JP7099186B2 - Rotating electric machine control device - Google Patents

Description

The present invention relates to a control device for a rotary electric machine that drives a rotary electric machine to rotate.

Patent Document 1 discloses a system including a rotary electric machine, in which the control amount of the rotary electric machine is feedback-controlled to a target value. In Patent Document 1, a controlled object is modeled using mechanical characteristics such as inertia and kinematic viscosity coefficient, and each control coefficient used for feedback control is defined based on each element of the modeled controlled object. ..

Japanese Unexamined Patent Publication No. 2006-195566

By the way, while standardizing the rotary electric machine, the shape and weight of the rotating body attached to the rotary electric machine may be different depending on the specifications of the system. In this case, since the mechanical characteristics of the controlled object differ due to the difference in the rotating body, there is a concern that the responsiveness showing the characteristics when the rotation speed changes may vary between the systems provided with the different rotating bodies. In order to suppress the variation in responsiveness, it is necessary to model the control target according to each rotating body and adapt the value of each control coefficient from each element of the modeled control target. Therefore, it is necessary to match the control coefficient for each system having a different rotating body, and there is a concern that the productivity of the system will not be improved.

INDUSTRIAL APPLICABILITY The present invention has been made in view of the above problems, and provides a control device for a rotating electric machine capable of suppressing a variation in the responsiveness of a rotating speed due to a difference in a rotating body and improving the productivity of a system. With the goal.

In order to solve the above problems, in the first invention, a rotary electric machine in which a rotating body is attached to a rotating shaft, and a power conversion unit that converts electric power from a power source and supplies the converted electric power to the rotary electric machine. It relates to the control device of the rotary electric machine applied to the system provided. The control device includes a speed acquisition unit that acquires the rotation speed of the rotary electric machine, a speed portion calculation unit that calculates a feedback operation amount for controlling the acquired rotation speed to a target value, and the acquired rotation speed. Based on the above, the load amount calculation unit that calculates the feed forward operation amount, which is a value corresponding to the load torque of the rotary electric machine and becomes larger as the rotation speed is larger, as the load operation amount, and the feedback operation amount. It includes an operation unit that operates the power conversion unit based on a command operation amount that is a value obtained by adding the load operation amount.

The torque of the rotary electric machine includes an acceleration / deceleration torque that contributes to an increase in the rotation speed of the rotating body and a load torque that does not contribute to the increase in the rotation speed of the rotating body. Therefore, since the acceleration / deceleration torque differs depending on the ratio of the load torque to the torque of the rotary electric machine, the load torque causes a variation in responsiveness to the rotation speed of the rotary electric machine. Further, since the mechanical characteristics of the controlled object differ depending on the shape and weight of the rotating body, it is conceivable that the difference in the rotating body causes the load torque to differ. Here, the present inventor pays attention to the relationship that the load torque increases as the rotation speed of the rotating body increases, and feed forward for compensating the load torque based on the rotation speed of the rotating electric machine that rotates the rotating body. We obtained the knowledge that the operation amount is calculated.

In this regard, in the above configuration, the feed forward operation amount, which is a value corresponding to the load torque of the rotary electric machine and increases as the rotation speed of the rotary electric machine increases, is calculated as the load operation amount based on the rotation speed of the rotary electric machine. To. Further, the power conversion unit is operated based on the command operation amount which is the value obtained by adding the load operation amount to the feedback operation amount for controlling the rotation speed of the rotating body to the target value. As a result, the load operation amount that compensates for the load torque is calculated each time from the rotation speed of the rotary electric machine, and the power conversion unit is operated by the command operation amount including this load operation amount. Therefore, it is possible to suppress variations in the responsiveness of the rotation speed between the systems even when different rotating bodies are provided for each system while standardizing the rotating electric machine. As a result, it is not necessary to match the control coefficient according to the difference in the rotating body, so that the productivity of the system can be improved.

In the second invention, the rotating body is a fan, and the load calculation unit calculates the load operation amount by adding a positive value, which is a load coefficient, to the squared value of the acquired rotation speed. Calculated as.

When the rotating body is a fan, it is conceivable that the load torque increases non-linearly as the rotation speed increases. In this respect, in the above configuration, the value obtained by integrating the load coefficient, which is a positive value, into the squared value of the rotation speed of the rotary electric machine is calculated as the load operation amount. As a result, it is possible to suitably suppress the variation in the responsiveness of the rotation speed due to the difference in the fan between the systems.

