wiring connection is determined by comparing values corresponding to the induced voltage constants before and after the wiring connection switching. If the compressor motor is a permanent magnet type motor and the motor is demagnetized, the problem with conventional technology is that it is difficult to determine whether to switch because the induced voltage constant is smaller than the expected value.
 本開示は、上記に鑑みてなされたものであって、電動機の減磁レベルによらず、結線切替成否判定を適切に行うことができる駆動装置を得ることを目的とする。 The present disclosure has been made in view of the above, and an object of the present disclosure is to provide a drive device that can appropriately determine the success or failure of wire connection switching, regardless of the demagnetization level of the electric motor.
 上述した課題を解決し、目的を達成するために、本開示に係る駆動装置は、交流電源から供給された交流電圧を整流するコンバータと、コンバータによって得られた整流電圧から設定回転速度に対応する交流電圧を生成して電動機に供給するインバータと、切り替え指令にしたがって電動機の巻線の結線状態を切り替える結線切替装置と、電動機の負荷電流を検出する検出部と、インバータ及び結線切替装置を制御する制御部とを有する。制御部は、結線切替装置により第1の結線が選択された後、切り替え前の二次磁束を推定し、切り替え前の二次磁束の推定値と第1の結線の状態における予め設定された誘起電圧定数とを比較することで減磁レベルを判定し、結線切替装置により第2の結線への切り替えが行われた後、切り替え後の二次磁束を推定し、切り替え後の二次磁束の推定値と第2の結線の状態における予め設定された誘起電圧定数が減磁レベルに基づいて補正された値とを比較することで結線切替成否判定を行う。 In order to solve the above-mentioned problems and achieve the purpose, a drive device according to the present disclosure includes a converter that rectifies an AC voltage supplied from an AC power source, and a set rotation speed that corresponds to a set rotation speed from the rectified voltage obtained by the converter. An inverter that generates an alternating current voltage and supplies it to the motor, a connection switching device that switches the connection state of the motor windings according to a switching command, a detection unit that detects the load current of the motor, and controls the inverter and the connection switching device. It has a control section. After the first connection is selected by the connection switching device, the control unit estimates the secondary magnetic flux before switching, and calculates the estimated value of the secondary magnetic flux before switching and the preset induction in the state of the first connection. The demagnetization level is determined by comparing it with the voltage constant, and after switching to the second connection is performed by the connection switching device, the secondary magnetic flux after switching is estimated, and the secondary magnetic flux after switching is estimated. The success or failure of connection switching is determined by comparing the value with a value obtained by correcting a preset induced voltage constant in the second connection state based on the demagnetization level.
 本開示に係る駆動装置は、電動機の減磁レベルによらず、結線切替成否判定を適切に行うことができるという効果を奏する。 The drive device according to the present disclosure has the effect that it is possible to appropriately determine the success or failure of wire connection switching, regardless of the demagnetization level of the electric motor.
実施の形態1に係る駆動装置の構成を示す図A diagram showing the configuration of a drive device according to Embodiment 1 実施の形態1に係る電動機の固定子の巻線及び結線切替装置を詳細に示す図A diagram showing details of the stator winding and connection switching device of the electric motor according to Embodiment 1. 実施の形態1に係る駆動装置が有する結線切替装置の切替器の詳細を示す配線図Wiring diagram showing details of a switching device of a wiring switching device included in the drive device according to Embodiment 1 電動機の結線がY結線である場合の固定子の巻線の接続状態を概念的に示す図A diagram conceptually showing the connection state of the stator windings when the motor is Y-connected. 電動機の結線がΔ結線である場合の固定子の巻線の接続状態を概念的に示す図A diagram conceptually showing the connection state of the stator windings when the motor connection is delta connection. 実施の形態1に係る駆動装置が有する制御部の構成を示す図A diagram showing the configuration of a control section included in the drive device according to Embodiment 1. 実施の形態1における結線の切り替えが行われる際の制御シーケンスを説明するための図A diagram for explaining a control sequence when switching connections in Embodiment 1 実施の形態2に係る空気調和装置の構成を示す図A diagram showing the configuration of an air conditioner according to Embodiment 2 実施の形態1に係る駆動装置が有する制御部の一部又は全部がプロセッサによって実現される場合のプロセッサを示す図A diagram illustrating a processor when part or all of the control unit included in the drive device according to Embodiment 1 is implemented by a processor. 実施の形態1に係る駆動装置が有する制御部の一部又は全部が処理回路によって実現される場合の処理回路を示す図A diagram showing a processing circuit when part or all of the control unit included in the drive device according to Embodiment 1 is realized by a processing circuit.
 以下に、実施の形態に係る駆動装置及び空気調和装置を図面に基づいて詳細に説明する。 Below, a drive device and an air conditioner according to an embodiment will be described in detail based on the drawings.
実施の形態1.
 図1は、実施の形態1に係る駆動装置100の構成を示す図である。駆動装置100は、負荷5に接続された電動機1を駆動する装置であって、コンバータ3と、インバータ4と、結線切替装置20と、制御部30とを有する。図1には、電動機1、交流電源2及び負荷5も示されている。
Embodiment 1.
FIG. 1 is a diagram showing the configuration of a drive device 100 according to the first embodiment. The drive device 100 is a device that drives the electric motor 1 connected to the load 5, and includes a converter 3, an inverter 4, a connection switching device 20, and a control section 30. Also shown in FIG. 1 are a motor 1, an AC power source 2, and a load 5.
 コンバータ3は、交流電源2から供給された交流電圧を受けて、当該交流電圧を整流して直流電圧を出力する。以下では、コンバータ3から出力される直流電圧は「母線電圧」と記載される場合がある。コンバータ3は、ダイオードブリッジを用いて整流を行うコンバータであってもよいし、リアクタと制御部30によって制御されるスイッチング素子とを用いて母線電圧を上昇させることができる昇圧コンバータであってもよい。 The converter 3 receives the AC voltage supplied from the AC power supply 2, rectifies the AC voltage, and outputs the DC voltage. Hereinafter, the DC voltage output from converter 3 may be referred to as "bus voltage." The converter 3 may be a converter that performs rectification using a diode bridge, or may be a boost converter that can increase the bus voltage using a reactor and a switching element controlled by the control unit 30. .
 インバータ4は、制御部30によって制御され、コンバータ3によって得られた整流電圧から設定回転速度に対応する交流電圧を生成して電動機1に供給する。更に言うと、インバータ4は、コンバータ3から出力された直流電圧を電圧可変かつ周波数可変の交流電圧に変換して電動機1を駆動する。制御部30は、インバータ4が出力する電動機1への負荷電流に基づいてインバータ4を制御する。駆動装置100は、電動機1の負荷電流を検出する検出部6a,6bを更に有する。検出部6a,6bは、図1に示されるように電動機1の負荷電流を直接検出する公知のACCT(Alternating Current Current Transformer)又はDCCT(Direct Current Current Transformer)といった電流センサであってもよいし、後述の図6に示されるようにコンバータ3とインバータ4との間を流れる母線電流を検出して電動機1の負荷電流を推定する構成要素であってもよい。検出部6a,6bが行う検出方法又は推定方法は、限定されない。検出部6a,6bによって検出された負荷電流の情報は、制御部30に取り込まれる。 The inverter 4 is controlled by the control unit 30 and generates an AC voltage corresponding to the set rotational speed from the rectified voltage obtained by the converter 3 and supplies it to the electric motor 1. More specifically, the inverter 4 converts the DC voltage output from the converter 3 into an AC voltage whose voltage is variable and whose frequency is variable, and drives the motor 1. The control unit 30 controls the inverter 4 based on the load current to the electric motor 1 that the inverter 4 outputs. The drive device 100 further includes detection units 6a and 6b that detect the load current of the electric motor 1. The detection units 6a and 6b may be a known current sensor such as ACCT (Alternating Current Transformer) or DCCT (Direct Current Transformer) that directly detects the load current of the motor 1 as shown in FIG. It may be a component that detects a bus current flowing between a converter 3 and an inverter 4 and estimates the load current of the electric motor 1, as shown in FIG. 6, which will be described later. The detection method or estimation method performed by the detection units 6a and 6b is not limited. Information on the load current detected by the detection units 6a and 6b is taken into the control unit 30.
