JP7018367B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device, for example, a power conversion device that supplies electric power to a motor.

Patent Document 1 discloses a motor control device including an inverter circuit for controlling a motor and a boost converter for supplying power to the inverter circuit. In the motor control device, in order to reduce the processing load associated with the energization control of the motor, the torque command from the torque command calculation unit and the counter electromotive voltage from the counter electromotive voltage calculation unit are input, and the boost voltage is boosted based on a predetermined map. A boosted voltage command calculation unit for calculating commands is provided. In the predetermined map, the relationship between the torque command, the counter electromotive voltage, and the boost voltage command is determined in advance so that the motor has the maximum efficiency.

Japanese Unexamined Patent Publication No. 2009-65758

For example, in industrial equipment, automobile equipment, train equipment, elevator equipment, and the like, a power conversion device that converts an input voltage into a voltage required by a load (specifically, a motor) is used. Such a power conversion device includes, for example, a power unit circuit that converts an input voltage into a DC power supply voltage, and an amplifier circuit that supplies power to a motor using the DC power supply voltage. The power unit circuit and the amplifier circuit are usually composed of a switching circuit using a switching element in order to improve efficiency and reduce the cost.

Here, during steady rotation of the motor, the amplifier circuit supplies stable power to the motor, and the power unit circuit also outputs a stable DC power supply voltage to the amplifier circuit. However, for example, when the motor is started or when high pressurization is started, the load suddenly becomes heavy, so that a large voltage drop may occur in the DC power supply voltage from the power unit circuit. Increasing the control band of the power unit circuit makes it possible to respond to such load fluctuations at high speed, but usually the control band can only be increased to a certain level.

The present invention has been made in view of the above, and one of the objects thereof is to provide a power conversion device capable of responding to load fluctuations at high speed.

The above and other objects and novel features of the invention will become apparent from the description and accompanying drawings herein.

The following is a brief description of the outline of typical embodiments disclosed in the present application.

A power conversion device according to a typical embodiment of the present invention includes an amplifier circuit, an amplifier control unit, a power unit circuit, and a power unit control unit. The amplifier circuit includes a plurality of first switching elements to supply power to the motor. The amplifier control unit switches and controls a plurality of first switching elements. The power unit circuit includes a reactor and a second switching element, and converts an input voltage into an output voltage that becomes a power supply voltage of the amplifier circuit. The power unit control unit includes a current command value calculation unit, and switches and controls the second switching element. The current command value calculation unit calculates the current command value for the power unit circuit by an arithmetic formula including the angular velocity and torque value of the motor and the input voltage or output voltage value of the power unit circuit as parameters.

Briefly explaining the effects obtained by the typical embodiments among the inventions disclosed in the present application, it becomes possible to respond to load fluctuations at high speed.

It is a schematic diagram which shows the structural example of the power conversion apparatus according to Embodiment 1 of this invention. It is a waveform diagram which shows the operation example of the main part in the power conversion apparatus of FIG. It is a schematic diagram which shows the structural example of the power conversion apparatus according to Embodiment 2 of this invention. It is a schematic diagram which shows the structural example of the power conversion apparatus according to Embodiment 3 of this invention. It is a schematic diagram which shows the structural example of the power conversion apparatus according to Embodiment 4 of this invention.

In the following embodiments, where necessary for convenience, the description will be divided into a plurality of sections or embodiments, but unless otherwise specified, they are not unrelated to each other, one of which is the other. It is related to some or all modifications, details, supplementary explanations, etc. Further, in the following embodiments, when the number of elements (including the number, numerical value, quantity, range, etc.) is referred to, when it is specified in particular, or when it is clearly limited to a specific number in principle, etc. Except for this, the number is not limited to the specific number, and may be more than or less than the specific number.

