Control device, program, and control method for power converters

Abstract

To provide a controller of an electric power converter capable of increasing the temperature rise capability of the storage battery, and a program.SOLUTION: A controller 50 determines whether or not a storage battery 30 needs to be warmed up. The controller 50 is configured so as to, when determining that a temperature rise is necessary, repeat one cycle that includes a coil charging mode that gradually increases the magnitude of the current flowing through a coil 11U and a coil discharge mode, which is a mode after the coil charge mode, in which the magnitude of the current flowing through coil 11U is gradually decreased at regular intervals, and to perform a switch control an inverter 20 so that the magnitude of the current flowing through the coil 11U is greater than 0.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for a power converter. , program and control method

Background Art

[0002] Conventionally, as described in Patent Document 1, a control device for an inverter that electrically connects a coil constituting a rotating electrical machine and a battery is known. This control device causes an alternating current to flow through the battery by causing a current to flow back and forth between the coil and the battery via the inverter by switching control of the inverter. As a result, Joule heat is generated in the battery, raising the temperature of the battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the control method described in Patent Document 1, the absolute value of the current flowing through the coil periodically becomes 0, and the temperature-raising ability of the battery may be insufficient. Thus, there remains room for improvement in enhancing the temperature-raising ability of a power storage unit such as a battery.

[0005] The main object of the present invention is to provide a control device for a power converter that can enhance the temperature-raising ability of a power storage unit. 、 Program and control method

Means for Solving the Problems

[0006] The present invention includes a rechargeable power storage unit, a coil, a power converter that electrically connects the coil and the power storage unit, ​​In a control device for a power converter applied to a system comprising: A determination unit that determines whether or not it is necessary to raise the temperature of the energy storage unit, When the determination unit determines that it is necessary to raise the temperature of the energy storage unit, the power converter includes a temperature rise control unit that controls the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period that includes a coil charging mode, which gradually increases the magnitude of the current flowing through the coil, and a coil discharge mode, which is a mode after the coil charging mode and gradually decreases the magnitude of the current flowing through the coil.

[0007] In this invention, the switching control of the power converter is performed so that the magnitude of the current flowing through the coil is greater than zero in one cycle, which includes a coil charging mode and a coil discharging mode. As a result, the DC component in the current flowing through the coil can be increased, and the charge and discharge current of the energy storage unit can be increased in the coil charge and discharge mode. Consequently, the heating capacity of the energy storage unit can be enhanced.

[0008] Furthermore, in this invention, the DC component is increased to enhance the heating capacity of the energy storage unit, making it possible to increase the charging and discharging current of the energy storage unit without increasing the amount of change in the current flowing through the coil. This makes it possible to suppress the noise level generated by the coil in conjunction with the switching control by the heating control unit. [Brief explanation of the drawing]