 電動機1は三相同期電動機であって、固定子の巻線の端部が電動機1の外部に引き出されており、電動機1の巻線は、Y結線にもなり得るしΔ結線にもなり得る。Y結線はスター結線であり、Δ結線はデルタ結線である。結線切替装置20は、切り替え指令にしたがって電動機1の巻線の結線状態を切り替える。つまり、結線切替装置20は、電動機1の結線を選択する。結線切替装置20は、切替器21,22,23を有する。制御部30は、電動機1をY結線とΔ結線とのうちのどちらの結線で駆動するかを制御する。 The motor 1 is a three-phase synchronous motor, and the ends of the stator windings are drawn out to the outside of the motor 1, and the windings of the motor 1 can be Y-connected or Δ-connected. . The Y connection is a star connection, and the Δ connection is a delta connection. The connection switching device 20 switches the connection state of the windings of the electric motor 1 according to a switching command. That is, the connection switching device 20 selects the connection of the electric motor 1. The connection switching device 20 includes switching devices 21, 22, and 23. The control unit 30 controls which connection to drive the electric motor 1, the Y connection or the Δ connection.
 図2は、実施の形態1に係る電動機1の固定子の巻線及び結線切替装置20を詳細に示す図である。図2に示されるように、電動機1のU相、V相及びW相から成る三つの相の巻線41,42,43の第1の端部41a,42a,43aは、駆動装置100の外部端子41c,42c,43cに接続されている。具体的には、第1の端部41aは駆動装置100の外部端子41cに接続されており、第1の端部42aは駆動装置100の外部端子42cに接続されており、第1の端部43aは駆動装置100の外部端子43cに接続されている。第1の端部41a,42a,43aは、インバータ4のU相、V相及びW相の出力にも接続されている。 FIG. 2 is a diagram showing details of the stator winding and connection switching device 20 of the electric motor 1 according to the first embodiment. As shown in FIG. 2, the first ends 41a, 42a, 43a of the three- phase windings 41, 42, 43 consisting of the U-phase, V-phase, and W-phase of the electric motor 1 are connected to the outside of the drive device 100. It is connected to terminals 41c, 42c, and 43c. Specifically, the first end 41a is connected to the external terminal 41c of the drive device 100, the first end 42a is connected to the external terminal 42c of the drive device 100, and the first end 41a is connected to the external terminal 42c of the drive device 100. 43a is connected to an external terminal 43c of the drive device 100. The first ends 41a, 42a, 43a are also connected to the U-phase, V-phase, and W-phase outputs of the inverter 4.
 電動機1の三つの相の巻線41,42,43の第2の端部41b,42b,43bは、駆動装置100の外部端子41d,42d,43dに接続されている。具体的には、第2の端部41bは駆動装置100の外部端子41dに接続されており、第2の端部42bは駆動装置100の外部端子42dに接続されており、第2の端部43bは駆動装置100の外部端子43dに接続されている。外部端子41c,42c,43c,41d,42d,43dは、結線切替装置20に接続されている。 The second ends 41b, 42b, 43b of the three phase windings 41, 42, 43 of the electric motor 1 are connected to external terminals 41d, 42d, 43d of the drive device 100. Specifically, the second end 41b is connected to the external terminal 41d of the drive device 100, the second end 42b is connected to the external terminal 42d of the drive device 100, and the second end 41b is connected to the external terminal 41d of the drive device 100. 43b is connected to an external terminal 43d of the drive device 100. The external terminals 41c, 42c, 43c, 41d, 42d, and 43d are connected to the connection switching device 20.
 結線切替装置20は、上述の通り切替器21,22,23を有する。切替器21には巻線41に流れる電流が流れ、切替器22には巻線42に流れる電流が流れ、切替器23には巻線43に流れる電流が流れる。切替器21は巻線41に流れる電流の経路を切り替える機能を有しており、切替器22は巻線42に流れる電流の経路を切り替える機能を有しており、切替器23は巻線43に流れる電流の経路を切り替える機能を有している。切替器21,22,23としては、電磁的に接点が開閉する電磁接触器が用いられる。当該電磁接触器には、リレー及びコンタクターと呼ばれる構成要素が含まれる。当該電磁接触器の構成は、例えば図3に示される構成であり、励磁コイル211,221,231に電流が流されている場合と、電流が流されていない場合とで、当該電磁接触器は異なる接続状態となる。 The connection switching device 20 has the switching devices 21, 22, and 23 as described above. The current flowing through the winding 41 flows through the switch 21, the current flowing through the winding 42 flows through the switch 22, and the current flowing through the winding 43 flows through the switch 23. The switch 21 has the function of switching the path of the current flowing through the winding 41, the switch 22 has the function of switching the path of the current flowing through the winding 42, and the switch 23 has the function of switching the path of the current flowing through the winding 43. It has the function of switching the path of flowing current. As the switching devices 21, 22, and 23, electromagnetic contactors whose contacts are electromagnetically opened and closed are used. The electromagnetic contactor includes components called a relay and a contactor. The configuration of the electromagnetic contactor is, for example, the configuration shown in FIG. The connection status will be different.
 図3は、実施の形態1に係る駆動装置100が有する結線切替装置20の切替器21,22,23の詳細を示す配線図である。励磁コイル211,221,231については、制御部30から出力される結線選択信号Scにより制御される半導体スイッチ204によって、励磁コイル211,221,231と電源25との接続状態が切り替わり、電流の有無も切り替わる。例えば、結線選択信号Scが第1の値を示している場合、半導体スイッチ204はオフとなり、励磁コイル211,221,231には電流は流れず、結線選択信号Scが第2の値を示している場合、半導体スイッチ204はオンとなり、励磁コイル211,221,231へ電流が流れる。第1の値は例えばLowであり、第2の値は例えばHighである。結線選択信号Scが、十分な電流容量を持つ回路から出力される場合、励磁コイル211,221,231は、半導体スイッチ204を介さずに結線選択信号Scで直接駆動されてもよい。 FIG. 3 is a wiring diagram showing details of the switches 21, 22, and 23 of the connection switching device 20 included in the drive device 100 according to the first embodiment. Regarding the excitation coils 211, 221, 231, the connection state between the excitation coils 211, 221, 231 and the power supply 25 is switched by the semiconductor switch 204 controlled by the connection selection signal Sc output from the control unit 30, and the presence or absence of current is switched. is also switched. For example, when the connection selection signal Sc indicates the first value, the semiconductor switch 204 is turned off, no current flows through the excitation coils 211, 221, and 231, and the connection selection signal Sc indicates the second value. If so, the semiconductor switch 204 is turned on, and current flows to the excitation coils 211, 221, and 231. The first value is, for example, Low, and the second value is, for example, High. If the connection selection signal Sc is output from a circuit with sufficient current capacity, the exciting coils 211, 221, 231 may be directly driven by the connection selection signal Sc without using the semiconductor switch 204.
 切替器21について、共通接点21cはリード線を介して外部端子41dに接続されており、常閉接点21bは中性点ノード24に接続されており、常開接点21aはインバータ4のW相の出力に接続されている。切替器22について、共通接点22cはリード線を介して外部端子42dに接続されており、常閉接点22bは中性点ノード24に接続されており、常開接点22aはインバータ4のV相の出力に接続されている。切替器23について、共通接点23cはリード線を介して外部端子43dに接続されており、常閉接点23bは中性点ノード24に接続されており、常開接点23aはインバータ4のU相の出力に接続されている。 Regarding the switch 21, the common contact 21c is connected to the external terminal 41d via a lead wire, the normally closed contact 21b is connected to the neutral node 24, and the normally open contact 21a is connected to the W phase of the inverter 4. connected to the output. Regarding the switch 22, the common contact 22c is connected to the external terminal 42d via a lead wire, the normally closed contact 22b is connected to the neutral node 24, and the normally open contact 22a is connected to the V phase of the inverter 4. connected to the output. Regarding the switch 23, the common contact 23c is connected to the external terminal 43d via a lead wire, the normally closed contact 23b is connected to the neutral node 24, and the normally open contact 23a is connected to the U phase of the inverter 4. connected to the output.