In the third invention, the feed forward operation amount, which is a value corresponding to the power loss of the rotary electric machine and becomes larger as the rotation speed is larger, is calculated as the loss operation amount based on the acquired rotation speed. The operation unit operates the power conversion unit based on a value obtained by subtracting the loss operation amount from the command operation amount.

In the configuration in which the load torque is compensated by the command operation amount to which the load operation amount is added, the amount of the disturbance torque offset by the load torque in the rotary electric machine is reduced, and the change in the rotation speed due to the disturbance torque is the load torque. It is feared that it will be larger than if it is not compensated. In particular, when a positive disturbance torque is applied to the rotary electric machine, there is a concern that the stability of the system may deteriorate due to a large change in the rotation speed. Therefore, the feed forward operation amount, which is a value corresponding to the power loss amount of the rotary electric machine and becomes larger as the rotation speed is higher, is calculated as the loss operation amount. Then, the power conversion unit is operated based on the value obtained by subtracting the loss operation amount from the command operation amount. Therefore, the electric power supplied from the power conversion unit to the rotary electric machine is subtracted according to the loss operation amount, so that the increase in the rotation speed due to the disturbance torque is suppressed. As a result, the deterioration of the stability of the system due to the disturbance torque can be suppressed, and the variation in the responsiveness between the systems can be suitably suppressed.

In the fourth invention, the loss amount calculation unit calculates the loss operation amount by integrating the loss amount coefficient, which becomes a large value according to the power loss amount of the rotary electric machine, into the rotation speed.

In the above configuration, the amount of power loss of the rotary electric machine can be calculated linearly according to the rotation speed, so that the calculation load of the control device can be suppressed.

In the fifth invention, the speed calculation unit calculates the feedback operation amount for feedback-controlling the acquired rotation speed to the target value, and the integrated gain in the feedback control is the loss amount coefficient. The larger the value, the larger the value.

In the configuration in which the load torque is compensated by subtracting the loss operation amount from the command operation amount, the command operation amount is reduced by the loss operation amount. Therefore, when performing feedback control that controls the rotation speed to the target value, the steady deviation between the rotation speed and the target value becomes more difficult to converge as the command operation amount decreases as the loss operation amount increases. I am concerned. In this respect, in the above configuration, the integrated gain in the feedback control is set to a value larger as the loss amount coefficient is larger. As a result, it is possible to appropriately suppress that the steady-state deviation becomes difficult to converge due to the suppression of the disturbance torque. As a result, variations in responsiveness between systems can be suitably suppressed.

The block diagram of the cooling system which concerns on 1st Embodiment. A block diagram that models each function of the cooling system. A block diagram that models each function of the cooling system. The block diagram of the cooling system which concerns on 2nd Embodiment. The figure explaining the transition of the rotation speed with the disturbance torque. The block diagram of the cooling system which concerns on 3rd Embodiment.

<First Embodiment>
Hereinafter, embodiments of the cooling system according to the present invention will be described with reference to the drawings. The cooling system of the present embodiment is installed in the engine room of the vehicle and cools the engine of the vehicle.

The cooling system 100 shown in FIG. 1 includes a radiator 11 that dissipates heat from the cooling water flowing through the engine, a cooling fan 12 that air-cools the cooling water flowing through the radiator 11, and a motor 20 that rotates the cooling fan 12. There is. The radiator 11 is connected to the engine via a cooling water passage (not shown) composed of an outward flow path and a return flow path. The cooling fan 12 is attached to the rotating shaft 20a of the motor 20, and is rotationally driven by the motor 20 when the vehicle is stopped or traveling at a low speed. In this embodiment, the cooling fan 12 corresponds to a rotating body.

The motor 20 is an AC drive type rotary electric machine provided with U, V, and W phase coils 21, 22, and 23.

The cooling system 100 includes an inverter 30 that converts electric power from the battery 110 as a power source and supplies the converted electric power to the motor 20, a rotation angle detecting unit 14 that detects the electric angle θ of the motor 20, and an inverter 30. It includes a control device 40 for controlling.