[0009] [Figure 1] Overall configuration diagram of the control system. [Figure 2] A flowchart illustrating the procedure for temperature control. [Figure 3] A diagram showing the equivalent circuit. [Figure 4] A figure showing the frequency amplitude response characteristics. [Figure 5] A diagram illustrating an example of how to set noise tolerance levels. [Figure 6] A diagram showing the relationship between battery temperature and the maximum charge / discharge power of the battery. [Figure 7]Flowchart showing the procedure for calculating the effective value Ibatrms* of the command battery current. [Figure 8] Diagram showing the definitions of the coil average current value Imgave and the coil current change amount ΔImg. [Figure 9] Diagram showing the relationship between the coil average current value Imgave, the coil current change amount ΔImg, and the sound pressure level of noise. [Figure 10] Time chart showing the transitions of the d-axis current, coil current, and inverter current in the coil charging mode, reflux mode, and coil discharging mode. [Figure 11] Diagram showing an example of the switching pattern in the coil charging mode. [Figure 12] Diagram showing an example of the switching pattern in the reflux mode. [Figure 13] Diagram showing an example of the switching pattern in the coil discharging mode. [Figure 14] Time chart showing the transitions of the coil current and inverter current in one cycle including the coil charging mode, reflux mode, and coil discharging mode. [Figure 15] Diagram showing the relationship between the coil average current value, the coil current change amount, and the effective value of the inverter current. [Figure 16] Diagram showing the method for setting the command current average value and the command current change amount. [Figure 17] Diagram showing the relationship between the noise tolerance value, the command inverter current effective value, and the command current change amount. [Figure 18] Diagram showing the relationship between the command inverter current effective value and the command average current value. [Figure 19] Diagram showing the relationship between the noise tolerance value and the command average current value. [Figure 20] Time chart showing the transition of the coil current in one cycle including the coil charging mode, reflux mode, and coil discharging mode. [Figure 21] Diagram showing the relationship between the command current average value, the command current change amount, and the charging execution time. [Figure 22] Diagram showing the relationship between the charging execution time, the command inverter frequency, and the first reflux execution time. [Figure 23] A diagram showing the relationship between the average value of the command current and the discharge execution time. [Figure 24] A diagram showing the relationship between the average value of the command current and the discharge execution time. [Figure 25] A diagram showing the relationship between the discharge execution time, the command inverter frequency, and the second reflux execution time. [Figure 26] A diagram showing each sector and voltage vectors. [Figure 27] A diagram showing the relationship between the voltage vector and the switching pattern. [Figure 28] A diagram showing a method for generating the d-axis voltage vector when the current electrical angle belongs to sector 1. [Figure 29] A diagram showing the trajectory of the dq-axis current during the temperature rise control in the dq-axis current coordinate system. [Figure 30] A diagram showing the relationship between the vehicle speed and the noise tolerance value according to other embodiments. [Figure 31] A time chart showing the temperature rise control mode according to other embodiments. [Figure 32] A time chart showing the temperature rise control mode according to other embodiments. [Figure 33] A time chart showing the temperature rise control mode according to other embodiments. [Figure 34] A time chart showing the temperature rise control mode according to other embodiments. [Figure 35] A time chart showing the temperature rise control mode according to other embodiments. [Figure 36] A diagram showing the power converter according to other embodiments. [Figure 37] A diagram showing the power converter according to other embodiments.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment in which the control device according to the present invention is embodied will be described with reference to the drawings. The control device of this embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle.

[0011] As shown in Figure 1, the system comprises a rotating electric machine 10 and an inverter 20 acting as a "power converter". The rotating electric machine 10 is a brushless synchronous machine, and in this embodiment, it is a permanent magnet synchronous machine. The rotating electric machine 10 comprises a rotor (not shown) and stator windings consisting of U, V, and W phase coils 11U, 11V, and 11W. The rotor is capable of transmitting power to the vehicle's drive wheels. In other words, the rotating electric machine 10 is the power source for the vehicle's movement.

[0012] The inverter 20 is equipped with a series connection of U, V, W phase upper arm switches SUH, SVH, SWH and U, V, W phase lower arm switches SUL, SVL, SWL. In each phase, the first end of the coil of the rotating electric machine 10 is connected to the low-potential terminal of the upper arm switch and the high-potential terminal of the lower arm switch. The second ends of the U, V, W phase coils 11U, 11V, 11W are connected at the neutral point. In this embodiment, the U, V, W phase coils 11U, 11V, 11W are offset by 120° in electrical angle.

[0013] In this embodiment, each switch SUH, SUL, SVH, SVL, SWH, and SWL is a voltage-controlled semiconductor switching element, specifically an IGBT. Therefore, the high-potential terminal of the switch is the collector, and the low-potential terminal is the emitter. Each switch SUH, SUL, SVH, SVL, SWH, and SWL is connected in antiparallel to a freewheeling diode DUH, DUL, DVH, DVL, DWH, and DWL.

[0014] The system comprises a high-potential path 22H, a low-potential path 22L, a battery 30 as an "energy storage unit," and a smoothing capacitor 24. The battery 30 is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The battery 30 is, for example, a battery pack comprising a series connection of multiple battery cells. The positive terminal of the battery 30 is connected to the collectors of the upper arm switches SUH, SVH, and SWH via the high-potential path 22H. The negative terminal of the battery 30 is connected to the emitters of the lower arm switches SUL, SVL, and SWL via the low-potential path 22L. The intermediate sections of the high-potential path 22H and the low-potential path 22L are connected by the smoothing capacitor 24.