 励磁コイル211,221,231に電流が流れていない場合、図3に示されるように、切替器21,22,23が常閉接点21b,22b,23bの側に切り替わった状態、すなわち、共通接点21c,22c,23cが常閉接点21b,22b,23bに接続された状態になる。この状態では、巻線41,42,43の第2の端部41b,42b,43bは、切替器21,22,23を介して中性点ノード24において接続される。したがって、電動機1の結線の状態は、Y結線の状態になる。 When no current flows through the excitation coils 211, 221, 231, the switches 21, 22, 23 are switched to the normally closed contacts 21b, 22b, 23b, as shown in FIG. 21c, 22c, and 23c are connected to normally closed contacts 21b, 22b, and 23b. In this state, the second ends 41b, 42b, 43b of the windings 41, 42, 43 are connected at the neutral node 24 via the switches 21, 22, 23. Therefore, the wiring state of the electric motor 1 becomes a Y-connection state.
 励磁コイル211,221,231に電流が流れている場合、図3に示されている場合と逆に、切替器21,22,23が常開接点21a,22a,23aの側に切り替わった状態、すなわち、共通接点21c,22c,23cが常開接点21a,22a,23aに接続された状態になる。この状態では、巻線41,42,43の第2の端部41b,42b,43bは、切替器21,22,23を介して巻線43,42,41の第1の端部42a,43a,41aに接続される。したがって、電動機1の結線の状態は、Δ結線の状態になる。 When current is flowing through the excitation coils 211, 221, 231, the switches 21, 22, 23 are switched to the normally open contacts 21a, 22a, 23a, contrary to the case shown in FIG. That is, the common contacts 21c, 22c, and 23c are connected to the normally open contacts 21a, 22a, and 23a. In this state, the second ends 41b, 42b, 43b of the windings 41, 42, 43 are connected to the first ends 42a, 43a of the windings 43, 42, 41 via the switch 21, 22, 23. , 41a. Therefore, the connection state of the electric motor 1 is a Δ connection state.
 以上より、結線選択信号Scが第1の値、例えばLowを示す場合、電動機1はY結線の状態になり、結線選択信号Scが第2の値、例えばHighを示す場合、電動機1はΔ結線の状態になる。 From the above, when the connection selection signal Sc indicates the first value, for example Low, the motor 1 is in the Y connection state, and when the connection selection signal Sc indicates the second value, for example High, the motor 1 is in the Δ connection state. becomes the state of
 電動機1がY結線とΔ結線とのうちのいずれへの切り替えも可能である構成の利点について図4及び図5を用いて以下説明する。図4は、電動機1の結線がY結線である場合の固定子の巻線の接続状態を概念的に示す図である。図5は、電動機1の結線がΔ結線である場合の固定子の巻線の接続状態を概念的に示す図である。 The advantages of the configuration in which the electric motor 1 can be switched to either the Y connection or the Δ connection will be described below with reference to FIGS. 4 and 5. FIG. 4 is a diagram conceptually showing the connection state of the stator windings when the electric motor 1 is connected in a Y-connection. FIG. 5 is a diagram conceptually showing the connection state of the stator windings when the electric motor 1 is connected in a Δ connection.
 Y結線時の線間電圧をV、流れ込む電流をIとし、Δ結線時の線間電圧をVΔ、流れ込む電流をIΔとし、各相の巻線に掛かる電圧が等しいとすると、
 VΔ=V/√3  ・・・(1)
の関係が成り立ち、このとき、
 IΔ=√3×I  ・・・(2)
の関係が得られることが周知されている。
Assuming that the line voltage during Y connection is V Y , the flowing current is I Y , the line voltage during Δ connection is V Δ , the flowing current is I Δ , and the voltages applied to the windings of each phase are equal,
= VY /√3...(1)
The relationship holds, and at this time,
I Δ =√3×I Y ...(2)
It is well known that the following relationship can be obtained.
 Y結線時の電圧V及び電流Iと、Δ結線時の電圧VΔ及び電流IΔとが式(1)及び式(2)の関係を満たす場合、Y結線時とΔ結線時とで電動機1に供給される電力は等しい。つまり、電動機1に供給される電力がY結線時とΔ結線時とで等しい場合、Δ結線の方が電流は大きく、駆動に必要な電圧が低い。Y結線時とΔ結線時との違いは電動機定数にも表れ、電動機1が三相同期電動機である場合、誘起電圧定数φaは、永久磁石の電機子鎖交磁束の実効値であり、理想的には式(3)の関係が成り立つ。
 φaY=√3×φaΔ  ・・・(3)
 φaYはY結線時の誘起電圧定数であり、φaΔはΔ結線時の誘起電圧定数である。Y結線時とΔ結線時とで電動機1の許容電流も異なり、許容電流はΔ結線時の方が大きい。
If the voltage V Y and current I Y during Y connection and the voltage V Δ and current I Δ during Δ connection satisfy the relationship of equations (1) and (2), then the relationship between Y connection and Δ connection is The power supplied to the electric motor 1 is equal. That is, when the electric power supplied to the motor 1 is equal between the Y connection and the Δ connection, the current is larger in the Δ connection and the voltage required for driving is lower. The difference between the Y connection and the Δ connection is also reflected in the motor constant. When the motor 1 is a three-phase synchronous motor, the induced voltage constant φa is the effective value of the armature flux linkage of the permanent magnet, and is ideal. The relationship of equation (3) holds true.
φ aY =√3×φ ...(3)
φ aY is an induced voltage constant during Y connection, and φ is an induced voltage constant during Δ connection. The allowable current of the motor 1 also differs between Y-connection and Δ-connection, and the allowable current is larger in Δ-connection.
 同期電動機が用いられる場合、回転速度が上がると、つまり負荷が大きいと、逆起電力が増加し、駆動に必要な電圧値が増加する。この起電力は、上述のようにY結線の方がΔ結線に比べて大きい。 When a synchronous motor is used, when the rotational speed increases, that is, when the load increases, the back electromotive force increases and the voltage value required for driving increases. As described above, this electromotive force is larger in the Y connection than in the Δ connection.
 高速での逆起電力を抑制するために、永久磁石の磁力を小さくしたり、固定子の巻線の巻き数を減らしたりすることが考えられる。しかし、そのようにすると、同一の出力トルクを得るための電流が増加するため、電動機1及びインバータ4に流れる電流が増加し、電動機1を駆動する効率が低下する。 In order to suppress the back electromotive force at high speeds, it is possible to reduce the magnetic force of the permanent magnet or reduce the number of turns of the stator winding. However, in this case, since the current required to obtain the same output torque increases, the current flowing through the electric motor 1 and the inverter 4 increases, and the efficiency of driving the electric motor 1 decreases.
 そこで、回転速度に対応して結線を切り替えることが考えられる。例えば、高速回転が必要な場合、Δ結線とする。こうすることで、駆動に必要な電圧を、Y結線時の1/√3にすることができる。更に言うと、巻線の巻き数を減らす必要がなくなり、電動機1を駆動する効率は低下しない。なお、高速回転は大きい負荷に対応する。 Therefore, it is possible to switch the wiring according to the rotation speed. For example, if high-speed rotation is required, use Δ connection. By doing so, the voltage required for driving can be reduced to 1/√3 of the Y-connection. Furthermore, there is no need to reduce the number of turns of the winding, and the efficiency of driving the electric motor 1 does not decrease. Note that high-speed rotation corresponds to a large load.
 他方、低速回転では、電動機1の結線をY結線とすることで、電流値をΔ結線時の1/√3にすることができる。さらに、巻数をY結線で低速回転での駆動に適したように設計することが可能となり、Y結線を速度範囲の全域にわたり使用する場合に比べて、電流値を低減することができるため、電動機1を駆動する効率を高めることが可能となる。なお、低速回転は小さい負荷に対応する。 On the other hand, at low speed rotation, by connecting the electric motor 1 to a Y connection, the current value can be reduced to 1/√3 of the Δ connection. Furthermore, the number of turns can be designed to be suitable for driving at low speeds with a Y connection, and the current value can be reduced compared to when a Y connection is used over the entire speed range. This makes it possible to increase the efficiency of driving 1. Note that low speed rotation corresponds to a small load.
 以上のことから、回転速度、つまり負荷条件に対応して結線を切り替えることができれば、低負荷時の効率を向上させることができ、高負荷時の高出力化も可能となる。 From the above, if it is possible to switch the wiring according to the rotational speed, that is, the load condition, it is possible to improve the efficiency at low loads, and it is also possible to increase the output at high loads.
