JP2021184692A - Power conversion device, control method and program - Google Patents

Abstract

To provide a device effective to suppression of reversal of an electric motor at the time of starting.SOLUTION: A power conversion device 1 includes a first search control unit 112 for causing a power conversion circuit 10 to supply a search output to a motor 20, a magnetic pole position estimation unit 113 for estimating the position of a magnetic pole of the motor 20 based on a response to the search output, a condition setting unit 114 for setting a pulse supply condition according to an estimation result, a second search control unit 115 for causing the power conversion circuit 10 to supply a positive pulse output and a negative pulse output to the motor 20, a difference evaluation unit 116 for evaluating the difference between the magnitude of a response to the positive pulse output and the magnitude of a response to the negative pulse output, a condition changing unit 117 for repeating changing the pulse supply condition and causing the difference evaluation unit 116 to evaluate the difference until an evaluation result exceeds a predetermined level, and a polarity estimation unit 118 for estimating the polarity of the magnetic pole of the motor 20 based on the evaluation result.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to power converters, control methods and programs.

In Patent Document 1, a predetermined phase correction value is added to the phase of the output voltage when the synchronous electric motor is started, the phase correction value is changed at least once, and the frequency of the output voltage is changed based on the detected value of the output current. A device that calculates a correction value and corrects the frequency of an output voltage is disclosed.

Japanese Unexamined Patent Publication No. 2007-259610

The present disclosure provides a device effective for suppressing reverse rotation of a motor at the time of starting.

The power conversion device according to one aspect of the present disclosure includes a first search control unit that supplies a search output from the power conversion circuit to the motor, and a magnetic pole position estimation unit that estimates the position of the magnetic pole of the motor based on the response to the search output. , A condition setting unit that sets the pulse supply condition according to the estimation result of the position of the magnetic pole, a second search control unit that supplies the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the pulse supply condition, and the positive pulse. A difference evaluation unit that evaluates the difference between the magnitude of the response to the output and the magnitude of the response to the negative pulse output, changing the pulse supply conditions, and outputting a positive pulse to the second search control unit according to the changed pulse supply conditions. And the condition change part that repeats supplying a negative pulse output and having the difference evaluation unit evaluate the difference until the difference evaluation result exceeds a predetermined level, and the polarity of the magnetic pole based on the difference evaluation result. It is provided with a polarity estimation unit for estimation.

The power conversion device according to another aspect of the present disclosure is based on a first search control unit that supplies a search output from a power conversion circuit to a motor having a sensor that detects a change in the position of a magnetic pole, and a response to the search output. A power pole position estimation unit that estimates the position of the magnetic poles of the motor, a condition setting unit that sets pulse supply conditions according to the estimation result of the magnetic pole position, and a power conversion circuit that converts positive pulse output and negative pulse output according to the pulse supply conditions. The second search control unit that supplies power from the motor to the motor, the difference evaluation unit that evaluates the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output, and the polarity of the magnetic poles based on the evaluation result of the difference. The polarity estimation unit to be estimated, the magnetic pole position update unit that updates the estimation result of the magnetic pole position by the magnetic pole position estimation unit based on the detection result by the sensor, and the estimation result of the magnetic pole position updated by the magnetic pole position update unit. Based on the estimation result of the polarity of the magnetic pole by the polarity estimation unit, the drive control unit that supplies the drive power from the power conversion circuit to the motor, and the change in the position of the magnetic pole detected by the sensor according to the supply of the drive power. It includes an error detection unit that detects an error in estimating the polarity of the magnetic pole based on the direction.

The control method according to still another aspect of the present disclosure is to supply the motor with a search output from the power conversion circuit, to estimate the position of the magnetic pole of the motor based on the response to the search output, and to estimate the position of the magnetic pole. Setting the pulse supply condition according to the result, supplying the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the pulse supply condition, the magnitude of the response to the positive pulse output, and the response to the negative pulse output. Evaluate the difference from the magnitude of, change the pulse supply condition, supply the positive pulse output and negative pulse output from the power conversion circuit to the motor according to the changed pulse supply condition, and evaluate the difference. This includes repeating until the difference evaluation result exceeds a predetermined level, and estimating the polarity of the magnetic pole based on the difference evaluation result.

A control method according to still another aspect of the present disclosure is to supply a search output from a power conversion circuit to an electric motor having a sensor for detecting a change in the position of a magnetic pole, and a magnetic pole of the motor based on a response to the search output. Estimating the position of, setting the pulse supply condition according to the estimation result of the position of the magnetic pole, and supplying the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the pulse supply condition. The sensor evaluates the difference between the magnitude of the response to the pulse output and the magnitude of the response to the negative pulse output, estimates the polarity of the magnetic pole based on the evaluation result of the difference, and estimates the position of the magnetic pole. Update based on the detection result, supply drive power to the motor from the power conversion circuit based on the estimation result of the updated magnetic pole position and the estimation result of the polarity of the magnetic pole, and supply the drive power. Includes detecting an error in estimating the polarity of the magnetic poles based on the direction of change in the position of the magnetic poles detected by the sensor.

The program according to still another aspect of the present disclosure is to supply a search output to a motor from a power conversion circuit, estimate the position of a magnetic pole of the motor based on the response to the search output, and estimate the position of the magnetic pole. The pulse supply conditions are set according to the conditions, the positive pulse output and the negative pulse output are supplied from the power conversion circuit to the motor according to the pulse supply conditions, the magnitude of the response to the positive pulse output, and the response to the negative pulse output. To evaluate the difference from the magnitude, to change the pulse supply condition, to supply the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the changed pulse supply condition, and to evaluate the difference. This is a program for causing the device to repeat the process until the difference evaluation result exceeds a predetermined level, and to estimate the polarity of the magnetic pole based on the difference evaluation result.

The program according to still another aspect of the present disclosure is to supply a search output from a power conversion circuit to a motor having a sensor for detecting a change in the position of the magnetic pole, and to supply a search output to the motor's magnetic pole based on the response to the search output. Estimating the position, setting the pulse supply condition according to the estimation result of the position of the magnetic pole, supplying the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the pulse supply condition, and positive pulse. Evaluating the difference between the magnitude of the response to the output and the magnitude of the response to the negative pulse output, estimating the polarity of the magnetic pole based on the evaluation result of the difference, and detecting the estimation result of the position of the magnetic pole by the sensor. Based on the update based on the result, the estimation result of the position of the updated magnetic pole, and the estimation result of the polarity of the magnetic pole, the power conversion circuit supplies the drive power to the motor, and the drive power is supplied. Accordingly, it is a program for causing the apparatus to detect an error in estimating the polarity of the magnetic pole based on the change direction of the position of the magnetic pole detected by the sensor.

According to the present disclosure, it is possible to provide a device effective for suppressing reverse rotation of a motor at the time of starting.

It is a schematic diagram which illustrates the structure of the power conversion apparatus. It is a schematic diagram which illustrates the relationship between a magnetic pole position, a positive pulse output and a negative pulse output. It is a graph which illustrates the magnitude of the response to a positive pulse output, and the magnitude of the response to a negative pulse output. It is a block diagram which illustrates the hardware composition of a control circuit. It is a flowchart which illustrates the control procedure. It is a flowchart illustrating the 1st search control procedure. It is a flowchart illustrating the 2nd search control procedure. It is a schematic diagram which shows the modification of the power conversion apparatus. It is a flowchart which shows the modification of the control procedure.