Furthermore, in the following embodiments, the components (including element steps and the like) are not necessarily essential unless otherwise specified or clearly considered to be essential in principle. Needless to say. Similarly, in the following embodiments, when the shape, positional relationship, etc. of the constituent elements are referred to, the shape is substantially the same, except when it is clearly stated or when it is considered that it is not clearly the case in principle. Etc., etc. shall be included. This also applies to the above numerical values and ranges.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in all the drawings for explaining the embodiment, the same members are designated by the same reference numerals in principle, and the repeated description thereof will be omitted.

(Embodiment 1)
<< Outline of power converter >>
FIG. 1 is a schematic view showing a configuration example of a power conversion device according to the first embodiment of the present invention. The power conversion device 1a shown in FIG. 1 includes a power unit circuit 2a, an amplifier circuit 3, a power unit control unit 4a, and an amplifier control unit 5a. The power conversion device 1a converts the input voltage Vi from the externally provided input power supply 101 into a predetermined voltage required by the load (specifically, the motor 102), and outputs the converted voltage to the motor 102. ..

The high potential side end of the input power supply 101 is connected to one input end P1 of the power unit circuit 2a, and the low potential side end of the input power supply 101 is connected to the other input end N1 of the power unit circuit 2a. There is. The high potential side end of the power unit circuit 2a is connected to one input end P2 of the amplifier circuit 3, and the low potential side end of the power unit circuit 2a is connected to the other input end N2 of the amplifier circuit 3. There is. The end portion of the motor 102 is connected to the output ends U1, V1 and W1 of the amplifier circuit 3, respectively.

The power unit circuit 2a includes a reactor L and a switching element Q0a, and converts an input voltage Vi into an output voltage Vo which is a power supply voltage Va of the amplifier circuit 3. In detail, the power unit circuit 2a includes an input capacitor Ci, a reactor L, a switching element Q0a, a diode D, and an output capacitor Co. The switching element Q0a is, for example, an IGBT (Insulated Gate Bipolar Transistor) or the like.

The input capacitor Ci is a capacitor for smoothing the voltage input from the input power supply 101. Both ends of the input capacitor Ci are connected to the input ends P1 and N1, respectively, and the input voltage Vi is applied. The reactor L, the switching element Q0a, and the diode D constitute a boost converter. The power unit circuit 2a applies a desired output voltage Vo to the output capacitor Co by driving the gate of the switching element Q0a by PWM signal PWM from the power unit control unit 4a.

The amplifier circuit 3 includes an amplifier input capacitor Ca and a plurality of switching elements Q1 to Q6, and supplies electric power to the motor 102. The plurality of switching elements Q1 to Q6 are, for example, IGBTs and the like, and form a three-phase inverter circuit. The output voltage Vo of the power unit circuit 2a is applied to the amplifier input capacitor Ca. The amplifier circuit 3 operates using the output voltage Vo applied to the amplifier input capacitor Ca as the power supply voltage Va. The amplifier circuit 3 applies a desired voltage to the motor 102 by driving the gates of the switching elements Q1 to Q6 by the six PWM signals PWMa from the amplifier control unit 5a. As a result, the rotation speed, torque, and the like of the motor 102 are controlled.

The power unit control unit 4a is mounted on a component such as a microcontroller (abbreviated as a microcomputer), and controls switching of the switching element Q0a of the power unit circuit 2a by PWM signal PWM. In detail, the power unit control unit 4a includes a voltage control unit 7, a current feedforward calculation unit (current command value calculation unit) 8a, and a current control unit 9. The value of the output voltage Vo of the power unit circuit 2a and the reference voltage value (voltage command value) Vref, which is a predetermined target value of the output voltage Vo, are input to the voltage control unit 7.

The reference voltage value Vref is input from an external device. The external device may be provided, for example, inside the device having the power conversion device 1a, or may be provided outside the device having the power conversion device 1a. The voltage control unit 7 uses, for example, PI (proportional / integral) control or the like to bring the voltage error closer to zero based on the voltage error between the input reference voltage value Vref and the output voltage Vo value, and the reference current correction value ΔIref. Is calculated.

