JP2013093988A - Motor drive unit and vacuum cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and light weight motor drive unit independent from the power supply conditions at a low cost.SOLUTION: A motor drive unit 20 includes: an inverter circuit 22 that receives an AC power 1 from the outside and converts the same into a power with a desired frequency to drive a motor 8 externally connected thereto; a storage battery 14 connected to the I/O side of the inverter circuit 22; and a control unit 15 having control functions that, when driving the motor 8, drives the motor 8 through the inverter circuit 22 by using the power from the storage battery 14 or a power from an external AC power 1; and when charging the storage battery 14, outputs a DC power to one phase of the outputs in the inverter circuit 22 to charge the storage battery 14 using the DC power. The motor drive unit 20 which is small and light weight and independent from the power supply conditions can be achieved at a low cost.

Description

  The present invention relates to an AC power source or a motor driving device that converts electric power from a DC power source of a storage battery into alternating current of a desired frequency and drives a motor as a load, and a vacuum cleaner using the motor driving device.

  As a device that has the function of driving the electric motor with the electric power of the storage battery provided inside while driving the electric motor with the electric power from the conventional external AC power source, the output of the generator is converted into alternating current with an inverter, and the compressor motor is installed. In addition to driving, the internal storage battery is charged by the output of the generator using a charging circuit, and when the output of the generator is reduced, the compressor motor is driven using the power of the storage battery to provide a stable refrigerating capacity. An realized refrigeration apparatus for a refrigerator car has been devised (see, for example, Patent Document 1).

  In this refrigeration vehicle refrigeration apparatus, a storage battery unit including a charging circuit and a storage battery is provided between a rectifier circuit and a switching circuit of an inverter, and charging is performed by supplying a constant voltage to the storage battery by the charging circuit.

  In addition, when a power outage is not permitted during a power failure or when driving an AC motor that is started up as emergency power during a power outage, a storage battery is installed as a backup power source. There has been proposed an AC motor drive device that drives an AC motor by using (see, for example, Patent Document 2).

  In this AC motor drive device, a charger and a charge control circuit connected to an AC power source are provided, and the storage battery is charged using the charger, and when a power failure occurs, the power charged in the storage battery is boosted by a boost chopper. The AC motor can be operated by supplying power to the AC motor via the inverter.

JP 2001-56170 A JP 2010-154650 A

  In such a motor drive device, when charging a storage battery as an emergency power supply, the power from the external power supply is controlled to a voltage that can be charged by a step-down chopper circuit or the like, and the current flowing through the storage battery is controlled to a chargeable current. There is a need for a charging circuit having the function of: This charging circuit is composed of a coil for step-down voltage, a switching element, a control IC, and the like, but both the cost and size are large, which is a major factor in increasing the cost and size of the entire apparatus.

  The present invention has been made in view of such a point, and the object of the present invention is to install a storage battery, and to reduce the power stored in the storage battery when a power failure occurs or when the input power of the external power source decreases. In a motor drive device that uses a motor to drive the battery, the storage battery is charged by using an inverter provided in the motor drive device. The purpose is to realize an electric vacuum cleaner that uses the.

  A motor driving device according to the present invention is connected to an inverter circuit that drives an externally connected motor by converting the power of the external power source into power of an arbitrary frequency by using a DC external power source as input, and is connected to the input / output side of the inverter circuit. When driving the storage battery and the motor, the motor is driven by the inverter circuit using the power of the storage battery or the power of the external power source, and when the storage battery is charged, DC power is output to one phase of the output of the inverter circuit. And a control unit having a control function of charging the storage battery using DC power.

  As a result, a motor drive device that is resistant to a power supply environment, which is constituted by a small, lightweight, and low-cost circuit using a DC external power supply as an input, is realized.

  As described above, according to the present invention, a motor driving device that is configured with a small, light, and low-cost circuit and is strong in a power supply environment, and a vacuum cleaner using the motor driving device are realized.