Hereinafter, embodiments will be described in detail with reference to the drawings. In the description, the same elements or elements having the same function are designated by the same reference numerals, and duplicate description will be omitted.

〔Device〕
The power conversion device 1 according to the present embodiment is a device that supplies drive power to the motor 20 (motor). The motor 20 is a synchronous motor in which the rotor has a magnetic pole. Specific examples of the synchronous motor in which the rotor has a magnetic pole include a permanent magnet type synchronous motor and the like. Specific examples of the permanent magnet type synchronous motor include an SPM (Surface Permanent Magnet) motor, an IPM (Interior Permanent Magnet) motor, and the like. The motor 20 may be a synchronous motor in which the rotor has a salient polarity. Specific examples of a synchronous motor in which the rotor has a salient polarity include an IPM motor and the like.

The motor 20 illustrated in FIG. 2 is an IPM motor and has a stator 30 and a rotor 40. The stator 30 has an annular yoke 31, a plurality of teeth 32, and a plurality of coils 33. The plurality of teeth 32 are arranged at equal intervals along the circumferential direction of the yoke 31. Each of the plurality of teeth 32 projects from the inner circumference of the yoke 31 toward the center of the yoke 31. The plurality of teeth 32 are arranged at equal intervals along the rotation direction of the rotor 40 (rotation direction of the magnetic poles) at a predetermined angular pitch (60 ° in the figure). The plurality of coils 33 are attached to the plurality of teeth 32, respectively. The stator 30 generates a magnetic field that rotates around the center of the yoke 31 in response to the supply of electric power to the plurality of coils 33.

The rotor 40 has a shaft 41, a rotor core 42, and a plurality of permanent magnets 43. The shaft 41 rotates around the center of the yoke 31. The rotor core 42 is made of a soft magnetic material and is fixed to the outer periphery of the yoke 31. The plurality of permanent magnets 43 are embedded in the rotor core 42, and form a plurality of magnetic poles in the rotor 40. In the illustrated example, the four permanent magnets 43a, 43b, 43c, 43d form the four magnetic poles 40a, 40b, 40c, 40d, respectively.

As shown in FIG. 1, the power conversion device 1 converts the power (primary side power) of the power supply 90 into drive power (secondary side power) and supplies it to the motor 20. The primary power may be AC power or DC power. The secondary power is AC power. As an example, both the primary side power and the secondary side power are three-phase AC power. For example, the power conversion device 1 has a power conversion circuit 10 and a control circuit 100.

The power conversion circuit 10 converts the primary side electric power into the secondary side electric power and supplies it to the motor 20. The power conversion circuit 10 is, for example, a voltage type inverter, and applies a drive voltage according to a voltage command to the motor 20. For example, the power conversion circuit 10 includes a converter circuit 11, a smoothing capacitor 12, an inverter circuit 13, and a current sensor 14. The converter circuit 11 is, for example, a diode bridge circuit or a PWM converter circuit, and converts the power supply power into DC power. The smoothing capacitor 12 smoothes the DC power.

The inverter circuit 13 performs power conversion between the DC power and the drive power. For example, the inverter circuit 13 has a plurality of switching elements 15, and performs the power conversion by switching on / off of the plurality of switching elements 15. The switching element 15 is, for example, a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like, and switches on / off according to a gate drive signal. The current sensor 14 detects the current flowing between the inverter circuit 13 and the motor 20. For example, the current sensor 14 may be configured to detect the current of all three-phase alternating current (U-phase, V-phase, and W-phase), or detect the current of any two-phase of three-phase alternating current. It may be configured as follows. Since the total of the U-phase, V-phase, and W-phase currents is zero unless a zero-phase current is generated, information on the currents of all phases can be obtained even when two-phase currents are detected.

The configuration of the power conversion circuit 10 shown above is only an example, and can be changed in any way as long as the drive power can be supplied to the motor 20. For example, the power conversion circuit 10 may be a current type inverter. The current type inverter outputs a drive current according to the current command to the motor 20. The power conversion circuit 10 may be a matrix converter circuit that performs bidirectional power conversion between power supply power and drive power without going through direct current conversion. When the power source power is DC power, the power conversion circuit 10 does not have to have the converter circuit 11.

The control circuit 100 controls the power conversion circuit 10 so as to supply drive power to the motor 20. For example, when the power conversion circuit 10 is a voltage type inverter, the control circuit 100 controls the power conversion circuit 10 so as to apply a drive voltage according to a voltage command to the motor 20. When the power conversion circuit 10 is a current type inverter, the control circuit 100 controls the power conversion circuit 10 so as to supply the drive current according to the current command to the motor 20.

Here, in order to drive the motor 20, it is necessary to adjust the phase of the current flowing through the stator 30 by supplying the driving power based on the position of the magnetic pole of the rotor 40 (for example, the position of the magnetic pole 40a). The control circuit 100 has a function of detecting the position of the magnetic pole using a sensor or without a sensor. While driving the motor 20, the control circuit 100 estimates, for example, based on sensor information or based on voltage commands, the drive current supplied to motor 20 accordingly, and frequency commands. Detect the position of the magnetic pole. However, immediately after the power is turned on to the control circuit 100, the position of the magnetic pole cannot be detected unless a sensor such as an absolute value encoder is used. If the driving of the motor 20 is started in a state where the position and polarity of the magnetic poles at the time of rising of the control circuit 100 are unknown, the subsequent detection of the positions of the magnetic poles is not performed correctly, and there is a possibility that the rotor 40 is reversed, for example. ..

On the other hand, the control circuit 100 causes the motor 20 to supply the search output from the power conversion circuit 10, estimates the position of at least one magnetic pole of the motor 20 based on the response to the search output, and positions the magnetic poles. The pulse supply conditions are set according to the estimation result of the above, the positive pulse output and the negative pulse output are supplied from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, the magnitude of the response to the positive pulse output, and the negative. Evaluating the difference from the magnitude of the response to the pulse output (hereinafter referred to as "response difference"), changing the pulse supply conditions, and powering the positive pulse output and negative pulse output according to the changed pulse supply conditions. Supplying the motor 20 from the conversion circuit 10 and evaluating the response difference are repeated until the evaluation result of the response difference exceeds a predetermined level, and at least one of the motor 20 is evaluated based on the evaluation result of the response difference. It is configured to estimate the polarity of one pole and to perform.

According to such a configuration, when the evaluation result of the difference between the positive pulse output and the negative pulse output does not exceed a predetermined level, the supply of the positive pulse output and the negative pulse output and the evaluation of the above difference are repeated. Therefore, false detection of polarity based on the difference is suppressed. Therefore, the reversal of the motor 20 due to the false detection of the polarity of the magnetic pole is suppressed, which is effective in suppressing the reversal of the motor 20.

For example, the control circuit 100 supplies the motor 20 with a high-frequency search output that the rotor 40 cannot follow from the power conversion circuit 10. When the power conversion circuit 10 is a voltage type inverter, the control circuit 100 applies a high-frequency search voltage (search output) from the power conversion circuit 10 to the motor 20 and supplies the high frequency search voltage to the motor 20 in response to the application of the search voltage. Estimate the position of at least one magnetic pole based on the search current (response). Further, the control circuit 100 applies a positive pulse voltage (positive pulse output) and a negative pulse voltage (negative pulse output) from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, and supplies the positive pulse voltage to the motor 20 according to the positive pulse voltage. The difference (response difference) between the positive current generated and the negative current supplied to the motor 20 according to the negative pulse voltage is evaluated.