The current feed forward calculation unit (current command value calculation unit) 8a generally includes the angular speed ω and torque value T of the motor 102 and the input voltage Vi or output voltage Vo value of the power unit circuit 2a as parameters. The reference current value (current command value) Iref for the power unit circuit 2a is calculated by the equation. Although the details will be described later, the current feed forward calculation unit 8a calculates the reference current value Iref by, for example, the equation (1). “X” is a predetermined correction ratio coefficient (X: 0 ≦ X ≦ 1).
Iref (t) = {(ω (t) × T (t)) / Vi (t)} × X + ΔIref (t)… (1)

Based on the current error between the reference current value (current command value) Iref from the current feedforward calculation unit 8a and the reactor current value IL of the reactor L, the current control unit 9 uses, for example, PI control to obtain the current error. Calculate the control value (specifically, the duty value) that approaches zero. The reactor current value IL is detected, for example, by providing a current sensor in the power unit circuit 2a. Then, the current control unit 9 generates a PWM signal PWM based on the calculated control value, and switches and controls the switching element Q0a of the power unit circuit 2a by the PWM signal PWM.

The amplifier control unit 5a is mounted on, for example, a component such as a microcomputer different from the power unit control unit 4a, and the switching elements Q1 to Q6 of the amplifier circuit 3 are switched and controlled by the PWM signal PWMa. In detail, the amplifier control unit 5a includes a state quantity calculation unit 6, a speed control unit 10, a torque control unit 11, and a drive current control unit 12. The state quantity calculation unit 6 inputs the value of the power supply voltage Va of the amplifier circuit 3, the phase current values Iu, Iv, Iw of the motor 102, and the position information PS of the motor 102, and the angular speed ω and the torque value of the motor 102. T and the drive current value Im are calculated. The phase current values Iu, Iv, and Iw are detected, for example, by providing a current sensor in the amplifier circuit 3. The position information PS is detected, for example, by providing the motor 102 with an angle sensor such as a Hall element, a resolver, or a rotary encoder.

The speed control unit 10 is based on the speed error between the angular velocity command value ωref set separately and the angular velocity ω from the state quantity calculation unit 6, for example, a torque command for making the speed error close to zero by using PI control or the like. Calculate the value Torf. The torque control unit 11 is based on the torque error between the torque command value Tref and the torque value T from the state quantity calculation unit 6, and the drive current command value Ireffm for reducing the torque error to zero by using, for example, PI control or the like. Is calculated.

The drive current control unit 12 is based on the current error between the drive current command value Ireffm and the drive current value Im from the state quantity calculation unit 6, and is a control value for reducing the current error to zero by using, for example, PI control or the like. Calculate (duty value). Then, the drive current control unit 12 generates a PWM signal PWMa based on the calculated control value, and the switching elements Q1 to Q6 of the amplifier circuit 3 are switched and controlled by the PWM signal PWMa.

Here, as a specific example, the amplifier control unit 5a controls the motor 102 by using a known vector control. The state quantity calculation unit 6 converts the phase current values Iu, Iv, and Iw of the uvw axis into the dq axis to obtain the d-axis current value (Id) and the q-axis current value (Iq), which are the drive current values Im. calculate. Further, the state quantity calculation unit 6 calculates the angular velocity ω by the differential calculation of the position information PS, and for example, the torque value T is calculated by the equation (2). In equation (2), "Pn" is the pole logarithm, "Ψa" is the effective value of the armature interlinkage magnetic flux by the permanent magnet, and "Ld" and "Lq" are the d-axis and q-axis inductances, respectively. The value. These values are fixedly determined in advance.
T = Pn × {Ψa × Iq + (Ld-Lq) × Id × Iq}… (2)