The inverter 30 is connected to the positive electrode terminal and the negative electrode terminal of the battery 110, converts the DC power supplied from the battery 110 into three-phase AC power of U, V, and W, and supplies the DC power to the motor 20. In the present embodiment, the inverter 30 has a series connection body of a set of switching elements for each phase of U, V, and W, and each series connection body is connected in parallel. The connection points of the switching elements of each phase are connected to the U, V, and W phase coils 21 to 23 of the motor 20 via the power lines L1, L2, and L3. Each switching element is turned on and off by an operation signal output from the control device 40 to supply power to the phase coils 21 to 23 via the power lines L1 to L3. For example, the switching element is composed of MOSFETs. In this embodiment, the inverter 30 corresponds to a power conversion unit.

The power lines L1 to L3 connecting the inverter 30 and the phase coils 21 to 23 are provided with a current detection unit 13. The current detection unit 13 includes a U-phase detection unit 13a that detects the current flowing through the U-phase coil 21 as a U-phase current Iu, and a V-phase detection unit 13b that detects the current flowing through the V-phase coil 22 as a V-phase current Iv. It is provided with a W-phase detection unit 13c that detects the current flowing through the W-phase coil 23 as the W-phase current Iw. The U-phase detection unit 13a is provided on the power line L1 connecting the inverter 30 and the U-phase coil 21, and the V-phase detection unit 13b is provided on the power line L2 connecting the inverter 30 and the V-phase coil 22. The W-phase detection unit 13c is provided on the power line L3 that connects the inverter 30 and the W-phase coil 23. In the present embodiment, each phase detection unit 13a to 13c constituting the current detection unit 13 is composed of, for example, a shunt resistor. The phase detection units 13a to 13c may be configured by Hall ICs.

The rotation angle detection unit 14 detects the electric angle θ of the motor 20. Therefore, it is possible to calculate the rotation speed ωr of the motor 20 by differentiating this electric angle θ. The rotation angle detection unit 14 is composed of, for example, a resolver.

The control device 40 is mainly composed of a well-known microcomputer including a CPU, a ROM, a RAM, and an I / OIF. Each function provided by the control device 40 can be provided, for example, by software recorded in a substantive memory device and a computer, hardware, or a combination thereof that executes the software.

The control device 40 calculates the rotation speed ωr of the motor 20 from the electric angle θ of the motor 20, and performs speed feedback control for controlling the calculated rotation speed ωr to the speed command value ω *. The control device 40 includes a gradual changer 41, a current command value calculation unit 42, a current control unit 43, a voltage command value calculation unit 44, and a three-phase two-phase coordinate conversion unit 45. In this embodiment, the control device 40 corresponds to the speed acquisition unit.

A speed command value ω * indicating a target value of the rotation speed ωr of the motor 20 is input to the gradual changer 41. The gradual changer 41 outputs a value obtained by gradually changing the speed command value ω * in response to a change in the speed command value ω *.

The current command value calculation unit 42 acquires the rotation speed ωr and calculates the feedback operation amount for controlling the rotation speed ωr to the speed command value ω * after the gradual change. In the present embodiment, the current command value calculation unit 42 calculates the q-axis current command value Iq *, which is a value on the dq coordinates, as the feedback operation amount. Here, among the axes that define the dq coordinates, the q-axis is the axis of the active current component, that is, the torque current component that is the current that contributes to the torque of the motor 20. The d-axis is an axis of an ineffective current component, that is, an exciting current component which is a current contributing to a rotating magnetic field accompanying the rotation of the motor 20.

The three-phase two-phase coordinate conversion unit 45 converts each phase current Iu, Iv, and Iw into a q-axis current Iqr, which is a value on the dq coordinate, based on the electric angle θ of the motor 20.

The current control unit 43 calculates a value obtained by subtracting the q-axis current Iqr from the q-axis current command value Iq * as the current deviation ΔIq.

The voltage command value calculation unit 44 calculates an operation signal GS for operating each phase semiconductor switch of the U, V, W of the inverter 30 based on the current deviation ΔIq calculated by the current control unit 43. In the present embodiment, the voltage command value calculation unit 44 first applies the voltage applied to each of the U, V, and W phase coils 21 to 23 from the current deviation ΔIq based on the current deviation ΔIq and the electric angle θ of the motor 20. The U-phase voltage, V-phase voltage, and W-phase voltage are calculated. Then, the operation signal GSu for operating the U-phase switch of the inverter 30 is calculated based on the U-phase voltage, the operation signal GSv for operating the V-phase switch is calculated based on the V-phase voltage, and the W-phase voltage is calculated. The operation signal GSw for operating the W phase switch is calculated based on the above. In the present embodiment, the current control unit 43 and the voltage command value calculation unit 44 correspond to the operation unit.

