JP5351246B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device having a power monitoring function.

  In recent years, production factories are required to more precisely manage power consumption in factories. For this reason, the power consumption of the machine tool installed in the production factory is individually monitored. For example, in an electric injection molding machine or a machine tool, a power monitor function is provided in a motor control device that controls the operation of the machine in order to grasp the power consumption of the machine.

  A motor control device used for an electric injection molding machine or the like generally includes a converter that rectifies an alternating current and a plurality of inverters that drive the motor. As a method of monitoring the power consumption amount by the motor control device, for example, there are the following first to fourth methods.

  First, the first method is a method in which a wattmeter is provided in the motor control device and the power consumption of the machine tool is grasped by the wattmeter.

  Next, as disclosed in Patent Document 1 below, the second method obtains each of the motor power consumption, the loss power of the amplifier driving the motor, and the fixed power consumption of the machine tool by calculation. In this method, each power is integrated over time and the power consumption of the machine tool is grasped.

  As disclosed in Patent Document 2 below, the third method detects the voltage value and current value between the converter and the inverter, and integrates the power calculated based on the detected voltage value and current value over time. This is a method for grasping the power consumption of the machine tool.

  Finally, as disclosed in Patent Document 3 below, the fourth method detects a voltage value and a current value between the three-phase AC power supply side and the PWM converter, and based on the detected voltage value and current value. This is a method of calculating the power consumption and regenerative power to grasp the power consumption of the machine tool.

JP 2010-115063 A JP 2002-192588 A JP 2010-110936 A

  However, in the case of the first method, since it is necessary to separately provide a wattmeter, the number of parts and the cost of the parts constituting the motor control device increase.

  In the case of the second method, many parameters such as motor torque constant, motor winding resistance value, and amplifier power loss coefficient are obtained and stored in order to obtain power consumption such as motor power consumption and amplifier loss power. It is necessary to keep. Further, when a plurality of inverters are connected to the converter and there are a plurality of types of motors connected to the inverters, it is necessary to obtain and store individual parameters for each motor. On the other hand, since the iron loss and mechanical loss of the motor are not taken into account, it cannot be said that the power consumption detection accuracy is high.

  In the case of the third method, a detector for detecting a voltage value and a current value between the converter and the inverter is required. Generally, a converter that only rectifies is not provided with a detector that detects current. For this reason, since it is necessary to separately provide a detector for detecting current, the number of parts and the cost of parts constituting the motor control device are increased.

  In the case of the fourth method, a general 120 ° energizing power regeneration converter is not provided with a detector for detecting a three-phase AC voltage for cost reduction. For this reason, since it is necessary to provide the detector which detects a three-phase alternating current voltage separately, the number of parts of the components which comprise a motor control apparatus, and cost increase.

  The present invention has been made in order to solve the conventional problems as described above, and is provided with a special detector for calculating electric power without using many parameters such as motor constants. It is an object of the present invention to provide a motor control device having a power monitoring function that can monitor power consumption using an existing detector provided for converter control in a 120 ° energizing power regeneration converter. .

  A motor control device according to the present invention for solving the above-described problems includes a converter unit connected to a multiphase power source and an inverter unit connected to the motor, and the converter unit and the inverter unit cooperate to provide a motor control device. This is a motor control device that controls power running and regeneration.

  The motor control device includes a phase detection circuit, a selector circuit, an averaging circuit, a coefficient multiplication circuit, a power calculation circuit, and an integrated power circuit. The phase detection circuit, the selector circuit, and the averaging circuit use existing circuits that are provided for controlling the power running and regeneration of the converter.

  The phase detection circuit detects the phase of the multiphase AC voltage of the multiphase power supply. The selector circuit selects an alternating current of a specific phase from the phase detected by the phase detection circuit and converts it into a direct current. The averaging circuit averages the direct current converted by the selector circuit to obtain an average direct current. By the operations of the selector circuit and the averaging circuit, the average DC current can be obtained from the AC current of a specific phase selected based on the phase of the multiphase AC voltage.