1 is a circuit configuration diagram showing the overall configuration of a motor drive device according to Embodiment 1 of the present invention. The flowchart showing the operation of the control means of the motor drive device The same state diagram showing the transition of switching during motor drive in the inverter circuit of the motor drive device The same, the state diagram which shows the transition of switching at the time of storage battery charge with the inverter circuit in the motor drive device FIG. 3 is a circuit configuration diagram showing an overall configuration of a motor drive device according to a second embodiment of the present invention. The same state diagram showing the transition of switching during motor drive in the inverter circuit of the motor drive device The same, the state diagram which shows the transition of switching at the time of storage battery charge with the inverter circuit in the motor drive device The block diagram which shows the main structures of the vacuum cleaner which concerns on Embodiment 3 of this invention.

According to a first aspect of the present invention, there is provided an inverter circuit for driving a motor externally connected by converting a power of an external power source into a power of an arbitrary frequency with a DC external power source as an input, and a storage battery connected to an input / output side of the inverter circuit; When the motor is driven, the motor is driven by the inverter circuit using the power of the storage battery or the power of the external power source. At the time of charging the storage battery, DC power is output to one phase of the output of the inverter circuit. And a control means having a control function for charging the storage battery.
As a result, a motor drive device that is resistant to a power supply environment, which is constituted by a small, lightweight, and low-cost circuit using a DC external power supply as an input, is realized.

According to a second aspect of the present invention, there is provided a converter for converting an external power supply into a direct current with an AC external power supply as an input, and an inverter for driving an externally connected motor by converting the power output from the converter into an arbitrary frequency power. When the motor is driven, the motor is driven by the inverter circuit using the power of the storage battery or the power of the external power source, and when the battery is charged, the output of the inverter circuit Control means having a control function of outputting DC power to one phase of the battery and charging the storage battery using the DC power.
As a result, a motor drive device that is resistant to a power supply environment that is constituted by a small, lightweight, and low-cost circuit using an AC external power supply as an input is realized.

According to a third aspect of the invention, in particular, the inverter circuit according to the first or second aspect of the invention includes a switching element for three phases, with two switching elements connected in series as one phase, and when the motor is driven, By switching the switching element for 3 minutes, the power of 3 phases is output and the motor of 3 phases is driven. When charging the storage battery, the switching circuit for 1 phase is switched among the switching elements for 3 phases of the inverter circuit. And control means for performing control to output DC power by switching only the elements.
As a result, a motor drive device that is configured with a small, light, and low-cost circuit and that has a function of driving a three-phase motor and is resistant to a power supply environment is realized.

According to a fourth aspect of the present invention, in particular, the inverter circuit of the first or second aspect of the invention includes two switching elements for one phase, and the control means is configured to output 2 at the time of driving the motor. By switching the phase switching elements, two-phase arbitrary frequency power is output to drive the two-phase motor, and when charging the storage battery, one of the two-phase switching elements of the inverter circuit is 1 Control is performed to output DC power by switching only the switching elements for the phase.
As a result, a motor drive device that is configured with a small, light, and low-cost circuit and that has a function of driving a two-phase motor and is resistant to a power supply environment is realized.

According to a fifth invention, in particular, in the third or fourth invention, a first switch is provided between an input side of the storage battery and the inverter circuit, and a second switch is provided between the output side of the storage battery and the inverter circuit. A switch is provided, and the control means performs control to turn on the first switch when driving the motor with the power of the storage battery and to turn on the second switch when charging the storage battery with the power from an external power source. Means.
This realizes a motor drive device that is configured with a small, light, and low-cost circuit and that is resistant to a power supply environment in which motor drive and storage battery charging can be easily switched.

In a sixth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the input side of the inverter circuit includes voltage detection means for detecting the voltage of the input section, and the detected voltage is a predetermined value. In the following cases, the motor is driven by the power of the storage battery, and when the detected voltage is equal to or higher than a predetermined value, the motor is driven by the power of the external power source or the control means for controlling the storage battery is provided. It is.
As a result, a motor drive device that is configured with a small, light, and low-cost circuit and that is excellent in safety and in which the external power supply drive and the storage battery drive are automatically switched is realized.