<< Detailed operation of the main part of the power converter >>
FIG. 2 is a waveform diagram showing an operation example of a main part in the power conversion device of FIG. As a specific example, the motor 102 in FIG. 1 is a servomotor or the like that drives a press machine. In this case, the input voltage Vi of the power unit circuit 2a is 200 to 300 V or the like, and the output voltage Vo is 300 to 400 V or the like. FIG. 2 shows the angular velocity ω and torque value T of the motor 102 at the time of starting the motor 102 (for example, the period during which the press machine is moved toward the object), the output current Io and the output voltage Vo of the power unit circuit 2a. A waveform example of the reference current value (current command value) Iref of the power unit control unit 4a is shown.

As the motor 102 accelerates from time t1 to time t2, the angular velocity ω gradually increases. The motor 102 outputs the torque (T) required to obtain such an angular velocity ω. The electric power required for the rotation of the motor 102 (that is, the motor output) is represented by "ω × T". In the period from time t1 to time t2, the angular velocity ω increases with a constant torque (T), so that the motor output fluctuates (that is, the load fluctuates). The power (Po0) that the power unit circuit 2a should originally output according to this load fluctuation is expressed by the equation (3), and the output current (Io0) that the power unit circuit 2a should originally output is expressed by the equation (4). Will be done.
Po0 (t) = ω (t) × T (t)… (3)
Io0 (t) = (ω (t) × T (t)) / Vo (t)… (4)

Further, in the boost converter as shown in FIG. 1, the relationship between the reactor current value IL and the output current Io (Io0) is expressed by the equation (5) when the input voltage Vi and the output voltage Vo do not fluctuate. Therefore, the relationship of the equation (6) is derived from the equation (4) and the equation (5).
Vo (t) x Io0 (t) = Vi (t) x IL (t) ... (5)
IL (t) = (ω (t) × T (t)) / Vi (t)… (6)

The calculation formula of the current feed forward calculation unit 8a shown in the formula (1) is a correction ratio coefficient “X” (X: 0 ≦ X ≦) in the reactor current (IL) (in other words, the feed forward component) based on the formula (6). It is obtained by multiplying 1) and adding the reference current correction value ΔIref (in other words, the feedback component) from the voltage control unit 7. That is, the arithmetic expression of the equation (1) is a feed forward of the reactor current value IL required to obtain a predetermined motor output.

By providing such a current feed forward calculation unit (current command value calculation unit) 8a, the reference current value Iref indicates a current substantially equal to the output current (Io0) that should be originally output, as shown in FIG. The waveform becomes like that. Accordingly, the actual output current Io also becomes a current substantially equal to the output current (Io0) that should be originally output. As a result, the voltage drop of the output voltage Vo can be suppressed. In other words, by providing the current feed forward calculation unit 8a, it becomes possible to respond to load fluctuations (fluctuations in motor output) at high speed.

The correction ratio coefficient “X” in the equation (1) is set to, for example, 0.5. The correction ratio coefficient “X” may ideally be 1.0. However, in this case, in practice, the reference current value Iref may become excessive due to various error factors, which may lead to overshoot of the output voltage Vo. Then, the stability of the feedback control, the withstand voltage of the element, and the like may be adversely affected. The correction ratio coefficient “X” is a coefficient for preventing the occurrence of such an excessive reference current value Iref. Further, in the equation (1), the value of the input voltage Vi is used, but for example, when the boost ratio is not large, the equation (7) using the value of the output voltage Vo may be applied approximately. ..
Iref (t) = {(ω (t) × T (t)) / Vo (t)} × X + ΔIref (t)… (7)

Here, FIG. 2 shows, as a first comparative example, a reference current value Iref', an output current Io', and an output voltage Vo'when the current feed forward calculation unit 8a is not provided. In this case, the reference current value Iref'is a value such that the feedforward component is deleted from the equation (1), and only the reference current correction value ΔIref (feedback component) is input to the current control unit 9.