When the power conversion circuit 10 is a current type inverter, the control circuit 100 supplies a high-frequency search current (search output) from the power conversion circuit 10 to the motor 20 and applies the high-frequency search current to the motor 20 in response to the supply of the search current. Estimate the position of at least one magnetic pole based on the search voltage (response). Further, the control circuit 100 supplies a positive pulse current (positive pulse output) and a negative pulse current (negative pulse output) from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, and applies the positive pulse current to the motor 20 according to the positive pulse current. The difference (response difference) between the positive voltage generated and the negative voltage applied to the motor 20 according to the negative pulse current is evaluated. Hereinafter, the configuration of the control circuit 100 when the power conversion circuit 10 is a voltage type inverter will be more specifically exemplified.

As shown in FIG. 1, the control circuit 100 has a PWM control unit 111, a first search control unit 112, a magnetic pole position estimation unit 113, and conditions as a functional configuration (hereinafter referred to as “functional block”). It has a setting unit 114, a second search control unit 115, a difference evaluation unit 116, a condition change unit 117, a polarity estimation unit 118, and a drive control unit 121.

The PWM control unit 111 controls the power conversion circuit 10 so as to apply a drive voltage according to the voltage command to the motor 20. For example, the PWM control unit 111 switches on / off of a plurality of switching elements 15 of the inverter circuit 13 so as to apply a drive voltage corresponding to a voltage command vector in a fixed coordinate system fixed to the stator 30 to the motor 20.

The first search control unit 112 applies a high-frequency search voltage to the motor 20 from the power conversion circuit 10. For example, the first search control unit 112 generates a search voltage command for applying the search voltage to the power conversion circuit 10 and outputs the search voltage command to the PWM control unit 111. The search voltage command includes, for example, a time change in the phase of the voltage command vector in a fixed coordinate system.

As shown in FIG. 2, the fixed coordinate system has an α-axis with the rotation center of the rotor 40 as the origin, and a β-axis having an angle of 90 degrees with the α-axis at an electric angle. The search voltage command includes a time change with the phase angle of the voltage command vector with respect to the α axis.

Returning to FIG. 1, the magnetic pole position estimation unit 113 estimates the position of at least one magnetic pole of the motor 20 based on the search current (response to the search output) supplied to the motor 20 in response to the application of the search voltage. For example, the magnetic pole position estimation unit 113 acquires the detection result of the search current from the current sensor 14. The magnetic pole position estimation unit 113 may estimate the position of any one of the magnetic poles 40a, 40b, 40c, and 40d, or may estimate the position of each of the magnetic poles 40a, 40b, 40c, and 40d. For example, the magnetic pole position estimation unit 113 has a magnetic pole position θ1 which is a position of the center of the magnetic pole 40a and a magnetic pole position θ2 which is a position of the center of the magnetic pole 40b at an angle around the rotation center of the rotor 40 with respect to the α axis. , The magnetic pole position θ3, which is the center position of the magnetic pole 40c, and the magnetic pole position θ4, which is the center position of the magnetic pole 40d, are estimated (see FIG. 2).

The condition setting unit 114 sets the pulse supply condition according to the estimation result of the position of the magnetic pole. For example, the condition setting unit 114 sets the pulse supply condition according to the estimation result of the magnetic pole position θ1. The pulse supply conditions are the conditions for applying the positive pulse voltage and the negative pulse voltage. The positive pulse voltage is a voltage that generates a single magnetic flux vector in a predetermined direction in a fixed coordinate system in a short period of time in which the movement of the rotor 40 is limited to a slight movement. The negative pulse voltage is a voltage that generates a magnetic flux vector in the opposite direction to the magnetic flux vector due to the positive pulse voltage in a short period of time in which the movement of the rotor 40 is kept in a slight movement.

The conditions for applying the positive pulse voltage and the negative pulse voltage are the pulse phase condition that determines the phase of the positive pulse voltage and the negative pulse voltage, the pulse width condition that determines the pulse width (time width) of the positive pulse voltage and the negative pulse voltage, and the positive pulse width condition. Includes pulse magnitude conditions that determine the magnitude of the pulse voltage and negative pulse voltage. For example, the condition setting unit 114 determines the pulse phase condition so that the phases of the positive pulse voltage and the negative pulse voltage correspond to the magnetic pole position θ1 based on the estimation result of the magnetic pole position θ1. As an example, the condition setting unit 114 allows the magnetic flux vector MV1 generated by the application of the positive pulse voltage PV1 and the magnetic flux vector MV2 generated by the application of the negative pulse voltage PV2 to pass through the position of at least one magnetic pole (for example, the position of the magnetic pole 40a). Determine the pulse phase conditions (see Figure 2). In the illustrated example, it can be recognized that passing through the permanent magnet 43 means passing through the magnetic pole, but depending on the arrangement of the permanent magnet 43, it may be unclear how far the magnetic pole range is. obtain. In such a case, passing through the magnetic pole means, for example, passing within ± 30 ° in electrical angle with respect to the position of the center of the magnetic pole.

The condition setting unit 114 determines the pulse width condition so that the pulse width of the positive pulse voltage and the pulse width of the negative pulse voltage have the same predetermined value, and the magnitude of the positive pulse voltage and the magnitude of the negative pulse voltage are the same predetermined value. The pulse magnitude condition is determined so as to be. The predetermined value is preset so that the rotor 40 is not moved or the movement of the rotor 40 is at least finely moved. For example, the predetermined value is preset so that the magnetic flux vectors MV1 and MV2 do not deviate from the magnetic poles even if the rotor 40 is slightly moved by the application of the positive pulse voltage and the negative pulse voltage.

FIG. 3 is a graph showing the relationship between the elapsed time and the magnitude of the voltage vector. In this graph, the positive pulse voltage PV1 is a single-shot square wave protruding in the positive direction, and the negative pulse voltage PV2 is a single-shot square wave protruding in the negative direction. In FIG. 3, the application period T1 corresponds to the width of the positive pulse voltage PV1, and the application period T2 corresponds to the width of the negative pulse voltage PV2. Further, the applied voltage V1 corresponds to the magnitude of the positive pulse voltage PV1, and the applied voltage V2 corresponds to the magnitude of the negative pulse voltage PV2.

As shown in FIG. 3, the condition setting unit 114 may set the pulse supply condition so that the positive pulse voltage PV1 and the negative pulse voltage PV2 are applied in this order. On the contrary, the condition setting unit 114 may set the pulse supply condition so that the negative pulse voltage PV2 and the positive pulse voltage PV1 are applied in this order. Further, the condition setting unit 114 may set the pulse supply condition so as to allow a predetermined period between the positive pulse voltage PV1 and the negative pulse voltage PV2. For example, the predetermined period is set so that the current generated by the application of the earlier pulse voltage becomes zero before the application of the later pulse voltage.

Returning to FIG. 1, the second search control unit 115 applies a positive pulse voltage and a negative pulse voltage from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions. For example, the second search control unit 115 generates a voltage command for applying the positive pulse voltage PV1 and the negative pulse voltage PV2 from the power conversion circuit 10 to the motor 20, and outputs the voltage command to the PWM control unit 111.