  The coefficient multiplication circuit multiplies the average direct current obtained by the averaging circuit by a coefficient. The power calculation circuit calculates power by multiplying the average DC current multiplied by the coefficient by the coefficient multiplication circuit and the DC voltage on the load side of the converter unit. The integrated power circuit calculates the integrated power by integrating the power calculated by the power calculation circuit with time.

  According to the present invention configured as described above, the average DC current supplied from the multiphase AC power source is obtained using the existing phase detection circuit, selector circuit, and averaging circuit, and the obtained average DC current and the converter unit The integrated power can be obtained using the DC voltage on the load side.

  Therefore, without using many parameters such as motor constants, and without providing a special detector for calculating electric power, the existing detector provided for converter control is used. Power can be monitored.

It is a block diagram of the motor control device concerning this embodiment. It is a wave form diagram with which it uses for operation | movement description of the motor control apparatus shown in FIG. It is a wave form diagram with which it uses for operation | movement description of the motor control apparatus shown in FIG.

  Below, the motor control apparatus which concerns on this embodiment is demonstrated. FIG. 1 is a block diagram of a motor control device according to the present embodiment.

[Configuration of motor controller]
The motor control device 100 includes a reactor 10R, 10S, 10T, a converter unit 20, a capacitor 25, and an inverter unit 30 in order to supply electric power to the motor 300.

  Reactors 10R, 10S, and 10T are connected in series between three-phase power supply 200 and converter unit 20 to three-phase power supply lines R, S, and T that connect three-phase power supply 200 and converter unit 20, respectively. Reactors 10R, 10S, and 10T adjust currents flowing through three-phase power supply lines R, S, and T, respectively.

  Converter unit 20 converts alternating current from three-phase power supply 200 into direct current. The converter unit 20 is configured by bridge-connecting six semiconductor switching elements. The semiconductor switching element includes an insulated gate bipolar transistor 20A called an IGBT and a diode 20D. Diode 20D is connected between the collector and emitter of insulated gate bipolar transistor 20A. Each diode 20D is connected in such a polarity that the three-phase alternating current is full-wave rectified to direct current when the motor 300 is powered, but the regenerative current does not flow. The semiconductor switching element may be an IPM in which a protection circuit is attached to the IGBT instead of the IGBT.

  The capacitor 25 is an electrolytic capacitor having a large capacity, and smoothes the direct current output from the converter unit 20.

  The inverter unit 30 converts the direct current output from the converter unit 20 into alternating current and supplies it to the motor 300. Similarly to the converter unit 20, the inverter unit 30 is configured by bridge-connecting six semiconductor switching elements. The semiconductor switching element includes an insulated gate bipolar transistor 30A called an IGBT and a diode 30D. Diode 30D is connected between the collector and emitter of insulated gate bipolar transistor 30A. Each diode 30 </ b> D is connected in such a polarity that the alternating current generated by the motor 300 can be rectified into direct current when the motor 300 is regenerated.

  The motor control device 100 generally operates as follows when the motor 300 is powered and regenerated.

  When powering the motor 300, the alternating current supplied from the three-phase power source 200 is once converted into a direct current by the converter unit 20, and is converted into a substantially complete direct current by the capacitor 25. Further, the direct current is converted into an alternating current having a desired frequency and voltage by the inverter unit 30, and the motor 300 is powered by the alternating current.

  On the other hand, when the current generated by the motor 300 is regenerated, the alternating current generated by the motor 300 is converted into a direct current by the inverter unit 30. Further, the direct current is converted into alternating current of commercial frequency and voltage by the converter unit 20 and regenerated toward the three-phase power source 200.

  In the present embodiment, regeneration of the current generated by the motor 300 is performed by conducting the six semiconductor switching elements included in the converter unit 20 in the 120 ° conduction mode.