According to a seventh aspect of the invention, in particular, in any one of the second to fifth aspects of the invention, the input side from the external power source of the converter is provided with voltage detection means for detecting an input voltage, and the detected voltage is predetermined. When the detected voltage is equal to or higher than a predetermined value, the motor is driven by the electric power from the external power source or the control means for controlling the charging of the storage battery is provided. It is a thing.
As a result, a motor drive device that is composed of a small, light, and low-cost circuit and that functions with an AC power supply input. The motor drive device that is resistant to a power supply environment that automatically switches between external power supply drive and storage battery drive. Is realized.

In an eighth aspect of the invention, in particular, in any one of the first to seventh aspects, a booster circuit connected to the input side of the inverter circuit is provided, and the output of the storage battery is connected to the input side of the booster circuit. is there.
As a result, a motor drive device that is configured with a small, light, and low-cost circuit and that can secure the motor drive voltage regardless of the power supply environment is realized.

According to a ninth aspect of the invention, in particular, in the eighth aspect of the invention, the input side of the booster circuit is provided with voltage detection means for detecting the voltage of the input unit, and when the detected voltage is not more than a predetermined value, the power of the storage battery And a control means for controlling the driving of the motor with the power of the external power source or the charging of the storage battery when the detected voltage is equal to or higher than a predetermined value.
As a result, a small, lightweight, low-cost circuit is realized, a motor drive voltage can be secured regardless of the power supply environment, and a motor drive device with excellent safety that automatically switches between an external power supply and a storage battery power supply is realized. The

In a tenth aspect of the invention, in particular, in any one of the second to ninth aspects of the invention, a third switch is provided on an input side from an external power source, and the control means is a motor using electric power from the external power source. The third switch is turned on when driving the battery or charging the storage battery.
As a result, a small, lightweight, low-cost circuit is realized, a motor drive voltage can be secured regardless of the power supply environment, and a motor drive device with excellent safety that automatically switches between an external power supply and a storage battery power supply is realized. The

The eleventh aspect of the invention is characterized in that the fan motor drive device is constituted by the motor drive device of any one of the first to tenth inventions.
This realizes a small and low-cost vacuum cleaner that can stably drive the fan motor and obtain the vacuum cleaner function regardless of the power supply environment, either by the external AC power supply or by the power of the internal storage battery. It is.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit configuration diagram showing the overall configuration of the motor drive device 20 according to the first embodiment of the present invention.
The AC power supplied from the AC power source 1 is a rectifier circuit 9 composed of a full-wave rectifier diode bridge through an AC voltage detecting means 19 for detecting the voltage of the AC power and an AC switch 18 for turning on / off the connection of the AC power source. Is converted to direct current.

  The DC power converted by the rectifier circuit 9 is boosted by a booster circuit 21 which is a general booster chopper circuit composed of a booster coil 10, a boosting switching element 12, a diode 11, and a smoothing capacitor 13. For example, when the input of the AC power supply 1 is AC100V, the output of the rectifier circuit 9 becomes a fluctuation voltage of about 0V to 140V, but is boosted to an arbitrary smoothed DC voltage of about 140V to 300V by the booster circuit 21, for example. be able to.

  The DC power boosted by the booster circuit 21 is input to an inverter circuit 22 composed of switching elements 2a to 7a and switching circuits 2 to 7 composed of diodes 2b to 7b connected in parallel thereto. In the inverter circuit 22, it is converted into alternating current of an arbitrary frequency and supplied to the motor 8 connected to the interconnection point of the switching circuits 2, 4, 6 on the upper arm side and the switching circuits 3, 5, 7 on the lower arm side. Is done. As a result, the motor 8 can be driven at an arbitrary rotational speed.

  The control means 15 controls the switching of the switching elements 2a to 7a so that the inverter circuit 22 outputs AC power that causes the motor 8 to rotate at a desired rotational speed. As a switching method, a general pulse width modulation (PWM) method in which the output voltage is controlled by the time width of the drive pulse of the element is used.

  Furthermore, a storage battery 14 is provided in the motor drive device 20, and one end thereof is connected to a connection point between the rectifier circuit 9 and the booster circuit 21 through the discharge switch 16. Further, the other end is connected to the one-phase power line of the three-phase power lines connected from the inverter circuit 22 to the motor 8 through the charging switch 17.