The difference evaluation unit 116 is a difference between the magnitude of the positive current supplied to the motor 20 in response to the application of the positive pulse voltage and the magnitude of the negative current supplied to the motor 20 in response to the application of the negative pulse voltage (the response described above). Difference) is evaluated. For example, the difference evaluation unit 116 acquires the detection results of the positive current and the negative current from the current sensor 14.

As long as the magnitude of the response difference can be evaluated quantitatively, there is no particular limitation on the method for evaluating the response difference. For example, as illustrated in FIG. 3, the difference evaluation unit 116 supplies the magnitude of the positive current RA1 supplied to the motor 20 in response to the application of the positive pulse voltage PV1 and the magnitude of the positive current RA1 in response to the application of the negative pulse voltage PV2 to the motor 20. The difference from the magnitude of the negative current RA2 to be generated is evaluated as the response difference.

The difference evaluation unit 116 may evaluate the response difference based on the difference between the integrated value of the magnitude of the positive current RA1 and the integrated value of the magnitude of the negative current RA2. The difference evaluation unit 116 may evaluate the response difference based on the difference between the average value of the magnitudes of the positive current RA1 and the average value of the magnitudes of the negative current RA2. The difference evaluation unit 116 may evaluate the response difference based on the difference between the maximum value of the magnitude of the positive current RA1 and the maximum value of the magnitude of the negative current RA2.

The magnitude relationship between the magnitude of the positive current RA1 and the magnitude of the negative current RA2 changes depending on the polarity of the magnetic pole (for example, the polarity of the magnetic pole 40a). For example, when the direction of the magnetic flux generated by the application of the positive pulse voltage PV1 (the direction of the magnetic flux vector MV1) coincides with the direction of the magnetic flux generated by the magnetic pole 40a at the magnetic pole position θ1 (hereinafter referred to as “magnet magnetic flux direction”), the magnetic flux. The positive current RA1 becomes larger as compared with the case where the direction of the vector MV1 is opposite to the direction of the magnetic flux of the magnet. Similarly, when the direction of the magnetic flux generated by the application of the negative pulse voltage PV2 (the direction of the magnetic flux vector MV2) coincides with the magnetic flux direction of the magnet, the direction of the magnetic flux vector MV2 is opposite to the direction of the magnetic flux of the magnet. Therefore, the negative current RA2 becomes large. Therefore, when the width and magnitude of the positive pulse voltage PV1 and the width and magnitude of the negative pulse voltage PV2 are equal, it is possible to estimate the magnetic flux direction of the magnet based on the magnitude relationship between the positive current RA1 and the negative current RA2. For example, when the above-mentioned response difference is a positive value, the polarity of the magnetic pole 40a is estimated to be the polarity (for example, N pole) in which the magnetic flux direction of the magnet matches the magnetic flux vector MV1. When the response difference is a negative value, the polarity of the magnetic pole 40a is estimated to be the polarity (for example, the S pole) in which the magnetic flux direction of the magnet matches the magnetic flux vector MV2. However, in the actual motor 20, when the positive pulse voltage PV1 and the negative pulse voltage PV2 are applied, the magnitude of the response difference changes depending on which part of the rotor 40 the teeth 32 faces. For example, the magnitude of the response difference varies depending on whether the teeth 32 face the permanent magnets 43 or the teeth 32 face each other between the permanent magnets 43. Due to such an influence in the actual environment, when the magnitude of the response difference is small, an error may occur in the estimation result of the polarity of the magnetic pole.

On the other hand, the condition changing unit 117 changes the pulse supply condition, applies the positive pulse voltage and the negative pulse voltage to the second search control unit 115 according to the changed pulse supply condition, and the difference evaluation unit 116. To evaluate the response difference, and repeat until the evaluation result of the response difference exceeds a predetermined level.

For example, the condition changing unit 117 may change the pulse supply condition so as to change the direction of the magnetic flux vector generated by the supply of the positive pulse voltage and the negative pulse voltage. As an example, the condition changing unit 117 changes the pulse phase condition so as to change the direction of the magnetic flux vectors MV1 and MV2 within a range in which the magnetic flux vectors MV1 and MV2 in FIG. 2 do not deviate from the same magnetic pole. For example, the condition changing unit 117 is the magnetic flux vector MV1 and MV1 within the range of the magnetic poles through which the magnetic flux vectors MV1 and MV2 are passed under the pulse phase condition determined by the condition setting unit 114 (within ± 30 ° with respect to the position of the center of the magnetic poles). The pulse phase condition is changed so as to change the direction of MV2.

The condition changing unit 117 may specify the change angle of the direction of the magnetic flux vector based on the angle pitch of the coil 33, and change the pulse supply condition so as to change the direction of the magnetic flux vector according to the change angle. For example, the condition changing unit 117 substantially changes the direction of the magnetic flux vector at an angle obtained by multiplying half the pitch of the angle pitch (0.5 times the angle pitch) by an odd number (for example, 1 times, 3 times, or 5 times, etc.). The pulse supply conditions may be changed to change.

The condition changing unit 117 indicates that the magnetic flux vectors MV1 and MV2 are any of the magnetic poles 40b, 40c, and 40d when the response difference does not exceed a predetermined level while the magnetic flux vectors MV1 and MV2 pass through the magnetic poles 40a (first magnetic pole). The pulse phase condition may be changed so as to pass through (second magnetic flux). For example, in the condition changing unit 117, when the response difference does not exceed a predetermined level in a state where the magnetic flux vectors MV1 and MV2 pass through the magnetic pole 40a (first magnetic pole), the magnetic flux vectors MV1 and MV2 perform the magnetic flux 40b (second magnetic pole). The pulse phase condition may be changed so as to pass. Further, in the condition changing unit 117, when the response difference does not exceed a predetermined level in a state where the magnetic flux vectors MV1 and MV2 pass through the magnetic pole 40b (first magnetic pole), the magnetic flux vectors MV1 and MV2 perform the magnetic flux 40c (second magnetic pole). The pulse phase condition may be changed so as to pass. Further, the condition changing unit 117 causes the magnetic flux vectors MV1 and MV2 to set the magnetic poles 40d (second magnetic pole) when the response difference does not exceed a predetermined level while the magnetic flux vectors MV1 and MV2 pass through the magnetic poles 40c (first magnetic pole). The pulse phase condition may be changed so as to pass.

The condition changing unit 117 may change the pulse supply condition so as to change the magnitudes of the positive pulse voltage and the negative pulse voltage. For example, the condition changing unit 117 may change the pulse magnitude condition so as to increase the magnitude of the applied voltage V1 of the positive pulse voltage PV1 and the applied voltage V2 of the negative pulse voltage PV2. The condition changing unit 117 may change the pulse supply condition so as to change the width of the positive pulse voltage and the negative pulse voltage. For example, the condition changing unit 117 may change the pulse width condition so as to lengthen the application period T1 of the positive pulse voltage PV1 and the application period T2 of the negative pulse voltage PV2. The condition changing unit 117 changes the direction of the magnetic flux vector generated by the supply of the positive pulse voltage and the negative pulse voltage, changes the magnitude of the positive pulse voltage and the negative pulse voltage, and the width of the positive pulse voltage and the negative pulse voltage. And 2 or more of the 3 types may be combined and executed.