  The motor control device 100 adjusts the current at the time of regeneration and power running of the motor 300 by controlling the switching of the insulated gate bipolar transistors 20A and 30A of the converter unit 20 and the inverter unit 30.

  In order to control the switching of the insulated gate bipolar transistors 20A and 30A, the motor control device 100 includes a phase detection circuit 35, a current selection signal generation circuit 40, current detectors 45R and 45S, a selector circuit 50, an edge detection circuit 55, an average A circuit 60, a polarity determination circuit 65, a stop signal generation circuit 70, a power supply voltage peak value detection circuit 75, a regeneration start detection circuit 80, and a gate signal generation circuit 85.

  The phase detection circuit 35 detects the phase of the three-phase AC voltage applied to the three-phase power supply lines R, S, T, and outputs a phase signal S4 corresponding to the change in the phase of the three-phase AC voltage.

  The current selection signal generation circuit 40 generates a current selection signal S3 based on the phase signal S4 output from the phase detection circuit 35. The current selection signal S3 is a signal for selecting an alternating current of a specific phase from the alternating current for three phases.

  The current detectors 45R and 45S detect a two-phase alternating current flowing through the three-phase power supply lines R and S. The current flowing in the T phase is obtained by calculation from a two-phase alternating current.

  The selector circuit 50 is detected by the current detectors 45R and 45S based on the current selection signal S3 generated by the current selection signal generation circuit 40, and further, from the three-phase AC current obtained by calculation, the R phase and S phase. , T phase, -R phase, -S phase, and -T phase are selected. Therefore, selection of the alternating current by the selector circuit 50 is equivalent to performing alternating current-direct current conversion on the alternating current supplied from the three-phase power source 200. Therefore, an alternating current can be converted into a direct current with a simple configuration of the selector circuit 50.

  The edge detection circuit 55 detects an edge of the current selection signal S3, and outputs a timing signal by detecting the edge. In this embodiment, the edge of the current selection signal S3 is detected, but the edge of the phase signal S4 output from the phase detection circuit 35 may be detected and a timing signal may be output.

  The averaging circuit 60 averages the current values selected by the selector circuit 50 based on the timing signal output from the edge detection circuit 55 to obtain an average direct current. Therefore, the averaging circuit 60 sequentially averages the AC currents of the R phase, S phase, T phase, -R phase, -S phase, and -T phase.

  Note that the phase detection circuit 35, the current selection signal generation circuit 40, the current detectors 45R and 45S, the selector circuit 50, the edge detection circuit 55, and the averaging circuit 60 are provided in the motor control device 100 in order to control the converter. The circuit that had been used is used.

  The polarity determination circuit 65 determines whether the average DC current value output from the averaging circuit 60 is 0, or whether the polarity of the average DC current has changed from + to-or from-to +. It is determined whether or not 300 has shifted from power running to regeneration and from regeneration to power running.

  The stop signal generation circuit 70 outputs a stop signal S2 when the polarity determination circuit 65 indicates that the determination has shifted from regeneration to power running.

  The power supply voltage peak value detection circuit 75 performs full-wave rectification on the three-phase AC voltage applied to the three-phase power supply lines R, S, and T, and detects the peak value of the power supply voltage after full-wave rectification.

  Regeneration start detection circuit 80 compares the DC voltage output from converter unit 20 with the peak value of the power supply voltage after full-wave rectification detected by power supply voltage peak value detection circuit 75. When the DC voltage output from converter unit 20 is about 15 V higher than the peak value of the power supply voltage after full-wave rectification, regeneration start detection circuit 80 determines that the regeneration state has been entered and outputs regeneration start signal S1.