FIG. 2 is a block diagram modeling each function of the cooling system 100 in the comparative example. In FIG. 2, the block 400 is a model of the function of the control device 40, and the block 200 is a model of the function of the motor 20 to be controlled.

The value obtained by subtracting the rotation speed ωr from the speed command value ω * by the deviation calculation block 401 of the block 400 is the speed deviation Δω. The value obtained by controlling the speed feedback of the speed deviation Δω by the command value calculation block 402 becomes the q-axis current command value Iq *. In the present embodiment, the command value calculation block 402 performs PI control (proportional integral control) as feedback control, and the proportional gain KP integrated in the velocity deviation Δω and the integrated gain integrated in the integrated value of the velocity deviation Δω. It is composed of KI.

The motor torque T1 is obtained by multiplying the q-axis current command value Iq * by the motor torque coefficient KT by the motor torque block 201 of the block 200. The motor torque T1 indicates the total torque that the motor 20 can output according to the q-axis current command value Iq *. Here, the motor torque T1 includes an acceleration / deceleration torque T2 that contributes to an increase in the rotation speed ωr of the cooling fan 12, and a load torque T3 that does not contribute to an increase in the rotation speed ωr of the cooling fan 12. Therefore, the value obtained by subtracting the load torque T3 from the motor torque T1 by the subtraction block 202 becomes the acceleration / deceleration torque T2. The rotation speed ωr of the cooling fan 12 is the value obtained by integrating the acceleration / deceleration torque T2 with the transfer function (= 1 / (sJ + D1)) corresponding to the mechanical characteristics of the motor 20 and the cooling fan 12 by the characteristic block 203. J is the synthetic inertia [kg / m ^ 2] of the motor 20 and the cooling fan 12, and D1 is the kinematic viscosity coefficient (Nm / (rad / s)) of the motor 20.

By the way, in the cooling system 100, the shape and weight of the cooling fan 12 may be different depending on the specifications while sharing the motor 20. In this case, since the mechanical characteristics of the controlled object differ due to the difference in the cooling fan 12, there is a concern that the responsiveness of the rotation speed may vary among the cooling systems 100 provided with the different cooling fans 12. Therefore, in order to suppress the variation in the responsiveness of the rotation speed ωr among the cooling systems 100, it is conceivable to remodel the cooling system 100 according to the difference between the cooling fans 12 and match the control coefficients. .. Therefore, it is necessary to match the control coefficient of the control device 40 for each of the different cooling fans 12, and there is a concern that the productivity will not be improved. Further, even if the cooling fans 12 are of the same type, the work load of the cooling fans 12 may differ due to the difference in the rotation direction of the cooling fans 12, and the load torque T3 may also change.

Here, since the acceleration / deceleration torque T2 differs depending on the ratio of the load torque T3 to the motor torque T1, the load torque T3 causes a variation in the responsiveness to the speed command value ω * of the motor 20. Further, since the value of the load torque T3 differs depending on the shape, weight, etc. of the cooling fan 12, the difference in the load torque T3 due to the difference in the cooling fan 12 is the difference in the rotation speed ωr due to the difference in the cooling fan 12. It becomes a factor that disperses the responsiveness.

The present inventor pays attention to the relationship that the load torque T3 increases as the rotation speed of the cooling fan 12 increases, and the feed forward operation amount for compensating the load torque T3 is calculated based on the rotation speed ωr of the motor 20. It was found to calculate. Specifically, in FIG. 2, the load torque T3 can be approximated as a value obtained by integrating the load torque coefficient KF (Nm / A) into the value obtained by squaring the rotation speed ωr with the load torque block 204. Therefore, the control device 40 calculates the feed forward operation amount for compensating the load torque T3 based on the rotation speed ωr of the motor 20. Then, it was decided to operate the inverter 30 according to the value obtained by adding the calculated feedforward operation amount to the q-axis current command value Iq * which is the feedback operation amount.