The polarity estimation unit 118 estimates the polarity of the magnetic pole 40a based on the evaluation result of the response difference exceeding the predetermined level. If a response difference exceeding a predetermined level is obtained according to the pulse supply conditions through which the magnetic flux vectors MV1 and MV2 pass through the other magnetic poles 40a, the other magnetic poles of the other magnetic poles are based on the evaluation result of the response difference. The polarity is estimated. If the polarities of the other magnetic poles are determined, the polarities of the magnetic poles 40a are naturally determined. Therefore, estimating the polarities of the other magnetic poles corresponds to estimating the magnetic poles of the magnetic poles 40a.

The drive control unit 121 supplies drive power from the power conversion circuit 10 to the motor 20 based on the estimation result of the position of the magnetic pole by the magnetic pole position estimation unit 113 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118. Let's get started. For example, the drive control unit 121 generates a voltage command for supplying drive power to the motor 20 from the power conversion circuit 10 and outputs the voltage command to the PWM control unit 111. For example, the drive control unit 121 specifies the position of the magnetic pole based on the estimation result of the position of the magnetic pole by the magnetic pole position estimation unit 113 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118. In this case, an estimated value of the position of the magnetic pole that creates the magnetic flux whose direction coincides with the magnetic flux vector MV1 is specified at the position of the magnetic pole. Hereinafter, the magnetic pole whose position is specified is referred to as a "positive magnetic pole". The drive control unit 121 generates a voltage command in a rotating coordinate system in which the rotation speed is determined so as to rotate in synchronization with the positive magnetic pole. For example, the drive control unit 121 generates a voltage command in the rotating coordinate system so that the drive current supplied to the motor 20 follows the current command. After that, the drive control unit 121 calculates the voltage command vector in the above-mentioned fixed coordinate system based on the voltage command in the rotating coordinate system and the position of the positive magnetic pole, and transfers the calculated voltage command vector to the PWM control unit 111. Output.

After that, the drive control unit 121 calculates the magnetic pole position based on the output of the rotation detection sensor (for example, an encoder), or estimates the magnetic pole position without a sensor (for example, a voltage command and a drive current and a frequency supplied to the motor 20 in response to the voltage command). The magnetic pole position estimation based on the command) is performed, the voltage command vector in the fixed coordinate system is updated based on the position of the positive magnetic pole thus obtained, and the voltage command vector is repeatedly output to the PWM control unit 111. As a result, the supply of drive power according to the position of the positive magnetic pole is continued. The drive control unit 121 acquires the detection result of the drive current from the current sensor 14.

FIG. 4 is a schematic diagram illustrating the hardware configuration of the control circuit 100. As shown in FIG. 4, the control circuit 100 includes one or more processors 191 and a memory 192, a storage 193, an input / output port 194, and a switching control circuit 195. The storage 193 has a computer-readable storage medium, such as a non-volatile semiconductor memory. The storage 193 responds to the power conversion circuit 10 supplying the motor 20 with a search output, estimating the position of at least one magnetic pole of the motor 20 based on the response to the search output, and estimating the position of the magnetic poles. The pulse supply conditions are set, the positive pulse output and the negative pulse output are supplied from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, the magnitude of the response to the positive pulse output, and the response to the negative pulse output. Evaluating the difference from the magnitude, changing the pulse supply conditions, supplying positive pulse output and negative pulse output from the power conversion circuit 10 to the motor 20 according to the changed pulse supply conditions, and evaluating the difference. This is repeated until the difference evaluation result exceeds a predetermined level, and the polarity of at least one magnetic pole of the motor 20 is estimated based on the difference evaluation result, in order to cause the control circuit 100 to execute. I remember the program of. For example, the storage 193 stores a program for configuring each of the above-mentioned functional blocks in the control circuit 100.

The memory 192 temporarily stores the program loaded from the storage medium of the storage 193 and the calculation result by the processor 191. The processor 191 constitutes each functional block of the control circuit 100 by executing the above program in cooperation with the memory 192. The input / output port 194 inputs / outputs an electric signal to / from the current sensor 14 according to a command from the processor 191. The switching control circuit 195 outputs the drive power to the motor 20 by switching on and off of the plurality of switching elements 15 in the inverter circuit 13 according to a command from the processor 191.

The control circuit 100 is not necessarily limited to the one that configures each function by a program. For example, the control circuit 100 may be configured with at least a part of a function by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates the logic circuit.

[Control procedure]
Subsequently, as an example of the control method, a start control procedure of the motor 20 executed by the control circuit 100 will be illustrated. This procedure depends on feeding the motor 20 a search output from the power conversion circuit 10, estimating the position of at least one magnetic pole of the motor 20 based on the response to the search output, and estimating the position of the magnetic poles. The pulse supply conditions are set, the positive pulse output and the negative pulse output are supplied from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, the magnitude of the response to the positive pulse output, and the response to the negative pulse output. Evaluating the difference from the magnitude, changing the pulse supply conditions, supplying positive pulse output and negative pulse output from the power conversion circuit 10 to the motor 20 according to the changed pulse supply conditions, and evaluating the difference. This includes repeating until the difference evaluation result exceeds a predetermined level, and estimating the polarity of at least one magnetic pole of the motor 20 based on the difference evaluation result.

As shown in FIG. 5, the control circuit 100 first executes steps S01, S02, S03, S04, S05, and S06. In step S01, the first search control unit 112 causes the motor 20 to apply a high-frequency search voltage from the power conversion circuit 10. A more detailed procedure of step S01 will be described later. In step S02, the magnetic pole position estimation unit 113 estimates the position of the magnetic pole of the motor 20 based on the search current supplied to the motor 20 in response to the application of the search voltage. In step S03, the condition setting unit 114 sets the pulse supply condition according to the estimation result of the position of the magnetic pole.

In step S04, the second search control unit 115 applies a positive pulse voltage and a negative pulse voltage from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions. A more detailed procedure of step S04 will be described later. In step S05, the difference evaluation unit 116 determines the magnitude of the positive current supplied to the motor 20 in response to the application of the positive pulse voltage and the magnitude of the negative current supplied to the motor 20 in response to the application of the negative pulse voltage. Evaluate the difference (the above response difference). In step S06, the condition changing unit 117 confirms whether or not the evaluation result of the response difference exceeds a predetermined level.

When it is determined in step S06 that the evaluation result of the response difference does not exceed a predetermined level, the control circuit 100 executes step S07. In step S07, the condition changing unit 117 changes the pulse supply condition. After that, the condition changing unit 117 returns the process to step S04. After that, until the evaluation result of the response difference exceeds a predetermined level, the positive pulse voltage and the negative pulse voltage are applied from the power conversion circuit 10 to the motor 20 according to the pulse supply conditions, the response difference is evaluated, and the pulse supply is performed. Changing the conditions is repeated.

When it is determined in step S06 that the evaluation result of the response difference exceeds a predetermined level, the control circuit 100 executes steps S08 and S09. In step S08, the polarity estimation unit 118 estimates the polarity of the magnetic pole 40a based on the evaluation result of the response difference exceeding a predetermined level. In step S09, the drive control unit 121 drives the power conversion circuit 10 to the motor 20 based on the estimation result of the position of the magnetic pole by the magnetic pole position estimation unit 113 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118. Start supplying power. After that, the drive control unit 121 performs magnetic pole position calculation based on the output of the rotation detection sensor or sensorless magnetic pole position estimation, regenerates a voltage command based on the position of the magnetic pole thus obtained, and causes the PWM control unit 111 to generate a voltage command. Repeat the output. As a result, the supply of driving power according to the position of the magnetic pole is continued. This completes the start control procedure for the motor 20.