In the first comparative example, first, the actual output current Io'is insufficient with respect to the output current (Io0) that should be output, so that a voltage drop of the output voltage Vo'occurs. Based on the voltage error associated with this voltage drop, the voltage control unit 7 generates a reference current value Iref'(reference current correction value ΔIref) for suppressing the voltage drop by using PI control or the like. Here, if the control band of the voltage control unit 7 can be designed to be sufficiently high, the reference current value Iref'can be made to follow the output current (Io0) that should be originally output at high speed. However, in reality, the control band can only be increased to some extent from the viewpoint of preventing oscillation of feedback control.

As a result, a discrepancy occurs between the reference current value Iref'(and by extension, the actual output current Io') and the output current (Io0) that should be output, and a relatively large voltage drop occurs in the output voltage Vo'. .. On the other hand, if the current feed forward calculation unit 8a is provided, the value of the output current (Io0) that should be originally output can be calculated at high speed by the feed forward component of the equation (1), and the result is reflected in the current control unit 9 at an early stage. Can be made to. In other words, instead of increasing the output current Io as a result of the actual voltage drop, the output current Io can be increased before the actual voltage drop occurs. As a result, as a substantial effect, even when the control band of the voltage control unit 7 is low, it becomes possible to respond to load fluctuations at high speed.

Further, as a second comparative example, it is conceivable to use the method of Patent Document 1. The method of Patent Document 1 is a method of generating a command value of a step-up power source based on a predetermined map for a purpose different from that of the method of the first embodiment. Here, a method of feeding forward the calculation result of “ω × T” to the reference voltage value (voltage command value) Vref by using the method can be considered. However, in this case, the response speed may not be sufficiently increased.

Specifically, when the voltage command value is changed, the corresponding current command value (ΔIref) is calculated via the delay associated with the PI control of the voltage control unit 7, and then the delay associated with the PI control of the current control unit 9 is calculated. After that, the actual current control will be performed. Therefore, in the method of the second comparative example, the response speed is lower than that of the method of the first embodiment in which the feed forward is performed to the reference current value (current command value) Iref.

Further, as shown in FIG. 1, in a cascade control loop in which the voltage feedback loop associated with the voltage control unit 7 is a major loop and the current Ford back loop associated with the current control unit 9 is a minor loop, the major loop is generally used. The control band is designed to be about 1/10 of the minor loop. Therefore, in the method of the second comparative example in which the feedback is given to the major loop, the response speed is significantly reduced as compared with the method of the first embodiment in which the feedback is given to the minor loop.

<< Main effect of Embodiment 1 >>
As described above, by using the power conversion device of the first embodiment, it is possible to typically respond to load fluctuations at high speed. As a result, since the voltage drop of the output voltage Vo can be suppressed, the capacitance value of the output capacitor Co can be reduced, and the device can be downsized and the cost can be reduced. That is, in order to suppress the voltage drop as shown in the output voltage Vo'in FIG. 2, a method of increasing the capacitance value of the output capacitor Co can be considered, but the necessity is eliminated.

Further, as a result of suppressing the voltage drop of the output voltage Vo, it becomes possible to stably output a high torque to the motor 102. In the equation (1), the torque value T from the state quantity calculation unit 6 is used, but in some cases, the torque command value Tref from the speed control unit 10 can also be used. However, normally, the control band of the speed control unit 10 is low, and the desired torque command value Tref is calculated after a certain delay. Therefore, from the viewpoint of the response speed, the torque value T from the state quantity calculation unit 6 is used. Is preferable.