  The electric power for driving the motor 8 can use electric power from the AC power source 1 and can also use electric power from the storage battery 14. When the power from the AC power source 1 is used, the AC side switch 18 is set to ON and the discharge switch 16 is set to OFF. When the power from the storage battery 14 is used, the AC side switch 18 is set to OFF. 16 is set to ON.

  Accordingly, when using power from the AC power source 1, power from the AC power source 1 is supplied to the input terminal of the booster circuit 21, and when using power from the storage battery 14, the power of the storage battery 14 is used. Is supplied to the input terminal of the booster circuit 21 to drive the motor 8. The control means 15 switches the power to be used by controlling the AC side switch 18 and the discharge switch 16.

  Further, at the time of charging, the AC side switch 18 is turned on, the discharge switch 16 is turned off, and the charge switch 17 is turned on. As a result, power from the AC power source 1 is input to the inverter circuit 22 through the booster circuit 21, and DC power output from one phase of the three-phase output of the inverter circuit 22 is supplied to the storage battery 14 and charged. .

  Next, the operation mode switching control function in the control means 15 will be described. FIG. 2 is a flowchart showing the operation of the control means 15 of the motor drive device according to the first embodiment. This motor drive device has a mode for driving a motor or a mode for charging a storage battery. The mode is set to charge the storage battery 14 except when the motor is driven by a user operation.

  When the mode is determined in step S101, in the case of the motor drive mode, in step S102, the value of the AC voltage detected by the AC voltage detecting means 19 for detecting the voltage of the AC power is input and the value of the AC voltage is obtained. Is greater than a predetermined voltage value (voltage A), it is determined that power is supplied from the external power source. Conversely, if the voltage is equal to or lower than the predetermined voltage value (voltage A), power is supplied from the external power source. Is determined not to be supplied. The predetermined voltage value is set to the lowest voltage value that can drive the motor.

  If it is determined that power is supplied from the external power supply, in step 104, the AC side switch 18 is turned on, the discharge switch 16 is turned off, and the charge switch 17 is turned off. As a result, power from the AC power supply 1 is supplied to the input terminal of the booster circuit 21 and further supplied to the inverter circuit 22, thereby driving the motor 8.

  On the other hand, if it is determined that no power is supplied from the external power supply, in step 105, the AC side switch 18 is turned off, the discharge switch 16 is turned on, and the charge switch 17 is turned off. Thereby, the electric power of the storage battery 14 is supplied to the input terminal of the booster circuit 21 and further supplied to the inverter circuit 22, thereby driving the motor 8. Thereafter, in step 106, the motor is driven by controlling the switching elements 2a to 7a so as to output the three-phase alternating current from the inverter circuit 22.

On the other hand, the mode is determined in step S101, and in the case of the storage battery charging mode, in step S107, the AC side switch 18 is turned on, the discharge switch 16 is turned off, and the charge switch 17 is turned on. As a result, the power from the AC power source 1 is supplied to the input terminal of the booster circuit 21 and further supplied to the inverter circuit 22, and the DC power output from one phase of the three-phase outputs of the inverter circuit 22 is stored in the storage battery. 14 is provided. Thereafter, in step 108, the storage battery 14 is charged by controlling the switching elements 2a to 7a so as to output DC power from the inverter circuit 22.

  FIG. 3 is a state diagram showing a transition of switching during motor driving of the inverter circuit 22 of the motor driving device 20 according to the first embodiment of the present invention. Switching of the switching elements 2a to 7a is controlled by the control means 15 so that the inverter circuit 22 that drives the motor 8 outputs a three-phase alternating current. As a switching method, a PWM (Pulse Width Modulation) method for controlling an output voltage with a pulse width is used. As a carrier wave in the PWM system, a triangular wave having a period of Tc and an amplitude of Vc is used, and the switching timing of the switching elements 2a to 7a is determined by comparison with the output AC three-phase voltage.