Returning to FIG. 1, the current command value calculation unit 42 includes a deviation calculation unit 50, a speed component calculation unit 51, a load component calculation unit 52, and an adder 53.

The deviation calculation unit 50 calculates a value obtained by subtracting the rotation speed ωr from the speed command value ω * as the speed deviation Δω.

The speed component calculation unit 51 calculates the feedback operation amount for controlling the rotation speed ωr to the speed command value ω * as the current operation amount Iqfb. In the present embodiment, the velocity component calculation unit 51 calculates the current manipulated variable Iqfb by performing PI control using the proportional gain KP and the integrated gain KI with respect to the velocity deviation Δω.

The load amount calculation unit 52 calculates the feed forward operation amount for compensating the load torque T3 as the load operation amount ILff based on the rotation speed ωr. In the present embodiment, the load amount calculation unit 52 calculates the load operation amount ILff based on the following equation (1).
ILff = KF / KT x ωr ^ 2 ... (1)
The load torque coefficient KF is a coefficient that defines the relationship between the rotation speed ωr and the load torque T3 according to the type of load, and is a value larger than 0. Further, since the motor torque coefficient KT is a value larger than 0, the load coefficient (KF / KT), which is the value obtained by dividing the load torque coefficient KF by the motor torque coefficient KT, is a positive value. If the motor 20 has the same type, the load torque coefficient KF and the motor torque coefficient KT are set to the same value regardless of the type of the cooling fan 12.

The adder 53 outputs a value obtained by adding the load manipulated variable ILff to the current manipulated variable Iqfb as the q-axis current command value Iq *. Therefore, the value obtained by adding the load operation amount ILff, which is the compensation amount of the load torque T3, to the q-axis current command value Iq *.

In this embodiment, the following effects can be achieved.

The control device 40 calculates the operation signals GSu, GSv, GSw for operating the inverter 30 based on the q-axis current command value Iq * calculated by the current command value calculation unit 42, and the operation signals GSu, The inverter 30 supplies power to the motor 20 based on GSv and GSw. In the motor 20, the cooling fan 12 is rotationally driven by the acceleration / deceleration torque T2 corresponding to the value obtained by subtracting the load torque T3 from the motor torque T1. At this time, the load operation amount ILff that compensates for the load torque T3 is calculated each time from the rotation speed ωr of the motor 20, and the inverter 30 is operated by the q-axis current command value Iq * including this load operation amount ILff. Therefore, even if the load torque T3 differs between the cooling systems 100 due to the difference in the cooling fan 12, if the speed command value ω * is the same, the variation in the acceleration / deceleration torque T2 between the cooling systems 100 is small. It becomes. As a result, it is possible to suppress variations in the responsiveness of the rotation speed ωr among the cooling systems 100 due to the difference in the cooling fans 12.

The current command value calculation unit 42 decides to calculate the value obtained by integrating the predetermined load coefficient (= KF / KT) into the squared value of the rotation speed ωr of the motor 20 as the load operation amount ILff. Thereby, the variation in the responsiveness of the rotation speed ωr due to the difference in the cooling fan 12 can be suitably suppressed.

<Modification example of the first embodiment> As the command operation amount, the d-axis current command value Id * may be calculated in addition to the q-axis current command value Iq *. In this case, the current command value calculation unit 42 calculates the current manipulated quantities Idfb and Iqfb as the feedback manipulated quantities based on the speed deviation Δω by PI control. Then, the value obtained by adding the load manipulated variable ILff to each of the current manipulated quantities Idfb and Iqfb may be calculated as the axis current command values Id * and Iq *.

<Second Embodiment> In the second embodiment, a configuration different from that of the first embodiment will be mainly described. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will not be repeated.

3 (a) and 3 (b) are block diagrams modeling each function of the cooling system 100 in the present embodiment. FIGS. 3A and 3B show a state in which the disturbance torque T4 is added in the block 200 that models the function of the motor 20.

As shown in FIG. 3A, in the block 200 that models the function of the motor 20, the rotational speed ωr of the motor 20 becomes the disturbance torque T4 by adding the positive disturbance torque T4 to the acceleration / deceleration torque T2. It increases accordingly. For example, the positive disturbance torque T4 is the torque generated by rotating the cooling fan 12 in the forward direction by the traveling wind flowing from the front of the vehicle to the rear of the vehicle.