 制御部30は、インバータ4及び結線切替装置20を制御する。制御部30は、インバータ4を制御してインバータ4からの出力電圧の周波数及び電圧値を変化させる。制御部30は、結線切替装置20を制御して電動機1の結線を選択する。コンバータ3が昇圧コンバータである場合、制御部30は当該昇圧コンバータも制御して母線電圧を変化させる。 The control unit 30 controls the inverter 4 and the connection switching device 20. The control unit 30 controls the inverter 4 to change the frequency and voltage value of the output voltage from the inverter 4. The control unit 30 controls the connection switching device 20 to select the connection of the electric motor 1 . When converter 3 is a boost converter, control unit 30 also controls the boost converter to change the bus voltage.
 図6は、実施の形態1に係る駆動装置100が有する制御部30の構成を示す図である。図6には、駆動装置100が有するすべての構成要素、電動機1、交流電源2及び負荷5が示されている。制御部30は、図6に示されるように、運転指令部31と、インバータ制御部32とを有し、コンバータ3が昇圧コンバータである場合、昇圧コンバータを制御するための制御部も有する。 FIG. 6 is a diagram showing the configuration of the control section 30 included in the drive device 100 according to the first embodiment. FIG. 6 shows all the components that the drive device 100 has, the electric motor 1, the AC power source 2, and the load 5. As shown in FIG. 6, control section 30 includes an operation command section 31 and an inverter control section 32, and, when converter 3 is a boost converter, also has a control section for controlling the boost converter.
 運転指令部31は、周波数指令値ωと、ゼロ選択信号Szと、結線選択信号Scとを出力する。周波数指令値ω及びゼロ選択信号Szはインバータ制御部32に供給される。周波数指令値ωは、運転状態に適した値に設定される。コンバータ3が昇圧コンバータである場合、母線電圧指令値は運転状態に適した値に設定され、母線は任意の値に昇圧される。インバータ制御部32は、インバータ4のスイッチング動作を司るPWM(Pulse Width Modulation)信号Smをインバータ4へ出力し、インバータ4の出力電圧の周波数及び電圧値を変化させる。 The operation command unit 31 outputs a frequency command value ω * , a zero selection signal Sz, and a connection selection signal Sc. The frequency command value ω * and the zero selection signal Sz are supplied to the inverter control section 32. The frequency command value ω * is set to a value suitable for the operating state. When the converter 3 is a boost converter, the bus voltage command value is set to a value suitable for the operating state, and the bus voltage is boosted to an arbitrary value. The inverter control unit 32 outputs a PWM (Pulse Width Modulation) signal Sm that controls the switching operation of the inverter 4 to the inverter 4, and changes the frequency and voltage value of the output voltage of the inverter 4.
 結線選択信号Scは、Y結線が選択された場合、第1の値、例えばLowを示し、Δ結線が選択される場合、第2の値、例えばHighを示す。 The connection selection signal Sc indicates a first value, for example, Low, when the Y connection is selected, and indicates a second value, for example, High, when the Δ connection is selected.
 ゼロ選択信号Szは、通常は第1の値、例えばLowを示し、後述のゼロ電流制御の期間中には第2の値、例えばHighを示す。 The zero selection signal Sz normally indicates a first value, eg, Low, and indicates a second value, eg, High, during the period of zero current control, which will be described later.
 運転指令部31は、例えば、電動機1の固定子の巻線をY結線とするかΔ結線とするかの決定及び目標回転速度の決定及び結線の切替成否判定を行い、決定に基づき結線選択信号Sc、周波数指令値ω及びインバータ停止信号Soを出力する。インバータ停止信号Soは、結線状態に異常がない場合、通常は第1の値、例えばLowを示し、後述の結線切替成否判定にて切り替えが失敗したと判断された場合、第2の値、例えばHighを示す。 For example, the operation command unit 31 determines whether the stator windings of the electric motor 1 are Y-connected or Δ-connected, determines the target rotation speed, and determines the success or failure of switching the connections, and issues a connection selection signal based on the determination. Sc, frequency command value ω * , and inverter stop signal So are output. The inverter stop signal So normally indicates a first value, e.g., Low, when there is no abnormality in the connection state, and when it is determined that the switching has failed in the connection switching success/failure determination described later, it takes a second value, e.g. Indicates High.
 例えば電動機1に接続されている負荷5が空気調和装置である場合、運転指令部31は、室温と設定温度との差が大きいときは電動機1の結線をΔ結線とすることを決め、結線選択信号Scを第2の値、例えばHighを示す信号とし、目標回転速度を比較的高い値に設定し、起動後に上記の目標回転速度に対応する周波数まで徐々に周波数を上昇させる周波数指令値ωを出力する。周波数が目標回転速度に対応する周波数に達したら、運転指令部31は、室温が設定温度に近づくまで、状態を維持し、室温が設定温度に近くなったら、電動機1の結線をY結線に切り替えるために、結線選択信号Scを第1の値、例えばLowを示す信号とし、その後に室温が設定温度に近い状態を維持するための制御を行う。この制御には、周波数の調整、並びに電動機1の停止及び再起動等が含まれる。 For example, when the load 5 connected to the electric motor 1 is an air conditioner, the operation command unit 31 decides to connect the electric motor 1 to a Δ connection when the difference between the room temperature and the set temperature is large, and selects the connection. A frequency command value ω * that sets the signal Sc to a second value, for example, a signal indicating High, sets the target rotation speed to a relatively high value, and gradually increases the frequency to the frequency corresponding to the target rotation speed after startup. Output. When the frequency reaches the frequency corresponding to the target rotational speed, the operation command unit 31 maintains the state until the room temperature approaches the set temperature, and when the room temperature approaches the set temperature, switches the connection of the electric motor 1 to the Y connection. Therefore, the connection selection signal Sc is set to a first value, for example, a signal indicating Low, and then control is performed to maintain the room temperature close to the set temperature. This control includes frequency adjustment, stopping and restarting the electric motor 1, and the like.
 電動機1が三相同期電動機である場合、理想的には誘起電圧定数φaと二次磁束φdrの値とは同値となるため、二次磁束φdrの推定値の変化に基づいて結線状態を判定することができる。ただし、永久磁石の温度依存性により減磁又は増磁が生じる。例えば、電動機1を構成する永久磁石が高温で減磁する磁石である場合、ある温度を超過すると磁力が元に戻らない不可逆減磁が発生し、電動機1の性能が大幅に低下する。また、結線の切り替えの前後で誘起電圧定数φaの値が変わるため、結線の切り替えの前後での二次磁束φdrの推定値の変化において、結線の切り替えによる現象と減磁による影響とを明確に区別した上で、結線の切り替えの状態を判定する必要がある。 When the motor 1 is a three-phase synchronous motor, ideally the induced voltage constant φa and the value of the secondary magnetic flux φdr are the same value, so the connection state is determined based on the change in the estimated value of the secondary magnetic flux φdr. be able to. However, demagnetization or magnetization occurs due to the temperature dependence of the permanent magnet. For example, if the permanent magnets constituting the electric motor 1 are magnets that demagnetize at high temperatures, irreversible demagnetization occurs where the magnetic force does not return to its original state when the temperature exceeds a certain temperature, and the performance of the electric motor 1 is significantly reduced. In addition, since the value of the induced voltage constant φa changes before and after switching the connection, it is possible to clearly distinguish between the phenomenon caused by switching the connection and the effect of demagnetization in the change in the estimated value of the secondary magnetic flux φdr before and after switching the connection. After distinguishing between them, it is necessary to determine the state of wiring switching.
 結線切替成否判定のため、まず、結線の切り替え前の第1の結線状態における誘起電圧定数φaと結線の切り替え後の第2の結線状態における誘起電圧定数φaとが予め設定される。誘起電圧定数φaの設定値は、例えば、電動機1が設計された際の設計値が用いられてもよい。制御部30は、結線の切り替え前の二次磁束φdrを推定する。二次磁束φdrを推定する方法として、上述の通り特許文献2は、適応観測器を用いて誘起電圧及び二次磁束φdrを含む磁束情報を推定する方法を開示している。制御部30は、当該方法と同様の方法用いることによって、二次磁束φdrを推定する。 To determine the success or failure of connection switching, first, the induced voltage constant φa in the first connection state before switching the connection and the induced voltage constant φa in the second connection state after switching the connection are set in advance. For example, a design value when the electric motor 1 was designed may be used as the set value of the induced voltage constant φa. The control unit 30 estimates the secondary magnetic flux φdr before switching the wiring connection. As a method for estimating the secondary magnetic flux φdr, as described above, Patent Document 2 discloses a method of estimating magnetic flux information including the induced voltage and the secondary magnetic flux φdr using an adaptive observation device. The control unit 30 estimates the secondary magnetic flux φdr by using a method similar to this method.