[0015] The system includes a cutoff switch 60 and an external charger 61. The positive terminal of the battery 30 is connected to the positive terminal side of the external charger 61 via the cutoff switch 60, and the negative terminal of the battery 30 is connected to the negative terminal side of the external charger 61 via the cutoff switch 60.

[0016] The system includes a battery monitoring device 40. The battery monitoring device 40 detects battery information including the terminal voltage of the storage battery 30, the current flowing through the storage battery 30, the temperature of the storage battery 30, and the state of charge (SOC) of the storage battery 30.

[0017] The system includes a current sensor 41, an angle sensor 42, an inverter temperature sensor 43, and a motor temperature sensor 44. The current sensor 41 detects the current of at least two phases of the phase current flowing through the rotating electric machine 10. The angle sensor 42 detects the rotation angle (electrical angle) of the rotor of the rotating electric machine 10. The inverter temperature sensor 43 detects the temperature of the inverter 20 (e.g., the temperature of the upper and lower arm switches). The motor temperature sensor 44 detects the temperature of the rotating electric machine 10 (e.g., the temperature of the coils). The detected values ​​from each of the sensors 41-44 and the battery monitoring device 40 are input to the control device 50 of the system.

[0018] The control device 50 is mainly composed of a microcontroller 50a, which is equipped with a CPU. The functions provided by the microcontroller 50a can be provided by software recorded in a physical memory device and a computer that executes it, by software only, by hardware only, or by a combination thereof. For example, if the microcontroller 50a is provided by hardware electronic circuits, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcontroller 50a executes a program stored in a non-transitory tangible storage medium, which is its own storage unit 50b. The program includes, for example, a program for the processing shown in Figure 2. When the program is executed, the method corresponding to the program is executed. The storage unit 50b is, for example, a non-volatile memory. The program stored in the storage unit 50b can be updated via a network such as the Internet, such as OTA (Over The Air).

[0019] The control device 50 controls the switching of each switch SUH to SWL that make up the inverter 20 based on the input detected value in order to control the control amount (e.g., torque) of the rotating electric machine 10 to a command value. As a result, the rotor of the rotating electric machine 10 rotates and the vehicle can be driven.

[0020] When the vehicle is stopped and the rotor rotation has stopped, the control device 50 performs temperature-raising control to raise the temperature of the storage battery 30 by switching control of the inverter 20. The temperature-raising control in this embodiment is a control that enhances the temperature-raising capacity of the storage battery 30 while suppressing the noise generated by the rotating electric machine 10 in conjunction with this control. The temperature-raising control will be described below with reference to Figure 2. The process shown in Figure 2 is executed repeatedly, for example, at a predetermined control cycle.

[0021] In step S10, the inverter command frequency finv* is set. The specified period Tinv, which is the reciprocal of the inverter command frequency finv*, is the period of one cycle consisting of the coil charging mode, recirculation mode, coil discharge mode, and recirculation mode, which will be described later. The method for setting the inverter command frequency finv* is described below.

[0022] As shown in Figure 1, the current flowing from the high-potential path 22H towards the upper arm switch beyond the connection point with the smoothing capacitor 24 is defined as the inverter current Iinv (corresponding to the "switch-side current"), the current flowing to the battery 30 is defined as the battery current Ibat, and the current flowing to the smoothing capacitor 24 is defined as the capacitor current Ic. The inverter current Iinv is considered positive in the direction from the connection point with the smoothing capacitor 24 towards the upper arm switch, the battery current Ibat is considered positive on the discharge side, and the capacitor current Ic is considered positive in the direction from the high-potential path 22H towards the low-potential path 22L. The circuit including the battery 30, smoothing capacitor 24, inverter 20, high-potential path 22H, and low-potential path 22L is represented as the equivalent circuit shown in Figure 3. In the equivalent circuit, the inverter 20 is considered an AC current source that outputs an AC current of frequency finv. In Figure 3, Lbat represents the inductance of the battery 30, Rbat represents the internal resistance of the battery 30, and C represents the capacitance of the smoothing capacitor 24.