The control device 40 compensates for the load torque T3 by the q-axis current command value Iq * to which the load operation amount ILff is added. Therefore, in the motor 20, even when the disturbance torque T4 is smaller than the load torque T3, the disturbance torque T4 is relatively increased by compensation. As a result, there is a concern that the change in the rotational speed ωr caused by the disturbance torque T4 will be larger than in the case where the load torque T3 is not compensated. Specifically, when the load torque T3 is compensated, the disturbance torque T4 applied to the acceleration / deceleration torque T2 in the motor 20 becomes relatively large. Since the disturbance torque T4 applied to the acceleration / deceleration torque T2 becomes relatively large, the change in the rotation speed ωr caused by the disturbance torque T4 becomes large, and there is a concern that the stability of the cooling system 100 deteriorates.

Here, a power loss occurs in the motor 20, and the acceleration / deceleration torque T2 of the motor 20 is obtained by subtracting the load torque T3 and the power loss from the motor torque T1. Further, a part of the power loss can be estimated based on the rotation speed ωr indicating the state of the motor 20. FIG. 3A shows the amount of power loss associated with the bearing loss of the motor 20 and the amount of power loss that can be estimated based on the rotation speed ωr as the power loss. In the motor 20, the value (D1 × ωr) obtained by integrating the kinematic viscosity coefficient D1 by the first loss block 211 with the output value (ωr) of the characteristic block 210 is the power loss amount due to the bearing loss. Further, in the motor 20, the value (= D2 × ωr) obtained by integrating the loss amount coefficient D2 by the second loss block 212 on the rotation speed ωr of the motor 20 can be estimated based on the rotation speed ωr. Will be. The loss amount coefficient D2 is a coefficient that defines the relationship between the rotation speed ωr and the power loss amount, and becomes a larger value as the power loss amount increases. In the present embodiment, the loss amount coefficient D2 is set to a value larger than 0.

In the motor 20, the acceleration / deceleration torque T2 is obtained by subtracting the power loss amount associated with the bearing loss and the power loss amount that can be estimated based on the rotation speed ωr from the motor torque T1. Note that the load torque T3 is not shown in FIG. 3 for the sake of simplicity.

As shown in FIG. 3B, the block 410 calculates the feed forward operation amount according to the power loss amount (= D2 × ωr) that can be estimated based on the rotation speed ωr. Then, by subtracting the calculated feed forward operation amount from the q-axis current command value Iq *, it was decided to suppress the increase in the rotational speed ωr due to the addition of the disturbance torque T4. In the present embodiment, the control device 40 calculates the feed forward operation amount according to the power loss amount, which becomes a larger value as the rotation speed ωr is larger.

FIG. 4 is a block diagram of the cooling system 100 according to the present embodiment. The current command value calculation unit 42 includes a deviation calculation unit 50, a speed portion calculation unit 51, a load portion calculation unit 52, an adder 53, a loss portion calculation unit 54, and a subtractor 55. ing.

The loss amount calculation unit 54 calculates the loss operation amount IPff, which is the feed forward operation amount according to the power loss amount, based on the rotation speed ωr. Specifically, the loss amount calculation unit 54 calculates the loss manipulated variable IPff based on the rotation speed ωr by the following equation (2).
IPff = D2 / KT x ωr ... (2)
The loss amount coefficient D2 is a value larger than 0, and is determined based on the power loss amount when the cooling fan 12 rotates constantly in the present embodiment.

The subtractor 55 outputs a value obtained by subtracting the loss manipulated variable IQf from the q-axis current command value Iq * as the corrected current command value Iqa *. Therefore, the current control unit 43 calculates the value obtained by subtracting the q-axis current Iqr from the corrected current command value Iqa * as the current deviation ΔIq.

In the configuration in which the load torque T3 is compensated by subtracting the loss manipulated amount IPff from the q-axis current command value Iq *, the q-axis current command value Iq * is reduced by the loss manipulated amount IPff. Therefore, in the PI control performed by the current command value calculation unit 42, there is a concern that the steady deviation between the rotation speed ωr and the speed command value ω * will be difficult to converge. Therefore, in the present embodiment, the integrated gain KI in the speed component calculation unit 51 is set to a value larger as the loss amount coefficient D2 is larger.