 制御部30は、推定した二次磁束φdrの値と第1の結線状態における予め設定された誘起電圧定数φaとを比較することで減磁レベルを以下の式(4)に基づいて演算する。
 減磁レベル値(%)=二次磁束φdrの推定値/誘起電圧定数φa×100  ・・・(4)
The control unit 30 calculates the demagnetization level based on the following equation (4) by comparing the estimated value of the secondary magnetic flux φdr and a preset induced voltage constant φa in the first connection state.
Demagnetization level value (%) = estimated value of secondary magnetic flux φdr/induced voltage constant φa×100 (4)
 制御部30は、結線の切り替え後に結線切替成否判定を行う場合、結線の切り替え後の二次磁束φdrの値を推定し、結線の切り替え後の、つまり第2の結線状態における誘起電圧定数φaと減磁レベルとを比較して結線切替成否判定を行う場合、式(4)で得られる減磁レベルを考慮して判定を行う。 When determining the success or failure of connection switching after switching the connection, the control unit 30 estimates the value of the secondary magnetic flux φdr after switching the connection, and calculates the value of the induced voltage constant φa after switching the connection, that is, in the second connection state. When determining the success or failure of connection switching by comparing with the demagnetization level, the determination is made in consideration of the demagnetization level obtained by equation (4).
 結線切替動作が実施された後、制御部30は、結線の切り替え後の二次磁束φdrを再度推定し、二次磁束φdrの推定値と結線の切り替え後の第2の結線状態における予め設定された誘起電圧定数φaとを比較し、結線切替成否判定を行う。具体的には、判定値Kが定められ、制御部30は、以下の補正式(5)の補正演算結果と判定値Kとを比較し、演算結果が判定値Kの絶対値を下回れば切り替えが正常であると判定する。
 (二次磁束φdrの推定値)-(誘起電圧定数φa×減磁レベル値(%)/100)  ・・・(5)
After the connection switching operation is performed, the control unit 30 re-estimates the secondary magnetic flux φdr after switching the connection, and calculates the estimated value of the secondary magnetic flux φdr and the preset value in the second connection state after switching the connection. The induced voltage constant φa is compared with the induced voltage constant φa to determine the success or failure of the connection switching. Specifically, the judgment value K is determined, and the control unit 30 compares the correction calculation result of the following correction formula (5) with the judgment value K, and switches if the calculation result is less than the absolute value of the judgment value K. is determined to be normal.
(Estimated value of secondary magnetic flux φdr) - (induced voltage constant φa x demagnetization level value (%)/100) ... (5)
 なお、判定値Kを定めるに当たり、減磁による影響以外に二次磁束φdrの推定値に影響を与える結線の切り替え後の制御収束性のバラツキを考慮し、制御部30は、判定値Kに正負の尤度を持たせて判定を実施する。更に言うと、制御部30は、結線切替成否判定を行う場合、切り替え後の二次磁束φdrの推定値と第2の結線の状態における予め設定された誘起電圧定数φaが減磁レベルに基づいて補正された値とを比較するとき、判定値Kに正負の尤度を持たせて結線切替成否判定を行う。これにより、駆動装置100は、結線の切り替えが正常に行われたにもかかわらず切り替えが失敗したと判定することを防止することができる。 In determining the judgment value K, the control unit 30 sets the judgment value K to a positive or negative value, taking into account the variation in control convergence after switching the wiring, which affects the estimated value of the secondary magnetic flux φdr in addition to the influence of demagnetization. The judgment is performed with a likelihood of . More specifically, when determining the success or failure of connection switching, the control unit 30 determines whether the estimated value of the secondary magnetic flux φdr after switching and the preset induced voltage constant φa in the state of the second connection are based on the demagnetization level. When comparing the corrected value, the determination value K is given a positive or negative likelihood to determine whether the connection switching is successful or not. Thereby, the drive device 100 can prevent determining that the switching has failed even though the switching of the wire connections has been performed normally.
 制御部30は、結線切替成否判定において切り替えが失敗したと判断した場合、インバータ停止信号Soを第2の値、例えばHighを示す信号とすることでPWM信号Smを非アクティブにし、電動機1を停止させる。更に言うと、制御部30は、結線切替成否判定の結果、切替状態が異常であると判断した場合、電動機1を停止させる動作を行う。 If the control unit 30 determines that the switching has failed in the connection switching success/failure determination, the control unit 30 deactivates the PWM signal Sm by setting the inverter stop signal So to a second value, for example, a signal indicating High, and stops the electric motor 1. let More specifically, if the control unit 30 determines that the switching state is abnormal as a result of the connection switching success/failure determination, it performs an operation to stop the electric motor 1 .
 次に、結線切替動作について詳細を説明する。 Next, details of the connection switching operation will be explained.
 運転指令部31は、Y結線とΔ結線とのうちの一方から他方への切り替えのために結線選択信号Scの値を変化させるとともに、結線の切り替え動作中にゼロ選択信号Szの値を一時的に変化させる。 The operation command unit 31 changes the value of the connection selection signal Sc for switching from one of the Y connection and the Δ connection to the other, and also temporarily changes the value of the zero selection signal Sz during the connection switching operation. change to
 例えば、結線の切り替えに際し、運転指令部31は、通常Lowを示すゼロ選択信号Szを、一時的にHighを示す信号とする。ゼロ選択信号SzがHighを示す期間中に、運転指令部31は、結線選択信号Scを、Highを示す信号からLowを示す信号に、又はLowを示す信号からHighを示す信号に切り替える。 For example, when switching the connection, the operation command unit 31 temporarily changes the zero selection signal Sz, which normally indicates Low, to a signal which indicates High. During the period in which the zero selection signal Sz is High, the operation command unit 31 switches the connection selection signal Sc from a High signal to a Low signal, or from a Low signal to a High signal.
 インバータ制御部32は、インバータ4を制御するため、電動機1の負荷電流を検出する検出部から供給される情報に基づいて、PWM信号Smを生成してインバータ4に供給する。PWM信号Smが供給されたインバータ4は、PWM信号Smにしたがって出力の電圧値と周波数とを変化させて電動機1を駆動する。なお、図6では、母線電流Idcについての情報から電動機1の負荷電流を推定する例が示されている。 In order to control the inverter 4, the inverter control unit 32 generates a PWM signal Sm and supplies it to the inverter 4 based on information supplied from the detection unit that detects the load current of the electric motor 1. The inverter 4 supplied with the PWM signal Sm drives the electric motor 1 by changing the output voltage value and frequency according to the PWM signal Sm. Note that FIG. 6 shows an example in which the load current of the motor 1 is estimated from information about the bus current Idc.
 以下、電動機1の運転中に結線切替装置20を動作させる際の駆動装置100の動作について説明する。 Hereinafter, the operation of the drive device 100 when the wire connection switching device 20 is operated while the electric motor 1 is operating will be described.
 電動機1が運転中、すなわち、結線切替装置20を構成する切替器21,22,23に電流が流れている状態で、励磁コイル211,221,231に流れる電流が操作された場合、具体的には励磁コイル211,221,231がオフからオンに又はオンからオフに切り替えられた場合、共通接点21c,22c,23cの接続は、常閉接点21b,22b,23bに、又は常開接点21a,22a,23aに切り替わる。切り替わりが起きるときにインバータ4から電動機1への給電が続いていたとすると、切替器21,22,23の接点間にアーク放電が発生し、これにより接点溶着が発生する可能性がある。 When the electric current flowing through the excitation coils 211, 221, 231 is operated while the electric motor 1 is operating, that is, when the electric current is flowing through the switching devices 21, 22, and 23 constituting the wiring switching device 20, specifically, When the excitation coils 211, 221, 231 are switched from off to on or from on to off, the common contacts 21c, 22c, 23c are connected to normally closed contacts 21b, 22b, 23b, or normally open contacts 21a, 22a and 23a. If power continues to be supplied from the inverter 4 to the electric motor 1 when switching occurs, arc discharge may occur between the contacts of the switching devices 21, 22, and 23, which may cause contact welding.