  The gate signal generation circuit 85 outputs a gate signal S5 to the insulated gate bipolar transistor 20A that constitutes the converter unit 20 based on the phase signal S4 output from the phase detection circuit 35. Further, the gate signal generation circuit 85 outputs the gate signal S5 to the insulated gate bipolar transistor 20A based on the regeneration start signal S1 output from the regeneration start detection circuit 80. Further, the gate signal generation circuit 85 stops the output of the gate signal S5 based on the stop signal S2 output from the stop signal generation circuit 70.

  The motor control device 100 operates the converter unit 20 in the AC-DC conversion mode when the motor 300 is powering. On the other hand, when motor 300 is in a regenerative state, motor control device 100 causes converter unit 20 to operate in a DC-AC conversion mode.

  The regeneration start detection circuit 80 detects that the regeneration state has been reached. In the regenerative state, the gate signal S5 is output from the gate signal generation circuit 85 to the converter unit 20. The converter unit 20 is controlled by the gate signal S5, and the insulated gate bipolar transistor 20A is energized for a 120 ° interval according to the power supply phase timing. So-called 120 ° energization power regeneration control is performed. The power generated by the motor 300 is regenerated in the three-phase power source 200 by the power regeneration control.

  When motor 300 shifts from the regenerative state to the power running state (including the end of the regenerative state), motor control device 100 causes converter unit 20 to operate again in the AC-DC conversion mode. The polarity determination circuit 65 detects that the power running state has been reached. When it is detected that the power running state is reached, the stop signal generation circuit 70 outputs the stop signal S2, so that the gate signal S5 is not output from the gate signal generation circuit 85, and the power regeneration is stopped.

  The motor control device 100 includes a coefficient multiplication circuit 110, a power calculation circuit 120, a filter circuit 130, and an integrated power circuit 140 in order to monitor the power consumption of the motor control device 100 and the motor 300.

  Coefficient multiplication circuit 110 multiplies the DC current averaged by averaging circuit 60 by a set coefficient to estimate the DC current value output from converter 20. The coefficient set in the coefficient multiplication circuit 110 has different values when the motor 300 is in powering mode and during regeneration. Coefficients during power running and regeneration are measured in actual use conditions, and the measured values are set. Since the loss of converter 20 is proportional to the magnitude of the direct current, the coefficient may be set in consideration of the loss of converter 20. This is because more accurate power consumption can be calculated.

  Power calculation circuit 120 calculates power by multiplying the DC current estimated by coefficient multiplication circuit 110 and the DC voltage of converter 20.

  The filter circuit 130 is a low-pass filter that cuts a high-frequency component of the power waveform calculated by the power calculation circuit 120.

  The integrated power circuit 140 integrates with time the noise-free power waveform that has passed through the filter 130, the amount of power supplied to the motor 300 by the motor control device 100, the amount of power regenerated from the motor 300, and consumed by the motor control device 100 itself. The integrated power amount obtained by summing the calculated power amounts is calculated. The calculated integrated power amount is output to an external device.

  The three-phase power supply voltage of the three-phase power supply 200 is full-wave rectified to calculate the average value of the power supply voltage, the average value of the power supply voltage is multiplied by a coefficient, and the averaged DC current is multiplied by the coefficient. The average power may be calculated through the filter circuit 130.

  Further, the reactors 10R, 10S, and 10T may be disposed closer to the power source than the current detectors 45R and 45S. In the present embodiment, one inverter unit 30 is connected to one converter unit 20, but even if a plurality of inverter units 30 are connected to one converter unit 20, power consumption is calculated. Is possible.

  Motor control device 100 detects a current flowing through three-phase power supply 200, multiplies the detected current by a coefficient to estimate a DC current value output from converter unit 20, and outputs the output of converter unit 20 to the estimated DC current value. Multiply the voltage to calculate the average power. And the exact power consumption is calculated | required by integrating the calculated average electric power by time.

  In addition, each circuit which comprises the motor control apparatus 100 of this embodiment may be comprised with a hardware, and may be formed inside a microcomputer etc. using software.