(Embodiment 2)
<< Outline of power converter (application example) >>
FIG. 3 is a schematic view showing a configuration example of the power conversion device according to the second embodiment of the present invention. The power conversion device 1b shown in FIG. 3 has slightly different configurations of the power unit control unit 4b and the amplifier control unit 5b as compared with the configuration example of FIG. The amplifier control unit 5b further has a calculation unit 21 as compared with the amplifier control unit 5a shown in FIG. The calculation unit 21 calculates the integrated value of the angular velocity ω and the torque value T from the state quantity calculation unit 6. Then, the amplifier control unit 5b transmits the integrated value “ω × T” to the power unit control unit 4b via a predetermined communication path 22 provided between the amplifier control unit 5b and the power unit control unit 4b. The communication path 22 is, for example, a serial line or the like.

On the other hand, the power unit control unit 4b has different input information to the current feed forward calculation unit 8b as compared with the configuration example of FIG. The current feed forward calculation unit (current command value calculation unit) 8b does not need to calculate the integrated value of the angular velocity ω and the torque value T as in the case of FIG. 1, and the integrated value already calculated by the calculation unit 21 “ The operation of the equation (1) is performed using "ω × T". The calculation unit 21 further calculates a value obtained by dividing the integrated value “ω × T” by the value of the power supply voltage Va (= output voltage Vo) of the amplifier circuit 3, and the amplifier control unit 5b calculates the calculated value. May be transmitted to the power unit control unit 4b. In this case, the current feed forward calculation unit 8b may perform the calculation of the equation (7), for example.

For example, the amplifier control unit 5b is often composed of a microcomputer or the like having a higher speed than the power unit control unit 4b. In this case, the amplifier control unit 5b can reduce the processing load of the current feed forward calculation unit 8b by calculating the integrated value “ω × T” (or “(ω × T) / Va”). As a result, the arithmetic processing speed of the equation (1) (or the equation (7)) can be increased, and the response speed can be increased. Further, the information on the communication path 22 can be increased as compared with the case of FIG. Since the amount can be reduced, it is possible to improve the communication speed, reduce the communication load, reduce the area around the communication circuit, and reduce the cost.

<< Main effect of Embodiment 2 >>
As described above, by using the power conversion device of the second embodiment, the same effects as the various effects described in the first embodiment can be obtained. Further, the calculation processing speed of the current feed forward calculation unit 8b can be increased as compared with the case of the first embodiment. In this example, a direct communication path is provided between the amplifier control unit 5b and the power unit control unit 4b, but in some cases, an indirect communication path may be provided. For example, the amplifier control unit 5b may transmit the integrated value to a management server such as a factory, and the power unit control unit 4b may acquire the integrated value from the management server. At this time, the management server may determine the presence or absence of an abnormality or the like based on the received integrated value.

(Embodiment 3)
<< Outline of power conversion device (modification example) >>
FIG. 4 is a schematic diagram showing a configuration example of the power conversion device according to the third embodiment of the present invention. The power conversion device 1c shown in FIG. 4 has a different configuration of the power unit circuit 2b and the power unit control unit 4c as compared with the configuration example of FIG. In the power unit circuit 2b, unlike the configuration example of FIG. 3 (and FIG. 1), the switching element Q0b, the diode D, and the reactor L form a step-down converter. The power unit control unit 4c has a current feed forward calculation unit (current command value calculation unit) 8c different from that in FIG. The value of the output voltage Vo is input to the current feed forward calculation unit 8c instead of the input voltage Vi.

Here, in the case of a boost converter as shown in FIG. 3 (and FIG. 1), the output current Io and the reactor current (IL) do not match. In this case, in order to obtain the reactor current value IL (formula (6)) from the equation (4), the relationship of the equation (5) is required. On the other hand, in the case of the step-down converter as shown in FIG. 4, the output current Io and the reactor current (IL) match. Therefore, as in the equation (8), the reactor current value IL can be obtained by using the equation (4) as it is. Along with this, the current feed forward calculation unit 8c uses the reference current value (current command) using the equation (7) using the value of the output voltage Vo as the parameter instead of the equation (1) having the value of the input voltage Vi as the parameter. Value) Calculate Iref.
IL (t) = (ω (t) × T (t)) / Vo (t)… (8)

<< Main effect of Embodiment 3 >>
As described above, by using the power conversion device of the third embodiment, the same effects as the various effects described in the first and second embodiments can be obtained even when the buck converter is used.