 しかし、電動機1の回転速度をゼロにしてしまうと、再始動に必要なトルクが増加し、電動機1の起動時の電流が増加したり、電動機1が再起動することができなくなったりするおそれがある。例えば、電動機1が空気調和装置の圧縮機を負荷とする場合、圧縮機を駆動するために電動機1の回転速度をゼロにした直後は、冷媒の状態が安定していないため、再始動に必要なトルクが増加する。電動機1の回転速度をゼロにしてから、十分に冷媒の状態が安定するのに必要な時間が経過した後に、再始動を行うことも考えられる。その場合、圧縮機が冷媒を加圧することができなくなり、冷房能力又は暖房能力の低下により、室温の所望温度からの乖離が大きくなってしまうおそれがある。 However, if the rotational speed of the electric motor 1 is reduced to zero, the torque required for restarting will increase, and there is a risk that the current at the time of starting the electric motor 1 will increase or that the electric motor 1 will not be able to restart. be. For example, when the load of the electric motor 1 is the compressor of an air conditioner, immediately after the rotation speed of the electric motor 1 is reduced to zero to drive the compressor, the state of the refrigerant is not stable, so it is necessary to restart the refrigerant. torque increases. It is also conceivable to restart the electric motor 1 after the rotational speed of the electric motor 1 is reduced to zero and after a period of time necessary for the state of the refrigerant to become sufficiently stable has elapsed. In that case, the compressor will no longer be able to pressurize the refrigerant, and there is a risk that the room temperature will deviate from the desired temperature due to a decrease in cooling capacity or heating capacity.
 結線切替装置20に流れる電流がゼロとなるよう制御し、その状態で結線切替装置20に切り替え動作を行わせれば、切り替えの際に切替器21,22,23の接点間にアーク放電が発生することを防ぐことができる。このようにすれば、切り替えのために、電動機1の回転速度をゼロにする必要がなくなる。 If the current flowing through the connection switching device 20 is controlled to be zero and the connection switching device 20 is made to perform a switching operation in that state, arc discharge will occur between the contacts of the switching devices 21, 22, and 23 during switching. This can be prevented. In this way, there is no need to reduce the rotational speed of the electric motor 1 to zero for switching.
 結線切替装置20に流れる電流がゼロとなるようにするには、電動機1に流れる電流を検出してインバータ4のスイッチング動作により、電流がゼロとなるように制御する方法がある。又は、インバータ4のスイッチング動作を停止することにより電流を遮断する方法がある。又は、それら両方の方法を併用することにより、結線切替装置20に流れる電流がゼロとなることを実現することができる。 In order to make the current flowing through the connection switching device 20 zero, there is a method of detecting the current flowing through the motor 1 and controlling the current flowing to zero by the switching operation of the inverter 4. Alternatively, there is a method of cutting off the current by stopping the switching operation of the inverter 4. Alternatively, by using both of these methods in combination, it is possible to achieve zero current flowing through the connection switching device 20.
 図7は、実施の形態1における結線の切り替えが行われる際の制御シーケンスを説明するための図である。図7では、Y結線からΔ結線への切り替えが想定されている。図7(A)は、結線切替装置20に流れる電流を示している。図7(B)は、ゼロ選択信号Szのタイムチャートを示している。図7(C)は、結線選択信号Scのタイムチャートを示している。図7(D)は、二次磁束φdrの推定値と、誘起電圧定数φaとを示している。 FIG. 7 is a diagram for explaining a control sequence when wiring connections are switched in the first embodiment. In FIG. 7, switching from Y connection to Δ connection is assumed. FIG. 7(A) shows the current flowing through the connection switching device 20. FIG. 7(B) shows a time chart of the zero selection signal Sz. FIG. 7(C) shows a time chart of the connection selection signal Sc. FIG. 7(D) shows the estimated value of the secondary magnetic flux φdr and the induced voltage constant φa.
 ゼロ選択信号SzがLowを示す信号からHighを示す信号となる前に、制御部30は、切り替え前の二次磁束φdrを推定し、電動機1の減磁レベルを演算する。結線の切り替え後、電動機1に電流を再度通流する際の制御が安定するまでの制御応答の時定数と、二次磁束φdrの推定における収束速度とにより、結線の切り替え直後に二次磁束φdrを推定すると、誤った推定が行われるおそれがある。そこで、二次磁束φdrの推定値が安定した後に、すなわち、結線の切り替えが実施された時から予め設定された時間が経過した後に、制御部30は、二次磁束φdrを再度推定し、結線切替成否判定を行う。 Before the zero selection signal Sz changes from a signal indicating Low to a signal indicating High, the control unit 30 estimates the secondary magnetic flux φdr before switching and calculates the demagnetization level of the electric motor 1. After switching the wiring connection, the time constant of the control response until the control becomes stable when the current is passed through the motor 1 again, and the convergence speed in estimating the secondary magnetic flux φdr, the secondary magnetic flux φdr immediately after the switching of the wiring connection is determined. There is a risk that an incorrect estimate will be made. Therefore, after the estimated value of the secondary magnetic flux φdr becomes stable, that is, after a preset time has elapsed since the switching of the wiring connection, the control unit 30 estimates the secondary magnetic flux φdr again, and Determine the success or failure of switching.
 そのようにすることで、制御部30は、結線の切り替えが正常に行われたにもかかわらず切り替えが失敗したと判定すること、又は、切り替えが失敗したにも関わらず切り替えが正常に行われたと判定することを防止することができる。 By doing so, the control unit 30 can determine that the switching has failed even though the switching of the wiring has been performed normally, or that the switching has been performed normally even though the switching has failed. It is possible to prevent the determination that the
 なお、図7では、Y結線からΔ結線への切り替えが想定されているが、Δ結線からY結線への切り替えも同様に行われる。但し、Δ結線からY結線への切り替えが行われる場合、図7(C)の結線選択信号Scの内容は、LowからHighではなく、HighからLowに切り替わる。 Note that in FIG. 7, switching from Y connection to Δ connection is assumed, but switching from Δ connection to Y connection is also performed in the same way. However, when switching from Δ connection to Y connection is performed, the content of the connection selection signal Sc in FIG. 7(C) is not changed from Low to High, but from High to Low.
 上述のように、実施の形態1に係る駆動装置100が有する制御部30は、結線切替装置20により第1の結線が選択された後、切り替え前の二次磁束を推定し、切り替え前の二次磁束の推定値と第1の結線の状態における予め設定された誘起電圧定数とを比較することで減磁レベルを判定し、結線切替装置20により第2の結線への切り替えが行われた後、切り替え後の二次磁束を推定し、切り替え後の二次磁束の推定値と第2の結線の状態における予め設定された誘起電圧定数が減磁レベルに基づいて補正された値とを比較することで結線切替成否判定を行う。したがって、駆動装置100は、結線の切り替え後の二次磁束φdrの推定値と予め設定された結線の切り替え後の状態における誘起電圧定数φaを減磁レベルに基づいて補正された値とを比較することで、電動機1の減磁レベルによらず、結線切替成否判定を適切に行うことができる。 As described above, after the first connection is selected by the connection switching device 20, the control unit 30 included in the drive device 100 according to the first embodiment estimates the secondary magnetic flux before switching, and estimates the secondary magnetic flux before switching. After the demagnetization level is determined by comparing the estimated value of the secondary magnetic flux and the preset induced voltage constant in the state of the first connection, and the connection switching device 20 switches to the second connection. , estimate the secondary magnetic flux after switching, and compare the estimated value of the secondary magnetic flux after switching with a value in which a preset induced voltage constant in the state of the second connection is corrected based on the demagnetization level. This determines the success or failure of connection switching. Therefore, the drive device 100 compares the estimated value of the secondary magnetic flux φdr after switching the wiring connection with the preset value of the induced voltage constant φa in the state after switching the wiring connection, which is corrected based on the demagnetization level. Thus, regardless of the demagnetization level of the electric motor 1, it is possible to appropriately determine the success or failure of wiring connection switching.