[Operation of motor controller]
Next, a specific operation of the motor control device 100 will be described with reference to FIGS. 2 and 3 are waveform diagrams for explaining the operation of the motor control device shown in FIG.

  The waveforms shown in FIG. 2A are power supply voltages VR, VS, and VT applied by the three-phase power supply 200 to the three-phase power supply lines R, S, and T, respectively. The power supply voltages VR, VS, and VT have the same voltage waveform and their phases are shifted by 120 °.

  FIG. 2B shows the phase signal S4 output from the phase detection circuit 35 of FIG. The phase detection circuit 35 compares the power supply voltages VR, VS, and VT of the three-phase power supply lines R, S, and T, and outputs phase signals PR1, PS1, PT1, PR2, PS2, and PT2.

  The power supply voltage VR is compared with the power supply voltage VS or the power supply voltage VT. When the power supply voltage VR is higher than the power supply voltage VS or the power supply voltage VT, the phase signal PR1 becomes HI, and the power supply voltage VR becomes the power supply voltage VS. Alternatively, the phase signal PR1 becomes LOW when it is smaller than the power supply voltage VT. When the power supply voltage VS is higher than the power supply voltage VR or the power supply voltage VT, the phase signal PS1 becomes HI, and when the power supply voltage VS is lower than the power supply voltage VR or the power supply voltage VT, the phase signal PS1 becomes LOW. When the power supply voltage VT is higher than the power supply voltage VR or the power supply voltage VS, the phase signal PT1 becomes HI, and when the power supply voltage VT is lower than the power supply voltage VR or the power supply voltage VS, the phase signal PT1 becomes LOW.

  The power supply voltage VR is compared with the power supply voltage VS or the power supply voltage VT. When the power supply voltage VR is lower than the power supply voltage VS or the power supply voltage VT, the phase signal PR2 becomes HI, and the power supply voltage VR becomes the power supply voltage VS. Alternatively, the phase signal PR2 becomes LOW when it is larger than the power supply voltage VT. When the power supply voltage VS is lower than the power supply voltage VR or the power supply voltage VT, the phase signal PS2 becomes HI, and when the power supply voltage VS is higher than the power supply voltage VR or the power supply voltage VT, the phase signal PS2 becomes LOW. When the power supply voltage VT is lower than the power supply voltage VR or the power supply voltage VS, the phase signal PT2 becomes HI, and when the power supply voltage VT is higher than the power supply voltage VR or the power supply voltage VS, the phase signal PT2 becomes LOW.

  Therefore, the phase signals PR1, PS1, and PT1 represent sections where the power supply voltage of each phase is larger than the voltage of the other phase, and the phase signals PR2, PS2, and PT2 are voltages of the power supply voltage of each phase of the other phase. It represents a larger section on the minus side.

  When the motor 300 is powered, the three-phase AC power from the three-phase power source 200 is rectified by the free wheel diode 20D of the converter unit 20, and the rectified DC power is output to the capacitor 25 and the inverter unit 30 to be converted into AC power. The motor 300 is driven. When the motor 300 is accelerated, the DC voltage output from the converter unit 20 gradually decreases as shown in FIG. 3A, and the average DC current output from the averaging circuit 60 gradually increases. Thereafter, when the motor 300 enters a constant speed state, the value of the average DC current becomes constant. The operation for obtaining the average DC current value will be described later. During the power running of the motor 300, the gate signal generation circuit 85 stops operating.

  During regeneration of the motor 300, the DC voltage output from the converter unit 20 gradually increases as shown in FIG. The DC voltage output from converter unit 20 becomes higher than the peak value of the power supply voltage detected by power supply voltage peak value detection circuit 75. The regeneration start detection circuit 80 outputs a regeneration start signal S1.

  When the regeneration start signal S1 is input to the gate signal creation circuit 85, the gate signal creation circuit 85 creates the gate signal S5 based on the phase signals PR1, PS1, PT1, PR2, PS2, and PT2. The created gate signal S5 is output to the converter unit 20.