  When the three-phase alternating current of the inverter circuit 22 is changed to the U-phase, V-phase, and W-phase, the switching elements 2a and 3a corresponding to the output voltage of the U-phase have the time t0 to t5 as shown in FIG. Switching is performed so that the switching element 2a is turned on and the switching element 3a is turned off. As a result, a voltage that is the same as the U-phase output voltage to be output and the average voltage is output from the U-phase, which is one of the three-phase AC outputs of the inverter circuit 22. Similarly, the switching elements 4a and 5a corresponding to the V-phase output voltage are switched so that the switching element 4a is turned on and the switching element 5a is turned off between times t1 and t4 as shown in FIG. .

  The switching elements 6a and 7a corresponding to the W-phase output voltage are switched so that the switching element 6a is turned on and the switching element 7a is turned off between times t2 and t3 as shown in FIG. Thereby, a three-phase alternating current output is output from the inverter circuit 22, and the connected motor 8 is driven.

  FIG. 4 is a state diagram showing the transition of switching during charging of the storage battery of the inverter circuit 22 of the motor drive device 20 according to the first embodiment of the present invention. The three-phase AC output of the inverter circuit 22 is U-phase, V-phase, and W-phase, the phase corresponding to the switching elements 2a and 3a is U-phase, the phase corresponding to the switching elements 4a and 5a is V-phase, and the switching element When the phase corresponding to 6a and 7a is the W phase, the V-phase output of the inverter circuit 22 is supplied to the storage battery 14 through the charging switch 17 set to ON during charging. For this purpose, the switching element 2a, 3a corresponding to the U-phase is switched to lower the voltage using the inductance of the motor 8. Thereby, charging voltage control by configuring a step-down chopper circuit by the inverter circuit 22 becomes possible.

  Of the three-phase AC outputs of the U-phase, V-phase, and W-phase of the inverter circuit 22, only the switching elements 2a and 3a corresponding to the U-phase are switched. With respect to the charging voltage for charging the storage battery 14, the switching elements 2a and 3a are switched so that the switching element 2a is on and the switching element 3a is off between times t6 and t7 as shown in FIG.

  In other sections within the same carrier period, switching is performed such that the switching element 2a opposite to that is turned off and the switching element 3a is turned on. The switching elements 4a to 7a corresponding to the other V and W phases are always set to off.

As a result, a voltage that is the same as the charging voltage to be output and the average voltage is output from the V phase or the W phase, which is a different phase from the U phase in the three-phase AC output of the inverter circuit 22. In the present embodiment, the storage battery 14 passes through the charging switch 17 in which the output from the V phase is set to ON.
To be supplied. It goes without saying that the charging voltage value for charging the storage battery 14 may be set to an optimum voltage value for the storage battery 14 and set to a voltage value for realizing a predetermined charging current.

  As described above, in the motor drive device according to the first embodiment, AC power supplied from the AC power supply 1 is converted into DC power by the rectifier circuit 9, boosted by the booster circuit 21, and then input to the inverter circuit 22. Then, the motor 8 is driven at an arbitrary number of revolutions by being converted into alternating current of an arbitrary frequency and supplied to the connected motor 8.

  Furthermore, the electric power of the storage battery 14 provided in the motor drive device 20 is output to the booster circuit 21 through the discharge switch 16 and supplied to the inverter circuit 22, whereby the motor 8 is driven by the electric power of the storage battery. In addition, the storage battery 14 is charged with DC power output from the inverter circuit 22 to a one-phase power line among the three-phase power lines connected to the motor 8.

  As a result, a motor drive device that can stably drive a three-phase motor with an external AC power source or with the power of an internal storage battery in a small, low-cost circuit is realized.

(Embodiment 2)
FIG. 5 is a circuit configuration diagram showing the overall configuration of the motor drive device 47 according to the second embodiment of the present invention. As the motor 40 driven by the motor drive device 47, a two-phase SR (Switched Reluctance) motor or the like is used. The SR motor drive device is composed of an inverter circuit 48 in which each phase switching circuit is independent.

  AC power supplied from the AC power supply 31 is converted into DC by a rectifier circuit 41 formed of a diode bridge for full-wave rectification. The direct current power converted by the rectifier circuit 41 is connected to switching elements 32a to 35a composed of switching elements 32a to 35a and diodes 32b to 35b connected in parallel to the direct current part to which the smoothing capacitor 42 is connected. Furthermore, it is input to an inverter circuit 48 constituted by diodes 36 to 39 connected in series with switching elements 32a to 35a between terminals of the DC part.