FIG. 5 shows the transition of the rotation speed ωr between the present embodiment and the comparative example when the disturbance torque T4 is applied. In FIG. 5, a pulse-shaped positive disturbance torque T4 is applied to the motor 20 at time t1. In the comparative example, the integrated gain is set to a value smaller than the integrated gain of the present embodiment.

In the present embodiment and the comparative example, after the step-like disturbance torque T4 is applied at time t1, the rotation speed ωr increases, and then the rotation speed ωr decreases. In the comparative example, the rotation speed ωr gradually decreases even at the time t2 and the time t3 after the time t1, and the steady deviation between the rotation speed ωr and the speed command value ω * remains larger than the predetermined value. It has become. On the other hand, in the present embodiment, at time t2, the rotation speed ωr decreases to the speed command value ω *, so that the steady deviation becomes equal to or less than the predetermined value, and then the rotation speed ωr maintains the speed command value ω *. ing.

Therefore, in the present embodiment, as compared with the comparative example, by setting the integrated gain KI to a value larger as the loss amount coefficient D2 is larger, it is suppressed that the steady deviation of the rotation speed ωr is less likely to converge.

In the present embodiment described above, the following effects can be obtained.

The current command value calculation unit 42 determines the feed forward operation amount, which is a value corresponding to the power loss of the motor 20 based on the rotation speed ωr of the motor 20, and becomes larger as the rotation speed ωr is larger. Calculated as IPff. Then, it was decided to operate the inverter 30 based on the value obtained by subtracting the loss manipulated variable IQf from the q-axis current command value Iq *. As a result, the electric power supplied from the inverter 30 to the motor 20 is subtracted by the amount of the power loss loss, so that the increase in the rotational speed ωr due to the addition of the disturbance torque T4 is suppressed. As a result, variations in responsiveness among the cooling systems 100 can be suitably suppressed.

The loss amount calculation unit 54 calculates the loss manipulated variable IPff by integrating the loss amount coefficient D2 according to the power loss amount with the rotation speed ωr. As a result, the amount of power loss of the motor 20 can be calculated linearly according to the rotation speed ωr, so that the calculation load of the control device 40 can be suppressed.

The integrated gain KI in the PI control carried out by the speed component calculation unit 51 is set to a value larger as the loss amount coefficient D2 is larger. As a result, the integrated gain KI is set to a larger value as the amount of subtraction of the q-axis current command value Iq * by the loss manipulation amount IPff increases, so that it is possible to suppress the difficulty in converging the steady deviation of the rotation speed ωr. can. As a result, variations in responsiveness among the cooling systems 100 can be suitably suppressed.

<Modified example of the second embodiment>
When it is assumed that the disturbance torque T4 does not become larger than the predetermined value due to the specifications of the cooling system 100 or the like, the integrated gain KI in the PI control performed by the speed component calculation unit 51 is set as a value that does not depend on the magnitude of the loss amount coefficient. May be good.

<Third Embodiment> In the third embodiment, a configuration different from that of the first embodiment will be mainly described. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 6 is a block diagram of the cooling system 100 according to the third embodiment. In the present embodiment, the control device 40 does not include the current command value calculation unit 42 and the current control unit 43, and the configuration in which the voltage command value calculation unit 44 calculates the command operation amount is different from that of the first embodiment.

The voltage command value calculation unit 44 calculates the operation signals GSu, GSv, and GSw for controlling the rotation speed ωr to the speed command value ω * after the gradual change. In the present embodiment, the voltage command value calculation unit 44 includes a deviation calculation unit 61, a speed calculation unit 62, a load calculation unit 63, an adder 64, a loss calculation unit 65, and a subtractor 66. The operation signal calculation unit 67 is provided.

The deviation calculation unit 61 calculates a value obtained by subtracting the rotation speed ωr from the speed command value ω * as the speed deviation Δω. The velocity component calculation unit 62 calculates the voltage manipulated variable Vqfb by performing PI control for the velocity deviation Δω. In the present embodiment, the voltage manipulated variable Vqfb is a feedback manipulated variable for controlling the rotation speed ωr to the speed command value ω *. The load amount calculation unit 63 calculates the feed forward operation amount for compensating the load torque T3 as the load operation amount VLff based on the rotation speed ωr.