  The six transistors 20A of the converter unit 20 conduct in a 120 ° conduction mode according to the gate signal S5, and regenerate the regenerative power to the three-phase power source 200.

  FIG. 2C shows the contents of the current selection signal S3 created by the current selection signal creation circuit 40. In FIG. 2C, S, R, T, and -S, -R, -T are used to select IR, IS, IT of the current flowing through the three-phase power supply lines R, S, T and their inverted signals, respectively. Means that.

  The current IR, IS, IT of each phase flowing through the three-phase power supply lines R, S, T shown in FIG. 2D is regenerated to the three-phase power supply 200 side by the converter unit 20 in the 120 ° conduction mode. Therefore, the currents IR, IS, and IT are flown by 120 ° each in electrical angle.

  For example, the current selection signal “-S” in FIG. 2C indicates that the current IS flowing through the three-phase power supply line S is selected, and the selector circuit 50 outputs the polarity inversion signal of this current. Further, the current selection signal “R” in FIG. 2C indicates that the current IR flowing through the three-phase power supply line R is selected, and the selector circuit 50 outputs this current as it is. The current selection signal “−T” in FIG. 2C indicates that the current IT flowing through the three-phase power supply line T is selected, and the selector circuit 50 outputs the polarity inversion signal of this current. The items indicated by the current selection signals “S”, “−R”, and “T” are the same as the items indicated by the current selection signals “R” and “−T”.

  FIG. 2E shows a current selection output in which the currents selected by the selector circuit 50 are arranged in time series. When the selector circuit 50 selects currents for three phases, the averaging circuit 60 averages and outputs the currents for the three phases.

  FIG. 2F shows the waveform of the average direct current output from the averaging circuit 60. The averaging circuit 60 performs an averaging process every time the input of the current values for the three phases is completed, and the value of the average direct current changes stepwise according to the change of the current value.

  FIG. 3B shows a change in average DC current when the length of the time axis is made shorter than that in FIG. Since a current flows from the motor 300 side to the three-phase AC power source 200 side during the regeneration period, the current selection signal S3 is generated so that, for example, a positive average DC current value is output in the powering state. The average direct current value during regeneration is negative. When the rotational speed of the motor 300 decreases and the regenerative power decreases, the average direct current value also decreases accordingly.

  Theoretically, it can be determined that regeneration has ended when the value of the average DC current becomes “0”. However, the change in the current in the vicinity where the average DC current value is “0” is unstable and easy to make an erroneous determination. Therefore, in the present embodiment, whether or not the state has changed from regeneration to power running is determined after a certain period of time has elapsed in the polarity determination circuit 65 after the value of the average direct current exceeds a predetermined value and changes toward zero. At this time, the determination is made based on whether the value of the average direct current is 0 or whether the polarity has changed.

  Therefore, in this embodiment, there is little possibility of incorrect determination. When the polarity determination circuit 65 detects that the value of the average direct current becomes 0 or the inversion of the polarity, the stop signal generation circuit 70 generates a stop signal S2.

  When the stop signal S2 is output from the stop signal generation circuit 70, the gate signal generation circuit 85 stops the gate signal generation operation, and the six transistors 20A of the converter unit 20 are turned off. Thereafter, if the inverter unit 30 is operating, DC power is output through a rectifier circuit constituted by the six diodes 20D of the converter unit 20.

  FIG. 3C shows an estimated DC current value of the converter unit 20 obtained by multiplying the average DC current output from the averaging circuit 60 by the coefficient set in the coefficient multiplier circuit 110. During power running of the motor 300, the rising angle of the estimated DC current value in FIG. 3C is larger than the rising angle of the average DC current value in FIG. On the other hand, during regeneration of the motor 300, the rising angle of the average direct current in FIG. 3B is substantially the same as the rising angle of the estimated direct current value in FIG. This is because the coefficient set in the coefficient multiplication circuit 110 is set to a different value when the motor 300 is in power running and during regeneration.