(Embodiment 4)
<< Outline of power converter (application example) >>
FIG. 5 is a schematic view showing a configuration example of the power conversion device according to the fourth embodiment of the present invention. The power conversion device 1d shown in FIG. 5 has N (N is an integer of 2 or more) of each of the amplifier circuit and the amplifier control unit as shown in FIG. 1 or FIG. In this example, “N = 2”, and the power conversion device 1d has a master amplifier circuit 3m, a master amplifier control unit 5m, and a slave amplifier circuit 3s and a slave amplifier control unit 5s. The power unit circuit 2 and the power unit control unit 4 are provided in common for N amplifier circuits 3m and 3s (two in this example).

The motor 103 is, in this example, a multi-axis motor having a master axis and a slave axis. The power conversion device 1d synchronously controls the rotation of the master shaft and the rotation of the slave shaft. That is, the master amplifier circuit 3m and the amplifier control unit 5m control the rotation of the master shaft, and the slave amplifier circuit 3s and the amplifier control unit 5s control the rotation of the slave shaft so as to be synchronized with the rotation of the master shaft. .. The amplifier control unit 5m of the master is provided with, for example, a configuration example as shown in FIG. 3, and the torque command value Tref calculated by the speed control unit 10 and the angular velocity ω calculated by the state quantity calculation unit 6 are combined with the position information PS. It is transmitted to the amplifier control unit 5s of the slave. The slave amplifier control unit 5s has, for example, a configuration in which the speed control unit 10 and the calculation unit 21 are deleted from the configuration example of FIG. 3, and the control operation is performed using various information transmitted from the master amplifier control unit 5m. I do.

Here, any one of the N amplifier control units 5m and 5s (here, the master amplifier control unit 5m) multiplies the integrated value “ω × T” obtained by the calculation unit 21 by “N”. The value is transmitted to the power unit control unit 4 via the communication path 22. The current feed forward calculation unit in the power unit control unit 4 performs the calculation by replacing “ω × T” in the equation (1) with “ω × T × N”, for example.

In this way, when the master axis and the slave axis are controlled synchronously, the master amplifier rather than each of the two amplifier control units 5m and 5s transmitting "ω × T" information to the power unit control unit 4. It is more efficient for the control unit 5m to transmit the summarized information "ω × T × N" to the power unit control unit 4. Specifically, the calculation processing speed in the current feed forward calculation unit is improved, the communication speed between the power unit control unit 4 and the amplifier control unit is improved, the communication load is reduced, and the area around the communication circuit is reduced. Cost reduction can be achieved.

<< Main effect of Embodiment 4 >>
As described above, by using the power conversion device of the fourth embodiment, the same effects as those described in the first and second embodiments can be obtained even when the multi-axis motor is the control target.

Although the invention made by the present inventor has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment and can be variously modified without departing from the gist thereof. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. .. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

For example, the switching element and the diode constituting the semiconductor element may be composed of an element such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Further, the power unit circuit is not limited to the boost converter and the step-down converter, and may be, for example, a buck-boost converter, an isolated DCDC converter, or the like. That is, it may be at least a power unit circuit controlled by the current control unit.

Further, here, the configuration in which the switching element of the power unit circuit is controlled by the PWM signal is taken as an example, but the configuration is controlled by the PFM (Pulse Frequency Modulation) signal, or the PWM signal and the PFM signal are appropriately switched and controlled. Is also applicable. Further, the power conversion device may be configured independently, or may be incorporated into various devices such as a control IC together with other components.