  The motor 40 has two windings (X phase and Y phase), and the inverter circuit 48 includes two sets of switching circuits corresponding thereto. In the inverter circuit 48, the input DC power is converted into a pulse current having an arbitrary frequency and supplied to the motor 40 connected to the interconnection point of the switching elements 32 a to 35 a and the diodes 36 to 39. 40 can be driven at an arbitrary rotational speed.

  Further, a storage battery 43 is provided in the motor drive device 47, and one end thereof is connected to a connection point between the rectifier circuit 41 and the inverter circuit 22 at the cathode end of the diode 54 through the discharge switch 45 and the diode 54. Further, the other end is connected to one of the four two-phase power lines connected from the inverter circuit 48 to the motor 40 through the charging switch 46.

The electric power for driving the motor 40 can use electric power from the AC power source 31 and can also use electric power from the storage battery 43. When the power from the AC power supply 31 is used, the discharge switch 45 and the charge switch 46 are set to off. When the power from the storage battery 43 is used, the discharge switch 45 is on and the charge switch 46 is off. Is set. As a result, when power from the AC power supply 31 is used, power from the AC power supply 31 is supplied to the input terminal of the inverter circuit 22, and when power from the storage battery 43 is used, the power of the storage battery 43 is used. Is supplied to the input terminal of the inverter circuit 22 so that the motor 40 is driven. The control means 44 performs switching of the electric power to be used by controlling the discharge switch 45 and the charge switch 46.

  Further, at the time of charging, the discharge switch 45 is set off and the charge switch 46 is set on. As a result, power from the AC power supply 31 is input to the inverter circuit 48, and DC power output from one phase of the two-phase outputs of the inverter circuit 48 is supplied to the storage battery 43 and charged.

  Further, voltage detection means 49 is provided at the input end of the inverter circuit 48 to detect the voltage of the DC section. When the voltage value exceeds the predetermined voltage value, it is determined that power is supplied from the AC power supply 31, and conversely, when the voltage value is equal to or lower than the predetermined voltage value, power is supplied from the AC power supply. It is judged that it is not. The predetermined voltage value is set to the lowest voltage value that can drive the motor.

  When it is determined that electric power is supplied from the AC power supply, the discharge switch 45 is set off and the charge switch 46 is set off. Thus, the electric power from the AC power supply 31 is supplied to the input terminal of the inverter circuit 48, so that the motor 40 is driven. Further, when charging, the discharge switch 45 is turned off and the charge switch 46 is turned on, so that power from the AC power supply 31 is supplied to the input terminal of the inverter circuit 48 to charge the storage battery 43. It becomes composition.

  Conversely, when it is determined that power is not supplied from the AC power supply, the discharge switch 45 is set on and the charge switch 46 is set off. As a result, the electric power of the storage battery 43 is supplied to the inverter circuit 22 to drive the motor 40.

  The control means 44 controls the switching of the switching elements 32a to 35a so that the inverter circuit 48 outputs power that causes the motor 40 to rotate at a desired rotational speed. As a switching method, control is performed by a method of generating a drive pulse of the element so that the motor current flows in synchronization with the rotation angle of the motor 40.

  FIG. 6 is a state diagram showing a transition of switching during motor driving of the inverter circuit 48 of the motor driving device 47 according to the second embodiment of the present invention. The switching elements 32a to 35a are performed so that the inverter circuit 48 that drives the motor 40 outputs two-phase power. For example, the switching elements 32a and 33a are switched at a predetermined conduction rate during a period from time t20 to t21, and the switching elements 34a and 35a are switched at a certain conduction ratio during a period from time t22 to t23. . As a result, current flows alternately through the two-phase windings (X-phase winding and Y-phase winding) of the motor 40 at a constant cycle, whereby the motor 40 is driven in accordance with the cycle. This control is controlled by the control means 44.