FIG. 6 is a flowchart illustrating the procedure for applying the search voltage in step S01. As shown in FIG. 6, the control circuit 100 first executes steps S11, S12, and S13. In step S11, the first search control unit 112 starts applying the search voltage from the power conversion circuit 10 to the motor 20. In step S12, the magnetic pole position estimation unit 113 acquires the detection result of the search current from the current sensor 14, and stores the acquired detection result and the phase of the search voltage at that time. In step S13, the first search control unit 112 confirms whether or not the predetermined search period has elapsed.

If it is determined in step S13 that the search period has not elapsed, the control circuit 100 returns the process to step S12. After that, until the search period elapses, the application of the search voltage and the acquisition and storage of the detection result of the search current corresponding to the application are repeated.

If it is determined in step S13 that the search period has elapsed, the control circuit 100 executes step S14. In step S14, the first search control unit 112 stops the application of the search voltage from the power conversion circuit 10 to the motor 20. This completes the procedure for applying the search voltage.

FIG. 7 is a flowchart illustrating the procedure for applying the positive pulse voltage and the negative pulse voltage in step S04. As shown in FIG. 7, the control circuit 100 first executes steps S21, S22, S23, and S24. In step S21, the second search control unit 115 waits for the application time of the positive pulse voltage. In step S22, the second search control unit 115 starts applying a positive pulse voltage from the power conversion circuit 10 to the motor 20. In step S23, the difference evaluation unit 116 acquires the positive current detection result from the current sensor 14. In step S24, the second search control unit 115 confirms whether or not the application period of the positive pulse voltage has elapsed.

If it is determined in step S24 that the period for applying the positive pulse voltage has not elapsed, the control circuit 100 returns the process to step S23. After that, until the application period of the positive pulse voltage elapses, the application of the positive pulse voltage and the acquisition of the detection result of the positive current are repeated.

When it is determined in step S24 that the application period of the positive pulse voltage has elapsed, the control circuit 100 executes steps S25, S31, S32, S33, and S34. In step S25, the second search control unit 115 stops the application of the positive pulse voltage from the power conversion circuit 10 to the motor 20. In step S31, the second search control unit 115 waits for the application time of the negative pulse voltage. In step S32, the second search control unit 115 starts applying a negative pulse voltage from the power conversion circuit 10 to the motor 20. In step S33, the difference evaluation unit 116 acquires the detection result of the negative current from the current sensor 14. In step S34, the second search control unit 115 confirms whether or not the application period of the negative pulse voltage has elapsed.

If it is determined in step S34 that the application period of the negative pulse voltage has not elapsed, the control circuit 100 returns the process to step S33. After that, until the application period of the negative pulse voltage elapses, the application of the negative pulse voltage and the acquisition of the detection result of the negative current are repeated.

When it is determined in step S34 that the application period of the negative pulse voltage has elapsed, the control circuit 100 executes step S35. In step S35, the second search control unit 115 stops the application of the negative pulse voltage from the power conversion circuit 10 to the motor 20. This completes the procedure for applying the positive pulse voltage and the negative pulse voltage.

[Effect of this embodiment]
As described above, the power conversion device 1 includes the first search control unit 112 that supplies the search output to the motor 20 from the power conversion circuit 10, and the position of at least one magnetic pole of the motor 20 based on the response to the search output. The magnetic pole position estimation unit 113 that estimates the position of the magnetic pole, the condition setting unit 114 that sets the pulse supply condition according to the estimation result of the magnetic pole position, and the motor 20 from the power conversion circuit 10 to output the positive pulse and the negative pulse according to the pulse supply condition. The second search control unit 115 to be supplied to the system, the difference evaluation unit 116 to evaluate the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output, and the pulse supply condition to be changed and after the change. The second search control unit 115 is supplied with the positive pulse output and the negative pulse output according to the pulse supply condition of the above, and the difference evaluation unit 116 is made to evaluate the difference, which is repeated until the difference evaluation result exceeds a predetermined level. It includes a condition changing unit 117 and a polarity estimation unit 118 that estimates the polarity of at least one magnetic pole of the motor 20 based on the evaluation result of the difference.

In order to prevent the motor 20 from reversing at the time of starting, it is necessary to supply the drive output to the motor 20 with an appropriate vector for the magnetic pole position and polarity. On the other hand, according to the power conversion device 1, when the evaluation result of the difference between the positive pulse output and the negative pulse output does not exceed a predetermined level, the supply of the positive pulse output and the negative pulse output and the above difference. Since the evaluation of is repeated, false detection of polarity based on the difference is suppressed. Therefore, the reversal of the motor 20 due to the false detection of the polarity of the magnetic pole is suppressed, which is effective in suppressing the reversal of the motor 20.

The condition setting unit 114 may set the pulse supply condition so that the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output passes through the position of at least one magnetic pole of the motor 20. In this case, the number of times the positive pulse output and the negative pulse output are supplied can be suppressed more reliably.

The condition changing unit 117 may change the pulse supply condition so as to change the direction of the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output. In this case, the pulse supply conditions can be adjusted quickly.

The motor 20 includes a plurality of coils 33 arranged at a predetermined angle pitch along the rotation direction of the magnetic poles, and the condition changing unit 117 specifies a change angle in the direction of the magnetic flux vector based on the angle pitch, and responds to the change angle. The pulse supply conditions may be changed so as to change the direction of the magnetic flux vector. The difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output can vary depending on which portion of the rotor 40 each coil 33 faces. By changing the direction of the magnetic flux vector based on the angular pitch, the supply current to the coil 33, which is easily affected by the rotor 40, is reduced, while the supply current to the coil 33, which is not easily affected by the rotor 40, is increased, and the pulse supply condition is changed. It can be adjusted quickly.

The condition changing unit 117 may change the pulse supply condition so as to change the direction of the magnetic flux vector at an angle obtained by substantially multiplying the half pitch of the above angle pitch by an odd number. In this case, the pulse supply conditions can be adjusted more quickly.

The magnetic flux position estimation unit 113 further estimates the position of at least the second magnetic flux of the motor 20 based on the relationship between the voltage and the current in the search output, and the condition setting unit 114 supplies positive pulse output and negative pulse output. The pulse supply condition is set so that the generated magnetic flux vector passes through the magnetic pole, and the condition changing unit 117 changes the pulse supply condition so that the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output passes through the second magnetic pole. You may. In this case, the pulse supply conditions can be adjusted quickly.

The condition changing unit 117 may change the pulse supply conditions so as to change the magnitudes of the positive pulse output and the negative pulse output. In this case, the pulse supply conditions can be adjusted quickly.

The condition changing unit 117 may change the pulse supply condition so as to change the width of the positive pulse output and the negative pulse output. In this case, the pulse supply conditions can be adjusted quickly.