The adder 64 outputs a value obtained by adding the load manipulated variable VLff to the voltage manipulated variable Vqfb as the voltage command value Vq *. The voltage command value Vq * is the value obtained by adding the load operation amount VLff, which is the compensation amount of the load torque T3. The loss amount calculation unit 65 subtracts the loss operation amount Vpff according to the power loss amount of the cooling fan 12 from the voltage command value Vq *. Also in this embodiment, the loss amount calculation unit 65 sets the loss operation amount Vpff to a larger value as the rotation speed ωr is larger. The operation signal calculation unit 67 calculates the operation signals GSu, GSv, GSw for operating the switching element of the inverter 30 based on the voltage command value Vq * from which the loss operation amount Vpff is subtracted.

The present embodiment described above has the same effect as that of the first embodiment.

<Other embodiments>
-The rotating body attached to the motor 20 is not limited to the cooling fan 12, but any object such as a pulley or a gear whose load torque becomes larger as the rotation speed ωr of the motor 20 increases. good.

-The feedback control performed by the speed minute calculation unit 51 may use P control (proportional control) or PID control instead of PI control.

The system including the motor 20 is not limited to the cooling system 100.

10 ... rotary electric machine, 30 ... inverter, 40 ... control device, 42 ... current command value calculation unit, 51 ... speed calculation unit, 52 ... load calculation unit.

Claims (5)

A rotary electric machine (20) in which a rotary body (12) is attached to a rotary shaft (20a), and a power conversion unit (30) that converts electric power from a power source (110) and supplies the converted electric power to the rotary electric machine. A rotary electric machine control device (40) applied to the system (100) including the above.
The rotating body is a fan
A speed acquisition unit (40) for acquiring the rotation speed of the rotary electric machine, and
A speed component calculation unit (51) for calculating a feedback operation amount for controlling the acquired rotation speed to a target value, and a speed component calculation unit (51).
Based on the acquired rotation speed, a load amount calculation unit that calculates a feed forward operation amount, which is a value corresponding to the load torque of the rotary electric machine and becomes a larger value as the rotation speed is larger, as a load operation amount ( 52) and
An operation unit (43, 44) for operating the power conversion unit is provided based on a command operation amount which is a value obtained by adding the load operation amount to the feedback operation amount.
The load amount calculation unit is a control device for a rotary electric machine that calculates as the load operation amount a value obtained by integrating the acquired load coefficient, which is a positive value, into the squared value of the rotation speed. A rotary electric machine (20) in which a rotary body (12) is attached to a rotary shaft (20a), and a power conversion unit (30) that converts electric power from a power source (110) and supplies the converted electric power to the rotary electric machine. A rotary electric machine control device (40) applied to the system (100) including the above.
A speed acquisition unit (40) for acquiring the rotation speed of the rotary electric machine, and
A speed component calculation unit (51) for calculating a feedback operation amount for controlling the acquired rotation speed to a target value, and a speed component calculation unit (51).
A load amount calculation unit that calculates a feed forward operation amount, which is a value corresponding to the load torque of the rotary electric machine and becomes a larger value as the rotation speed increases, as a load operation amount based on the acquired rotation speed ( 52) and
A loss amount calculation unit that calculates a feed forward operation amount, which is a value corresponding to the power loss of the rotary electric machine and becomes a larger value as the rotation speed increases, as a loss operation amount based on the acquired rotation speed ( 54) and
A rotation including an operation unit (43, 44) for operating the power conversion unit based on a value obtained by subtracting the loss operation amount from a command operation amount which is a value obtained by adding the load operation amount to the feedback operation amount. Electric control device. A loss amount calculation unit that calculates a feed forward operation amount, which is a value corresponding to the power loss of the rotary electric machine and becomes a larger value as the rotation speed increases, as a loss operation amount based on the acquired rotation speed ( 54)
The control device for a rotary electric machine according to claim 1 , wherein the operation unit operates the power conversion unit based on a value obtained by subtracting the loss operation amount from the command operation amount. The rotary electric machine according to claim 2 or 3 , wherein the loss amount calculation unit calculates the loss operation amount by integrating the loss amount coefficient, which becomes a large value according to the power loss amount of the rotary electric machine, into the rotation speed. Control device. The speed component calculation unit calculates the feedback operation amount for feedback-controlling the acquired rotation speed to the target value.
The control device for a rotary electric machine according to claim 4 , wherein the integrated gain in the feedback control is set to a larger value as the loss amount coefficient is larger.

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