  FIG. 7 is a state diagram showing the transition of switching during charging of the storage battery of the inverter circuit 48 of the motor drive device 47 according to the second embodiment of the present invention. At the time of charging, the output of one end of the X phase of the inverter circuit 48 is supplied to the storage battery 43 through the charging switch 46 set to ON. For this purpose, the voltage is dropped using the inductance of the motor 40 by switching the switching element 32a corresponding to the X phase. As a result, the charging voltage can be controlled by configuring the step-down chopper circuit by the inverter circuit 48.

Of the two-phase outputs of the X-phase and Y-phase of the inverter circuit 48, only the switching element 32a corresponding to the X-phase is switched. With respect to the charging voltage for charging the storage battery 43, the switching element 32a is switched so that the switching element 32a is turned on between times t10 and t11 as shown in FIG. Moreover, it sets so that the switching element 32a may be turned off between the time t11-t12. The other switching elements 33a to 35a are always set to off.

  As a result, a voltage that is the same as the charging voltage to be output and the average voltage is output from one end of the X phase in the output of the inverter circuit 48, and a predetermined charging current is supplied. Further, it is supplied to the storage battery 43 through the charging switch 46 set to ON. It goes without saying that the charging voltage value for charging the storage battery 43 may be set to an optimum voltage value for the storage battery 43 and set to a voltage value for realizing a predetermined charging current.

  As described above, in the motor drive device according to the second embodiment, the AC power supplied from the AC power supply 31 is converted into DC power by the rectifier circuit 41, input to the inverter circuit 48, and converted to power of an arbitrary frequency. And supplied to the connected motor 40. As a result, the motor 40 is driven at an arbitrary rotational speed. Furthermore, the electric power of the storage battery 43 provided in the motor driving device 47 is supplied to the inverter circuit 48 through the discharge switch 45 and the diode 54, so that the motor 40 is also driven by the electric power of the storage battery 43.

  In addition, the storage battery 43 is charged by DC power output from the inverter circuit 48 to the one-phase power line of the two-phase power lines connected to the motor 40. As a result, a motor driving device that can stably drive a two-phase motor with an external AC power source or with the power of an internal storage battery in a small, low-cost circuit is realized.

  Note that the control means 15 and the control means 44 in the second embodiment may be realized by software logic such as a microcomputer, or may be realized by a hardware logic circuit. Not too long.

(Embodiment 3)
FIG. 8: is a block diagram which shows the detailed structure of the vacuum cleaner which concerns on the 3rd Embodiment of this invention. In this electric vacuum cleaner, a fan motor 50, a motor driving device 51 for driving the fan motor 50, and a storage battery 52 provided therein are provided.

  The motor drive device 51 drives the fan motor 50 by the AC power supplied from the AC power cable 53, so that the fan rotates, thereby realizing the suction function of the vacuum cleaner. Further, when AC power is not supplied from the AC power supply cable 53, the fan motor 50 is driven using the power of the storage battery 52 provided therein to rotate the fan. Furthermore, the charging of the storage battery 52 is realized by converting the AC power supplied from the AC power cable 53 into DC power by the internal motor driving device 51.

  As described above, in the vacuum cleaner according to the third embodiment, the AC power supplied from the AC power supply cable 53 is converted into power having an arbitrary frequency by the motor driving device 51 to drive the connected fan motor 50. Realize the cleaning function. Furthermore, since the fan motor 50 is driven also by the electric power of the storage battery 52, a cleaning function is realized even when power is not supplied from the outside. Furthermore, since the storage battery 52 is charged by the inverter circuit in the motor drive device 51, a small and low-cost vacuum cleaner that can obtain a vacuum cleaner function by both the external AC power supply and the power of the internal storage battery is realized. Is.

As described above, the present invention relates to a motor drive device that drives a motor, and particularly useful for a motor drive device that can be operated by an external power source or an internal storage battery, and that further achieves a small size, light weight, and low cost. It is. Moreover, it is useful regarding the vacuum cleaner using it.