1a to 1d Power converter 2,2a, 2b Power unit circuit 3,3m, 3s Amplifier circuit 4,4a to 4c Power unit control unit 5a, 5b, 5m, 5s Amplifier control unit 7 Voltage control unit 8a, 8b Current feed forward calculation unit (Current command value calculation unit)
9 Current control unit 22 Communication path 102,103 Motor IL Reactor current value Iref reference current value (current command value)
L Reactor Q0a, Q0b, Q1 to Q6 Switching element Va Power supply voltage Vi Input voltage Vo Output voltage Vref Reference voltage value ΔIref Reference current correction value

Claims (6)

An amplifier circuit that includes a plurality of first switching elements to supply power to the motor,
An amplifier control unit that switches and controls the plurality of first switching elements,
A power unit circuit that includes a reactor and a second switching element and converts an input voltage into an output voltage that is the power supply voltage of the amplifier circuit.
A power unit control unit that switches and controls the second switching element,
It is a power conversion device that has
The power unit control unit calculates a current command value for the power unit circuit by an arithmetic expression including the angular speed and torque value of the motor and the input voltage or output voltage value of the power unit circuit as parameters. Has a part,
The power converter is
The first component on which the amplifier control unit is mounted and
The second component on which the power unit control unit is mounted and
A communication path provided between the first component and the second component,
Have,
The amplifier control unit calculates an integrated value of the angular velocity and the torque value of the motor , divides the integrated value by the value of the power supply voltage of the amplifier circuit, and transmits the value obtained by dividing the integrated value to the power unit control unit via the communication path. do,
Power converter. An amplifier circuit that includes a plurality of first switching elements to supply power to the motor,
An amplifier control unit that switches and controls the plurality of first switching elements,
A power unit circuit that includes a reactor and a second switching element and converts an input voltage into an output voltage that is the power supply voltage of the amplifier circuit.
A power unit control unit that switches and controls the second switching element,
It is a power conversion device that has
The power unit control unit calculates a current command value for the power unit circuit by an arithmetic expression including the angular speed and torque value of the motor and the input voltage or output voltage value of the power unit circuit as parameters. Has a part,
The power converter is
The first component on which the amplifier control unit is mounted and
The second component on which the power unit control unit is mounted and
A communication path provided between the first component and the second component,
Have,
Each of the amplifier circuit and the amplifier control unit has N (N is an integer of 2 or more).
The power unit circuit is provided in common for the N amplifier circuits.
Any one of the N amplifier control units calculates the integrated value of the angular velocity and the torque value of the motor, and transmits the value obtained by multiplying the integrated value by N to the power unit control unit via the communication path. do,
Power converter. In the power conversion device according to claim 1,
The power unit control unit
A voltage control unit that calculates a reference current correction value that brings the voltage error closer to zero based on a voltage error between a predetermined reference voltage value and the output voltage value of the power unit circuit.
Based on the current error between the current command value from the current command value calculation unit and the current value of the reactor, a control value that brings the current error close to zero is calculated, and the second switching element is based on the control value. And the current control unit that switches and controls
Have,
The calculation formula of the current command value calculation unit further includes the reference current correction value as a parameter.
Power converter. In the power conversion device according to claim 3 ,
The current command value calculation unit sets the current command value to "Iref", the angular velocity and torque value of the motor to "ω" and "T", respectively, and the value of the input voltage or the output voltage of the power unit circuit to "V". ”, The reference current correction value is“ ΔIref ”, and the predetermined coefficient is“ X ”(0 ≦ X ≦ 1), and“ Iref = {(ω × T) / V} × X + ΔIref ”is calculated.
Power converter. In the power conversion device according to claim 2 ,
The power unit circuit is a boost converter.
The calculation formula of the current command value calculation unit includes the value of the input voltage of the power unit circuit as a parameter.
Power converter. In the power conversion device according to claim 2 ,
The power unit circuit is a step-down converter and is
The calculation formula of the current command value calculation unit includes the value of the output voltage of the power unit circuit as a parameter.
Power converter.

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