[0023] In this case, the frequency response characteristic of the battery current Ibat with respect to the inverter current Iinv is given by equation (eq1) below, and the frequency response characteristic of the ratio of the amplitude of the battery current Ibat to the amplitude of the inverter current Iinv is shown in Figure 4. Note that in equation (eq1) below, "ω = 2π × finv", and j is an imaginary number. In this characteristic, the amplitude ratio is approximately constant in the first frequency range from 0 Hz to a predetermined frequency, monotonically increases in the second frequency range following the higher frequency side of the first frequency range, and monotonically decreases in the third frequency range following the higher frequency side of the second frequency range.

[0024]

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[0025] Returning to the explanation of Figure 2, in step S11, the noise tolerance value Smax is set. The noise tolerance value Smax is the allowable level of noise generated by the rotating electric machine 10 in conjunction with the switching control of the inverter 20 during temperature rise control.

[0026] The noise tolerance value Smax may be made variable based on the inverter command frequency finv* set in step S10. In this case, for example, as shown in Figure 5, map information of the inverter command frequency finv* and the noise tolerance value Smax defined according to the equal loudness curve may be stored in the storage unit 50b. The noise tolerance value Smax is set based on this map information and the inverter command frequency finv*.

[0027] Returning to the explanation of Figure 2, in step S12, the target temperature Tbat* (e.g., 25°C) of the battery 30 is obtained. For example, the target temperature Tbat* is obtained from the battery monitoring device 40.

[0028] In step S13, the temperature of the storage battery 30 (hereinafter referred to as the battery temperature Tbatr) is obtained from the battery monitoring device 40. Then, it is determined whether the obtained battery temperature Tbatr is less than the target temperature Tbat*. If it is determined that the battery temperature Tbatr is less than the target temperature Tbat*, then the temperature rise control of the storage battery 30 is executed in steps S14 to S18. Note that the processing in step S13 corresponds to the "determination unit," and the processing in steps S14 to S18 corresponds to the "temperature rise control unit."

[0029] Figure 6 shows the relationship between the temperature of the battery 30, the maximum dischargeable power Woutlim, and the maximum chargeable power Winlim. The maximum dischargeable power Woutlim and the maximum chargeable power Winlim depend on the temperature of the battery 30, and tend to decrease as the temperature decreases. For this reason, after the temperature rise control is started, the temperature rise control is continued until it is determined in step S13 that the battery temperature Tbatr has reached the target temperature Tbat*.

[0030] Returning to the explanation of Figure 2, step S14 performs the calculation of the commanded effective current value Ibatrms*, which is the commanded effective current value to be supplied to the storage battery 30. This calculation process will be explained below using Figure 7.

[0031] In step S20, the battery heating power Pheat is set. In this embodiment, when the cutoff switch 60 is off and the external charger 61 is not connected to the storage battery 30, the battery heating power Pheat is set to the dischargeable power Wb of the storage battery 30 (specifically, for example, the maximum dischargeable power Woutlim). On the other hand, when the cutoff switch 60 is on and the external charger 61 and storage battery 30 are connected and external charging is in progress, the battery heating power Pheat is set to the sum of the dischargeable power Wb of the storage battery 30 and the outputable power Wc of the external charger 61.

[0032] In step S21, the internal resistance Rbat of the storage battery 30 is estimated based on the battery temperature Tbatr and SOC obtained from the battery monitoring device 40. For example, the internal resistance Rbat may be estimated based on map information in which the internal resistance Rbat is defined in relation to the battery temperature Tbatr and SOC.

[0033] The internal resistance Rbat changes depending on the frequency of the current flowing through the battery 30. Therefore, the map information may be information in which the internal resistance Rbat is defined in relation to the battery temperature Tbatr, SOC, and inverter command frequency finv*. In this case, the internal resistance Rbat can be estimated based on this map information, inverter command frequency finv*, battery temperature Tbatr, and SOC.