FIG. 8 is a schematic diagram showing a modified example of the power conversion device 1. In this modification, the motor 20 has a sensor 21. The sensor 21 detects the displacement of the magnetic poles 40a, 40b, 40c, 40d. Detecting the displacement of the magnetic poles 40a, 40b, 40c, 40d includes detecting the displacement direction of the magnetic poles 40a, 40b, 40c, 40d. Specific examples of the sensor 21 include a pulse generator that outputs a first pulse wave signal and a second pulse wave signal according to the rotation of the rotor 40. The second pulse wave signal is a signal having the same pulse width as the first pulse wave signal and being out of phase with the first pulse wave signal. Based on the first pulse wave signal and the second pulse wave signal, it is detected in which direction the rotor 40 is rotating (in which direction the magnetic poles 40a, 40b, 40c, and 40d are displaced). .. Further, the rotation speed of the rotor 40 (displacement speed of the magnetic poles 40a, 40b, 40c, 40d) is detected based on the frequencies of the first pulse wave signal and the second pulse wave signal. Further, the rotation angle of the rotor 40 (displacement angle of the magnetic poles 40a, 40b, 40c, 40d) is detected based on the count values of the first pulse wave signal and the second pulse wave signal.

The control circuit 100 in this modification has a magnetic pole position estimation unit 131 and a magnetic pole position update unit 132 in place of the magnetic pole position estimation unit 113 described above. Similar to the magnetic pole position estimation unit 113 described above, the magnetic pole position estimation unit 131 estimates the position of the magnetic pole of the motor 20 based on the search current supplied to the motor 20 in response to the application of the search voltage.

The magnetic pole position updating unit 132 updates the estimation result of the magnetic pole position by the magnetic pole position estimation unit 131 based on the detection result by the sensor 21. For example, the magnetic pole position update unit 132 specifies the displacement direction and displacement angle of the magnetic pole based on the first pulse wave signal and the second pulse wave signal output by the sensor 21, and the magnetic pole position update unit 132 determines the displacement direction and displacement angle of the magnetic pole based on the specified displacement direction and displacement angle. Update the position estimation result. In this way, the magnetic pole position updating unit 132 updates the estimation result of the magnetic pole position by the magnetic pole position estimation unit 131, so that the information on the current position of the magnetic pole continues even after the magnetic pole position estimation unit 131 estimates the magnetic pole position. Can be obtained.

The drive control unit 121 supplies drive power from the power conversion circuit 10 to the motor 20 based on the estimation result of the position of the magnetic pole updated by the magnetic pole position update unit 132 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118. Supply. For example, the drive control unit 121 identifies the position of the positive magnetic pole based on the estimation result of the position of the magnetic pole updated by the magnetic pole position update unit 132 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118, and rotates. The voltage command vector in the above-mentioned fixed coordinate system is calculated based on the voltage command in the coordinate system and the position of the positive magnetic pole.

The control circuit 100 in this modification further includes an error detection unit 133. The error detection unit 133 detects an error in estimating the polarity of the magnetic poles based on the change direction of the position of the magnetic poles detected by the sensor 21 according to the supply of the driving power. For example, the error detection unit 133 detects an error in estimating the polarity of the magnetic pole when the position of the magnetic pole changes in the direction opposite to the rotation direction of the rotating magnetic field generated according to the driving power.

The polarity estimation unit 118 may invert the estimation result of the polarity of the magnetic pole when the estimation error is detected by the error detection unit 133. For example, the polarity estimation unit 118 may shift the position of the positive magnetic pole by 180 ° by the electric angle. When the positive pole is shifted by 180 ° by the electric angle, the polarity of the position that has been regarded as the positive pole up to that point is reversed. Therefore, shifting the position of the positive magnetic pole by 180 ° corresponds to an example of determining the estimation result of the polarity of the magnetic pole. After that, the drive control unit 121 causes the motor 20 to supply the drive power from the power conversion circuit 10 based on the position of the positive magnetic pole after the shift. In this case, the polarity estimation unit 118 may gradually shift the position of the positive magnetic pole over a predetermined period.

Further, the polarity estimation unit 118 may respecify the position that has been regarded as the positive magnetic pole as the position of the magnetic pole that creates the magnetic flux in the direction opposite to the magnetic flux vector MV1. Hereinafter, the magnetic pole that creates the magnetic flux in the direction opposite to the magnetic flux vector MV1 is referred to as a "negative magnetic pole". In this case, the drive control unit 121 may invert the codes of the d-axis current command value, the q-axis current command value, and the V / f voltage command value in order to change the control for the positive magnetic pole to the control for the negative magnetic pole. good. In this case, the drive control unit 121 may gradually invert the values of the d-axis current command value, the q-axis current command value, and the V / f voltage command value toward the values after sign inversion over a predetermined period. good.

The control circuit 100 in this modification executes, for example, the procedure shown in FIG. 9 after starting the drive control in step S09 of FIG. For example, the control circuit 100 first executes step S41. In step S41, the magnetic pole position updating unit 132 updates the estimation result of the magnetic pole position by the magnetic pole position estimation unit 131 based on the detection result by the sensor 21.

Next, the control circuit 100 executes step S42. In step S42, the error detection unit 133 confirms whether or not the position of the magnetic pole has changed in the direction opposite to the rotation direction of the rotating magnetic field generated according to the driving power. When it is determined in step S42 that the position of the magnetic pole changes in the direction opposite to the rotation direction of the rotating magnetic field, the control circuit 100 executes steps S43, S44, S45, and S46.

In step S43, the error detection unit 133 detects an error in estimating the polarity of the magnetic pole. In step S44, the drive control unit 121 stops the supply of drive power from the power conversion circuit 10 to the motor 20. In step S45, the polarity estimation unit 118 inverts the estimation result of the polarity of the magnetic pole. In step S46, the drive control unit 121 restarts the supply of drive power from the power conversion circuit 10 to the motor 20 based on the polarity of the inverted magnetic poles.

As shown above, the power conversion device 1 according to this modification has a magnetic pole position updating unit 132 that updates the estimation result of the magnetic pole position by the magnetic pole position estimation unit 131 based on the detection result by the sensor 21, and the magnetic pole. A drive control unit 121 that supplies drive power from the power conversion circuit 10 to the motor 20 based on the estimation result of the position of the magnetic pole updated by the position update unit 132 and the estimation result of the polarity of the magnetic pole by the polarity estimation unit 118. It is provided with an error detection unit 133 that detects an error in estimating the polarity of the magnetic poles based on the change direction of the position of the magnetic poles detected by the sensor 21 according to the supply of the driving power. As a result, it is possible to quickly detect an error in estimating the polarity of the magnetic pole and reduce its influence.

The polarity estimation unit 118 may invert the estimation result of the polarity of the magnetic pole when the estimation error is detected by the error detection unit 133. In this case, the operation of the motor 20 is quickly normalized based on the magnetic pole position continuously tracked by the magnetic pole position update unit 132 and the estimation result of the polarity of the magnetic pole inverted by the polarity estimation unit 118. Can be done.

When the magnetic pole position updating unit 132 and the error detecting unit 133 are further provided, as described above, the estimation error can be quickly detected and the operation of the motor 20 can be quickly normalized, so that the condition changing unit can be provided. 117 may be omitted, and the polarity estimation unit 118 may estimate the polarity of the magnetic pole based on the difference evaluation result regardless of whether or not the difference evaluation result exceeds a predetermined level.

Although the embodiments have been described above, the present disclosure is not necessarily limited to the above-described embodiments, and various changes can be made without departing from the gist thereof.

1 ... Power conversion device, 10 ... Power conversion circuit, 20 ... Motor (motor), 112 ... First search control unit, 113 ... Magnetic pole position estimation unit, 114 ... Condition setting unit, 115 ... Second search control unit, 116 ... Difference evaluation unit, 117 ... condition change unit, 118 ... polarity estimation unit.