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Switching circuit 2a Switching element 3 Switching circuit 3a Switching element 4 Switching circuit 4a Switching element 5 Switching circuit 5a Switching element 6 Switching circuit 6a Switching element 7 Switching circuit 7a Switching element 8 Motor 9 Rectification circuit 10 Boosting coil 11 Diode 12 Step-up switching element 13 Smoothing capacitor 14 Storage battery 15 Control means 20 Motor drive device 22 Inverter circuit 31 AC power supply 32 Switching circuit 32a Switching element 33 Switching circuit 33a Switching element 34 Switching circuit 34a Switching element 35 Switching circuit 35a Switching element 40 Motor 41 Rectification Circuit 42 Smoothing capacitor 43 Storage battery 4 Control means 47 a motor driving device 48 inverter circuit 50 fan motor 51 motor driving device 52 storage battery 54 diode

Claims (11)

An inverter circuit that drives a motor externally connected by converting the power of the external power source into power of an arbitrary frequency using a DC external power source as input, a storage battery connected to the input / output side of the inverter circuit, and the motor At the time of driving, the motor is driven by the inverter circuit using the power of the storage battery or the power of the external power source, and at the time of charging the storage battery, DC power is output to one phase of the output of the inverter circuit, A motor drive device comprising: control means having a control function of charging the storage battery using DC power. A converter for converting the power of the external power source into a direct current using an AC external power source as an input; an inverter circuit for driving an externally connected motor by converting the power output from the converter into an electric power of an arbitrary frequency; A storage battery connected to the input / output side of the inverter circuit, and when driving the motor, the inverter circuit uses the power of the storage battery or the power of the external power source to drive the motor, and when charging the storage battery, the inverter circuit A motor drive device comprising: control means having a control function for outputting direct current power to one phase of the outputs of the output and charging the storage battery using the direct current power. The inverter circuit includes a switching element for three phases, with two switching elements connected in series as one phase, and the control means switches the switching elements for three phases when the motor is driven. Three-phase arbitrary frequency power is output to drive a three-phase motor, and at the time of charging the storage battery, only one of the three-phase switching elements of the inverter circuit is switched. The motor driving apparatus according to claim 1, wherein control for outputting direct-current power is performed. The inverter circuit includes a switching element for two phases, with two switching elements for one phase, and the control means switches any two-phase switching element by switching the switching elements for two phases when the motor is driven. Outputs power at a frequency to drive a two-phase motor, and when charging the storage battery, outputs DC power by switching only one of the two-phase switching elements of the inverter circuit. The motor driving apparatus according to claim 1, wherein control is performed. A first switch is provided between the storage battery and the input side of the inverter circuit, and a second switch is provided between the storage battery and the output side of the inverter circuit. The first switch is turned on when the motor is driven with electric power, and the second switch is turned on when the storage battery is charged with electric power from the external power source. The motor drive device according to item. The input side of the inverter circuit is provided with voltage detection means for detecting the voltage of the input unit. When the detected voltage is a predetermined value or less, the motor is driven by the power of the storage battery and the detected voltage is The motor according to any one of claims 1 to 5, further comprising control means for controlling the driving of the motor with the electric power of the external power source or charging the storage battery when the predetermined value or more is reached. Drive device. On the input side from the external power source of the converter is provided with voltage detection means for detecting the voltage of the input, and when the detected voltage is below a predetermined value, the motor is driven by the power of the storage battery and detected 6. The control device according to any one of claims 2 to 5, further comprising control means for controlling the motor to be driven by the electric power from the external power source or to charge the storage battery when the voltage is equal to or higher than the predetermined value. The motor drive device described. The motor drive according to any one of claims 1 to 7, further comprising a booster circuit connected to an input side of the inverter circuit, wherein an output of the storage battery is connected to an input side of the booster circuit. apparatus. The input side of the booster circuit is provided with voltage detection means for detecting the voltage of the input unit. When the detected voltage is a predetermined value or less, the motor is driven by the power of the storage battery and the detected voltage is 9. The motor driving apparatus according to claim 8, further comprising control means for controlling the motor to be driven by the electric power of the external power source or to charge the storage battery when the predetermined value is exceeded. A third switch is provided on the input side from the external power source, and the control means turns on the third switch when driving the motor with the power from the external power source or charging the storage battery. The motor drive device according to claim 2, wherein the motor drive device is a motor drive device. An electric vacuum cleaner characterized in that the fan motor drive device is constituted by the motor drive device according to any one of claims 1 to 10.