実施の形態2.
 図8は、実施の形態2に係る空気調和装置200の構成を示す図である。空気調和装置200は、実施の形態1で説明された駆動装置100を有する。実施の形態2では、駆動装置100は、空気調和装置200が有する圧縮機904を駆動する電動機1を駆動する。つまり、空気調和装置200は、駆動装置100によって駆動される電動機1を有する。空気調和装置200は、電動機1を駆動源として冷凍サイクル900の冷媒を圧縮する圧縮機904を更に有する。
Embodiment 2.
FIG. 8 is a diagram showing the configuration of an air conditioner 200 according to the second embodiment. Air conditioner 200 includes drive device 100 described in Embodiment 1. In the second embodiment, drive device 100 drives electric motor 1 that drives compressor 904 included in air conditioner 200. That is, the air conditioner 200 has the electric motor 1 driven by the drive device 100. The air conditioner 200 further includes a compressor 904 that compresses the refrigerant of the refrigeration cycle 900 using the electric motor 1 as a drive source.
 冷凍サイクル900は、四方弁902の切り替え動作により暖房運転又は冷房運転を行うことができる。暖房運転時には、実線の矢印が示すように、冷媒は、圧縮機904で加圧されて送り出され、四方弁902、室内熱交換器906、膨張弁908、室外熱交換器910及び四方弁902を通って圧縮機904に戻る。冷房運転時には、破線の矢印が示すように、冷媒は、圧縮機904で加圧されて送り出され、四方弁902、室外熱交換器910、膨張弁908、室内熱交換器906及び四方弁902を通って圧縮機904に戻る。 The refrigeration cycle 900 can perform heating operation or cooling operation by switching the four-way valve 902. During heating operation, as shown by the solid arrow, the refrigerant is pressurized by the compressor 904 and sent out, and the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910, and the four-way valve 902 are compressed. and returns to the compressor 904. During cooling operation, as indicated by the dashed arrow, the refrigerant is pressurized by the compressor 904 and sent out, passing through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906, and the four-way valve 902. and returns to the compressor 904.
 交流電源2に接続された駆動装置100は可変速制御を行って電動機1を駆動し、電動機1は圧縮機904を駆動する。暖房運転時には、室内熱交換器906は凝縮器として機能し、室外熱交換器910は蒸発器として機能する。冷房運転時には、室外熱交換器910は凝縮器として機能し、室内熱交換器906は蒸発器として機能して熱を吸収する。膨張弁908は、冷媒を減圧して膨張させる。 The drive device 100 connected to the AC power source 2 performs variable speed control to drive the electric motor 1, and the electric motor 1 drives the compressor 904. During heating operation, indoor heat exchanger 906 functions as a condenser, and outdoor heat exchanger 910 functions as an evaporator. During cooling operation, the outdoor heat exchanger 910 functions as a condenser, and the indoor heat exchanger 906 functions as an evaporator to absorb heat. The expansion valve 908 reduces the pressure of the refrigerant and expands it.
 室内の温度調整の程度により、圧縮機904の圧力比が変動し、室内の設定温度と室内の実際の温度とが大きく離れている場合、駆動装置100は、電動機1の回転速度を大きくし、高圧縮状態を生じさせる。 The pressure ratio of the compressor 904 changes depending on the degree of indoor temperature adjustment, and if the indoor set temperature and the indoor actual temperature are significantly different, the drive device 100 increases the rotational speed of the electric motor 1, Creates a highly compressed state.
 上述のように、実施の形態2に係る空気調和装置200は、実施の形態1で説明された駆動装置100を有するので、圧縮機904を停止させずに、駆動状況に対応して電動機1の結線の切り替えを行うことができ、ひいては空気調和についての空調運転を継続することができる。すなわち、空気調和装置200は、ユーザの快適性を向上させることができる。また、結線切替成否判定が正しく行われるため、空気調和装置200は、結線の切り替えの異常時において駆動装置100が有するインバータ4を停止させることができ、結線が異常である状態での運転が継続することを防止することができる。 As described above, since the air conditioner 200 according to the second embodiment includes the drive device 100 described in the first embodiment, the electric motor 1 is activated in accordance with the driving situation without stopping the compressor 904. Connections can be switched, and air conditioning operation can be continued. That is, the air conditioner 200 can improve user comfort. In addition, since the connection switching success/failure determination is performed correctly, the air conditioner 200 can stop the inverter 4 included in the drive device 100 when the connection switching is abnormal, and the air conditioner 200 can continue to operate in a state where the connection is abnormal. This can be prevented.
 図9は、実施の形態1に係る駆動装置100が有する制御部30の一部又は全部がプロセッサ91によって実現される場合のプロセッサ91を示す図である。つまり、制御部30の一部又は全部の機能は、メモリ92に格納されるプログラムを実行するプロセッサ91によって実現されてもよい。プロセッサ91は、CPU(Central Processing Unit)、処理システム、演算システム、マイクロプロセッサ、又はDSP(Digital Signal Processor)である。図9には、メモリ92も示されている。 FIG. 9 is a diagram showing the processor 91 in a case where part or all of the control unit 30 included in the drive device 100 according to the first embodiment is implemented by the processor 91. That is, some or all of the functions of the control unit 30 may be realized by the processor 91 that executes a program stored in the memory 92. The processor 91 is a CPU (Central Processing Unit), a processing system, an arithmetic system, a microprocessor, or a DSP (Digital Signal Processor). A memory 92 is also shown in FIG.
 制御部30の一部又は全部の機能がプロセッサ91によって実現される場合、当該一部又は全部の機能は、プロセッサ91と、ソフトウェア、ファームウェア、又は、ソフトウェアとファームウェアとの組み合わせとによって実現される。ソフトウェア又はファームウェアは、プログラムとして記述され、メモリ92に格納される。プロセッサ91は、メモリ92に記憶されたプログラムを読み出して実行することにより、制御部30の一部又は全部の機能を実現する。 When some or all of the functions of the control unit 30 are realized by the processor 91, some or all of the functions are realized by the processor 91, software, firmware, or a combination of software and firmware. Software or firmware is written as a program and stored in memory 92. The processor 91 implements some or all of the functions of the control unit 30 by reading and executing programs stored in the memory 92 .
 制御部30の一部又は全部の機能がプロセッサ91によって実現される場合、駆動装置100は、制御部30によって実行されるステップの一部又は全部が結果的に実行されることになるプログラムを格納するためのメモリ92を有する。メモリ92に格納されるプログラムは、制御部30が実行する手順又は方法の少なくとも一部をコンピュータに実行させるものであるともいえる。 When some or all of the functions of the control unit 30 are realized by the processor 91, the drive device 100 stores a program that results in some or all of the steps executed by the control unit 30. It has a memory 92 for storing data. It can be said that the program stored in the memory 92 causes the computer to execute at least part of the procedure or method executed by the control unit 30.
 メモリ92は、例えば、RAM(Random Access Memory)、ROM(Read Only Memory)、フラッシュメモリ、EPROM(Erasable Programmable Read Only Memory)、EEPROM(登録商標)(Electrically Erasable Programmable Read-Only Memory)等の不揮発性若しくは揮発性の半導体メモリ、磁気ディスク、フレキシブルディスク、光ディスク、コンパクトディスク、ミニディスク又はDVD(Digital Versatile Disk)等である。 The memory 92 is, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (registered trademark) (Electrically Erasable Programmable Read-Only Memory). ) etc. non-volatile Alternatively, it may be a volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD (Digital Versatile Disk), or the like.
 図10は、実施の形態1に係る駆動装置100が有する制御部30の一部又は全部が処理回路93によって実現される場合の処理回路93を示す図である。つまり、制御部30の一部又は全部は、処理回路93によって実現されてもよい。 FIG. 10 is a diagram showing a processing circuit 93 in a case where part or all of the control unit 30 included in the drive device 100 according to the first embodiment is implemented by the processing circuit 93. That is, part or all of the control unit 30 may be realized by the processing circuit 93.
 処理回路93は、専用のハードウェアである。処理回路93は、例えば、単一回路、複合回路、プログラム化されたプロセッサ、並列プログラム化されたプロセッサ、ASIC(Application Specific Integrated Circuit)、FPGA(Field-Programmable Gate Array)、又はこれらを組み合わせたものである。 The processing circuit 93 is dedicated hardware. The processing circuit 93 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. It is.