  FIG. 3D shows a waveform of average power obtained after passing through the filter circuit 130. FIG. 3E shows a waveform of the amount of power obtained by integrating the average power with time in the integrated power circuit 140. As is apparent from FIG. 3E, it can be seen that the amount of power increases when the motor 300 is powered and decreases when the motor 300 is regenerated.

By monitoring the amount of power calculated by the integrated power circuit 140, the power consumption of the motor 300 including the motor control device 100 can be easily and accurately grasped at low cost.
The amount of electric power can be easily grasped because it is not necessary to use many parameters such as motor constants. This is because the existing detector provided for the purpose is utilized.

  As described above, according to the motor control device of the present embodiment, the power consumption can be grasped easily and accurately at a low cost.

10R, 10S, 10T reactor,
20 converter unit,
25 capacitors,
30 Inverter unit,
40 Current selection signal generation circuit,
45R, 45S current detector,
50 selector circuit,
55 edge detection circuit,
60 averaging circuit,
65 polarity judgment circuit,
70 Stop signal generation circuit,
75 Power supply voltage peak detection circuit,
80 regeneration start detection circuit,
85 Gate signal generation circuit,
100 motor control device,
110 coefficient multiplication circuit,
120 power calculation circuit,
130 filter circuit,
140 integrated power circuit,
200 Three-phase AC power supply,
300 motor.

Claims (7)

A motor control device comprising a converter unit connected to a multiphase power supply and an inverter unit connected to a motor, wherein the converter unit and the inverter unit cooperate to control power running and regeneration of the motor,
A phase detection circuit for detecting the phase of the multiphase AC voltage of the multiphase power supply;
A selector circuit that selects an alternating current of a specific phase from the phase detected by the phase detection circuit and converts the alternating current into a direct current;
An averaging circuit that averages the direct current converted by the selector circuit to obtain an average direct current;
A coefficient multiplying circuit that multiplies a coefficient by the average direct current obtained by the averaging circuit;
A power calculation circuit that calculates power by multiplying the average DC current multiplied by the coefficient by the coefficient multiplication circuit and the DC voltage on the load side of the converter unit;
An integrated power circuit that calculates the integrated power by integrating the power calculated by the power calculation circuit over time, and
The motor control device according to claim 1, wherein the phase detection circuit, the selector circuit, and the averaging circuit are existing circuits provided to control power running and regeneration of the motor.   The multi-phase power supply is a three-phase power supply, and further includes two current detectors for detecting an alternating current flowing through two phases of the three phases, and an alternating current flowing through the other one of the three phases is The motor control device according to claim 1, wherein the motor control device is obtained by calculation.   3. The motor control device according to claim 2, wherein selection of an alternating current by the selector circuit is equivalent to performing alternating current-direct current conversion on the alternating current supplied from the multiphase power source. A current selection signal generation circuit is provided between the phase detection circuit and the selector circuit,
The current selection signal generation circuit outputs a current selection signal for causing the selector circuit to select an alternating current of a specific phase based on a phase signal output from the phase detection circuit. 4. The motor control device according to any one of 3. An edge detection circuit is provided between the current selection signal generation circuit and the averaging circuit,
The edge detection circuit detects an edge of a current selection signal output from the current selection signal generation circuit, and outputs a timing signal for averaging a direct current to the averaging circuit by detecting the edge. The motor control device according to claim 4.   6. The motor control device according to claim 1, wherein a coefficient used in the coefficient multiplication circuit is different between a power running time and a regeneration time of the motor.   7. The converter unit according to claim 1, wherein the converter unit regenerates electric power generated by the motor to the multi-phase power source by conducting a semiconductor switching element included in the converter unit in a 120 ° conduction mode. The motor control apparatus in any one.

Images