Claims (16)

The first search control unit that supplies the search output from the power conversion circuit to the motor,
A magnetic pole position estimation unit that estimates the position of the magnetic pole of the motor based on the response to the search output, and a magnetic pole position estimation unit.
A condition setting unit that sets pulse supply conditions according to the estimation result of the position of the magnetic pole, and a condition setting unit.
A second search control unit that supplies positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
A difference evaluation unit that evaluates the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
The pulse supply condition is changed, the second search control unit is supplied with the positive pulse output and the negative pulse output according to the changed pulse supply condition, and the difference evaluation unit is made to evaluate the difference. A condition change unit that repeats this until the evaluation result of the difference exceeds a predetermined level.
A power conversion device including a polarity estimation unit that estimates the polarity of the magnetic pole based on the evaluation result of the difference. The power conversion device according to claim 1, wherein the condition setting unit sets the pulse supply condition so that the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output passes through the magnetic pole. The power conversion device according to claim 2, wherein the condition changing unit changes the pulse supply conditions so as to change the direction of the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output. The motor includes a plurality of coils arranged at a predetermined angular pitch along the rotation direction of the magnetic poles.
The condition changing unit specifies the change angle of the direction of the magnetic flux vector based on the angle pitch, and changes the pulse supply condition so as to change the direction of the magnetic flux vector according to the change angle. The power conversion device according to claim 3, wherein the supply conditions are changed. The power conversion device according to claim 4, wherein the condition changing unit changes the pulse supply condition so as to change the direction of the magnetic flux vector substantially at an angle obtained by multiplying a half pitch of the angle pitch by an odd number. The magnetic pole position estimation unit further estimates the position of the second magnetic pole of the motor based on the relationship between the voltage and the current in the search output.
The condition setting unit sets the pulse supply condition so that the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output passes through the magnetic pole.
The power conversion device according to claim 3, wherein the condition changing unit changes the pulse supply condition so that the magnetic flux vector generated by the supply of the positive pulse output and the negative pulse output passes through the second magnetic pole. The power conversion device according to any one of claims 2 to 4, wherein the condition changing unit changes the pulse supply conditions so as to change the magnitudes of the positive pulse output and the negative pulse output. The power conversion device according to any one of claims 2 to 5, wherein the condition changing unit changes the pulse supply conditions so as to change the width of the positive pulse output and the negative pulse output. The motor further comprises a sensor that detects a change in the position of the magnetic pole.
The power converter is
A magnetic pole position update unit that updates the estimation result of the position of the magnetic pole by the magnetic pole position estimation unit based on the detection result by the sensor, and a magnetic pole position update unit.
Drive control for supplying drive power from the power conversion circuit to the motor based on the estimation result of the position of the magnetic pole updated by the magnetic pole position update unit and the estimation result of the polarity of the magnetic pole by the polarity estimation unit. Department and
Claims 1 to 8 further include an error detecting unit that detects an error in estimating the polarity of the magnetic pole based on the change direction of the position of the magnetic pole detected by the sensor according to the supply of the driving power. The power conversion device according to any one of the above. The power conversion device according to claim 9, wherein the polarity estimation unit inverts the estimation result of the polarity of the magnetic pole when the estimation error is detected by the error detection unit. A first search control unit that supplies a search output from a power conversion circuit to an electric motor that has a sensor that detects changes in the position of the magnetic poles.
A magnetic pole position estimation unit that estimates the position of the magnetic pole of the motor based on the response to the search output, and a magnetic pole position estimation unit.
A condition setting unit that sets pulse supply conditions according to the estimation result of the position of the magnetic pole, and a condition setting unit.
A second search control unit that supplies positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
A difference evaluation unit that evaluates the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
A polarity estimation unit that estimates the polarity of the magnetic pole based on the evaluation result of the difference,
A magnetic pole position update unit that updates the estimation result of the position of the magnetic pole by the magnetic pole position estimation unit based on the detection result by the sensor, and a magnetic pole position update unit.
Drive control for supplying drive power from the power conversion circuit to the motor based on the estimation result of the position of the magnetic pole updated by the magnetic pole position update unit and the estimation result of the polarity of the magnetic pole by the polarity estimation unit. Department and
A power conversion device including an error detecting unit that detects an error in estimating the polarity of the magnetic pole based on the change direction of the position of the magnetic pole detected by the sensor according to the supply of the driving power. The power conversion device according to claim 9, wherein the polarity estimation unit inverts the estimation result of the polarity of the magnetic poles of the magnetic poles when the estimation error is detected by the error detection unit. To supply the search output to the motor from the power conversion circuit,
Estimating the position of the magnetic pole of the motor based on the response to the search output,
Setting the pulse supply conditions according to the estimation result of the position of the magnetic pole, and
To supply positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
To evaluate the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
Changing the pulse supply condition, supplying the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the changed pulse supply condition, and evaluating the difference. Repeating until the evaluation result of the difference exceeds a predetermined level,
A control method including estimating the polarity of the magnetic pole based on the evaluation result of the difference. To supply a search output from a power conversion circuit to an electric motor having a sensor that detects a change in the position of a magnetic pole.
To estimate the position of the magnetic pole of the motor based on the response to the search output,
Setting the pulse supply conditions according to the estimation result of the position of the magnetic pole, and
To supply positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
To evaluate the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
Estimating the polarity of the magnetic pole based on the evaluation result of the difference,
Updating the estimation result of the position of the magnetic pole based on the detection result by the sensor, and
Based on the updated estimation result of the position of the magnetic pole and the estimation result of the polarity of the magnetic pole, the power conversion circuit supplies the driving power to the motor.
A control method comprising detecting an error in estimating the polarity of the magnetic pole based on a change direction of the position of the magnetic pole detected by the sensor according to the supply of the driving power. To supply the search output to the motor from the power conversion circuit,
Estimating the position of the magnetic pole of the motor based on the response to the search output,
Setting the pulse supply conditions according to the estimation result of the position of the magnetic pole, and
To supply positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
To evaluate the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
Changing the pulse supply condition, supplying the positive pulse output and the negative pulse output from the power conversion circuit to the motor according to the changed pulse supply condition, and evaluating the difference. Repeating until the evaluation result of the difference exceeds a predetermined level,
A program for causing an apparatus to estimate the polarity of the magnetic pole based on the evaluation result of the difference. To supply a search output from a power conversion circuit to an electric motor having a sensor that detects a change in the position of a magnetic pole.
Estimating the position of the magnetic pole of the motor based on the response to the search output,
Setting the pulse supply conditions according to the estimation result of the position of the magnetic pole, and
To supply positive pulse output and negative pulse output from the power conversion circuit to the motor according to the pulse supply conditions.
To evaluate the difference between the magnitude of the response to the positive pulse output and the magnitude of the response to the negative pulse output.
Estimating the polarity of the magnetic pole based on the evaluation result of the difference,
Updating the estimation result of the position of the magnetic pole based on the detection result by the sensor, and
Based on the updated estimation result of the position of the magnetic pole and the estimation result of the polarity of the magnetic pole, the power conversion circuit supplies the driving power to the motor.
A program for causing an apparatus to detect an error in estimating the polarity of the magnetic pole based on the change direction of the position of the magnetic pole detected by the sensor according to the supply of the driving power.

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