 制御部30の一部は、制御部30の残部とは別個の専用のハードウェアによって実現されてもよい。 A part of the control unit 30 may be realized by dedicated hardware separate from the rest of the control unit 30.
 制御部30の複数の機能について、当該複数の機能の一部がソフトウェア又はファームウェアで実現され、当該複数の機能の残部が専用のハードウェアで実現されてもよい。このように、制御部30の複数の機能は、ハードウェア、ソフトウェア、ファームウェア、又はこれらの組み合わせによって実現することができる。 Regarding the plurality of functions of the control unit 30, some of the plurality of functions may be realized by software or firmware, and the remainder of the plurality of functions may be realized by dedicated hardware. In this way, the plurality of functions of the control unit 30 can be realized by hardware, software, firmware, or a combination thereof.
 以上の実施の形態に示した構成は、一例を示すものであり、別の公知の技術と組み合わせることも可能であるし、要旨を逸脱しない範囲で、構成の一部を省略又は変更することも可能である。 The configurations shown in the above embodiments are merely examples, and can be combined with other known techniques, or a part of the configuration can be omitted or changed without departing from the scope of the invention. It is possible.
 1 電動機、2 交流電源、3 コンバータ、4 インバータ、5 負荷、6a,6b 検出部、20 結線切替装置、21,22,23 切替器、21a,22a,23a 常開接点、21b,22b,23b 常閉接点、21c,22c,23c 共通接点、24 中性点ノード、25 電源、30 制御部、31 運転指令部、32 インバータ制御部、41,42,43 巻線、41a,42a,43a 第1の端部、41b,42b,43b 第2の端部、41c,41d,42c,42d,43c,43d 外部端子、91 プロセッサ、92 メモリ、93 処理回路、100 駆動装置、200 空気調和装置、204 半導体スイッチ、211,221,231 励磁コイル、900 冷凍サイクル、902 四方弁、904 圧縮機、906 室内熱交換器、908 膨張弁、910 室外熱交換器。 1 Electric motor, 2 AC power supply, 3 Converter, 4 Inverter, 5 Load, 6a, 6b Detector, 20 Connection switching device, 21, 22, 23 Switch, 21a, 22a, 23a Normally open contact, 21b, 22b, 23b Normally Closed contact, 21c, 22c, 23c common contact, 24 neutral node, 25 power supply, 30 control unit, 31 operation command unit, 32 inverter control unit, 41, 42, 43 winding, 41a, 42a, 43a first End, 41b, 42b, 43b Second end, 41c, 41d, 42c, 42d, 43c, 43d External terminal, 91 Processor, 92 Memory, 93 Processing circuit, 100 Drive device, 200 Air conditioner, 204 Semiconductor switch , 211, 221, 231 Excitation coil, 900 Refrigeration cycle, 902 Four-way valve, 904 Compressor, 906 Indoor heat exchanger, 908 Expansion valve, 910 Outdoor heat exchanger.

Claims (6)

  1.  交流電源から供給された交流電圧を整流するコンバータと、
     前記コンバータによって得られた整流電圧から設定回転速度に対応する交流電圧を生成して電動機に供給するインバータと、
     切り替え指令にしたがって前記電動機の巻線の結線状態を切り替える結線切替装置と、
     前記電動機の負荷電流を検出する検出部と、
     前記インバータ及び前記結線切替装置を制御する制御部とを備え、
     前記制御部は、前記結線切替装置により第1の結線が選択された後、切り替え前の二次磁束を推定し、前記切り替え前の二次磁束の推定値と前記第1の結線の状態における予め設定された誘起電圧定数とを比較することで減磁レベルを判定し、前記結線切替装置により第2の結線への切り替えが行われた後、切り替え後の二次磁束を推定し、前記切り替え後の二次磁束の推定値と前記第2の結線の状態における予め設定された誘起電圧定数が前記減磁レベルに基づいて補正された値とを比較することで結線切替成否判定を行う
     駆動装置。
    A converter that rectifies AC voltage supplied from an AC power supply;
    an inverter that generates an alternating current voltage corresponding to a set rotational speed from the rectified voltage obtained by the converter and supplies the generated alternating current voltage to the electric motor;
    a connection switching device that switches the connection state of the windings of the motor according to a switching command;
    a detection unit that detects a load current of the electric motor;
    comprising a control unit that controls the inverter and the connection switching device,
    After the first connection is selected by the connection switching device, the control unit estimates the secondary magnetic flux before switching, and calculates the estimated value of the secondary magnetic flux before switching and the predetermined value in the state of the first connection. The demagnetization level is determined by comparing it with the set induced voltage constant, and after switching to the second connection is performed by the connection switching device, the secondary magnetic flux after switching is estimated, and the secondary magnetic flux after the switching is determined. A drive device in which connection switching success or failure is determined by comparing an estimated value of secondary magnetic flux of the second connection state with a value obtained by correcting a preset induced voltage constant based on the demagnetization level in the second connection state.
  2.  前記制御部は、下記の式の補正演算結果と判定値とに基づいて前記結線切替成否判定を行う
     (二次磁束の推定値)-(誘起電圧定数×減磁レベル値(%)/100)
     請求項1に記載の駆動装置。
    The control unit determines the success or failure of the connection switching based on the correction calculation result and determination value of the following formula (estimated value of secondary magnetic flux) - (induced voltage constant x demagnetization level value (%) / 100)
    The drive device according to claim 1.
  3.  前記制御部は、前記結線切替成否判定を行う場合、前記切り替え後の二次磁束の推定値と前記第2の結線の状態における予め設定された誘起電圧定数が前記減磁レベルに基づいて補正された値とを比較するとき、判定値に正負の尤度を持たせて前記結線切替成否判定を行う
     請求項1又は2に記載の駆動装置。
    When determining the success or failure of the connection switching, the control unit corrects the estimated value of the secondary magnetic flux after the switching and a preset induced voltage constant in the state of the second connection based on the demagnetization level. The drive device according to claim 1 or 2, wherein when comparing the determined value, the determination value is given a positive or negative likelihood to determine the success or failure of the connection switching.
  4.  前記制御部は、前記結線切替成否判定の結果、切替状態が異常であると判断した場合、前記電動機を停止させる動作を行う
     請求項1から3のいずれか1項に記載の駆動装置。
    The drive device according to any one of claims 1 to 3, wherein the control unit performs an operation to stop the electric motor when determining that the switching state is abnormal as a result of the connection switching success/failure determination.
  5.  前記制御部は、結線の切り替えが実施された時から予め設定された時間が経過した後に前記結線切替成否判定を行う
     請求項1から4のいずれか1項に記載の駆動装置。
    The drive device according to any one of claims 1 to 4, wherein the control unit determines the success or failure of the connection switching after a preset time has elapsed since the connection switching was performed.
  6.  請求項1から5のいずれか1項に記載の駆動装置によって駆動される電動機と、
     前記電動機を駆動源として冷凍サイクルの冷媒を圧縮する圧縮機と
     を備える空気調和装置。
    An electric motor driven by the drive device according to any one of claims 1 to 5,
    and a compressor that compresses refrigerant in a refrigeration cycle using the electric motor as a drive source.
PCT/JP2022/012596 2022-03-18 2022-03-18 Drive device and air conditioning device WO2023175893A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008148490A (en) * 2006-12-12 2008-06-26 Toshiba Corp Rotary machine drive system, washing machine, and winding switching result confirmation method for rotary machine
WO2019008756A1 (en) * 2017-07-07 2019-01-10 三菱電機株式会社 Motor drive system and air conditioner
WO2019021373A1 (en) * 2017-07-25 2019-01-31 三菱電機株式会社 Drive device, compressor, air conditioner, and drive method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008148490A (en) * 2006-12-12 2008-06-26 Toshiba Corp Rotary machine drive system, washing machine, and winding switching result confirmation method for rotary machine
WO2019008756A1 (en) * 2017-07-07 2019-01-10 三菱電機株式会社 Motor drive system and air conditioner
WO2019021373A1 (en) * 2017-07-25 2019-01-31 三菱電機株式会社 Drive device, compressor, air conditioner, and drive method

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