[0034] In step S22, the commanded battery current RMS value Ibatrms* is calculated based on the set battery heating power Pheat and the estimated internal resistance Rbat. Specifically, considering the relationship "power = resistance × current^2", the commanded battery current RMS value Ibatrms* can be calculated based on the following equation (eq2).

[0035]

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[0036] Returning to the explanation of Figure 2, in the following step S15, the commanded inverter current RMS value Iinvrms*, which is the commanded value of the RMS value of the inverter current Iinv, is calculated based on the inverter command frequency finv* and the commanded battery current RMS value Ibatrms*. Specifically, in the response characteristics shown in Figure 4, when the commanded battery current RMS value Ibatrms* calculated in step S14 is used as the numerator, the value in the denominator that realizes the value on the vertical axis corresponding to the inverter command frequency finv* is calculated as the commanded inverter current RMS value Iinvrms*. This makes it possible to increase the heating capacity of the battery 30 while minimizing the amount of current exchanged between the battery 30 and the coil of the rotating electric machine 10.

[0037] In step S16, the command current average value Imgave* and the command current change amount ΔI* are calculated. The command current average value Imgave* is the command value of the time average value of the current flowing through the coil in one cycle of temperature rise control. The command current change amount ΔI* is the command value of the change in current flowing through the coil during the execution period of the coil charging mode, which will be described later, within one cycle of temperature rise control. The command current average value Imgave* and the command current change amount ΔI* are determined using the effective value of the inverter current Iinv as the command inverter current effective value Iinvrms*, and so that the noise level generated by the rotating electric machine 10 in conjunction with the temperature rise control does not exceed the noise tolerance value Smax. The calculation methods for the command current average value Imgave* and the command current change amount ΔI* are described below.

[0038] In Figure 8, the coil current Img is the current with the largest absolute value among the currents flowing through each phase coil 11U, 11V, and 11W during temperature rise control. The direction from inverter 20 towards the neutral point is considered positive for the coil current Img. The time-averaged value of the coil current Img is defined as the average coil current value Imgave, and the change in the coil current Img is defined as the change in coil current ΔImg.

[0039] The noise generated by the rotating electric machine 10 during temperature control is caused by the vibration of the stator of the rotating electric machine 10 due to the change in magnetic force Δφ generated by the change in current flowing through the coil. The change in magnetic force Δφ is determined by the product of the coil inductance Lmg and the change in coil current ΔImg. Therefore, there is a positive correlation between the sound pressure level of the noise and the change in coil current ΔImg.

[0040] On the other hand, as the absolute value of the average coil current Imgave increases, the coil becomes magnetically saturated. This slightly reduces the coil's inductance Lmg. Therefore, even if the change in coil current ΔImg is the same, the larger the absolute value of the average coil current Imgave, the lower the sound pressure level of the noise. Consequently, the sound pressure level of the noise correlates with "ΔImg / Imgave". In the two-dimensional region defined by the average coil current Imgave and the change in coil current ΔImg, the contour lines of the sound pressure level are represented by the curve shown in Figure 9.

[0041] Next, we will explain the control modes that constitute one cycle of temperature rise control. The control modes are coil charging mode, recirculation mode, and coil discharge mode. Figure 10 shows the changes in coil current Img, inverter current Iinv, and d-axis current Id flowing through the coil in each mode. Note that Figure 10 shows the changes when the electrical angle is 0.

[0042] The coil charging mode is executed at times t1 to t2 in Figure 10. The coil charging mode is a control mode in which current flows from the smoothing capacitor 24 and the storage battery 30 to the coil via the inverter 20 (specifically, the upper arm switch of the inverter 20), as shown in Figure 11. In the coil charging mode, the upper arm switches of some of the phases are turned on, and the lower arm switches of at least one of the remaining phases are turned on. In the example shown in Figure 11, the U-phase upper arm switch SUH is turned on, and the V and W-phase lower arm switches SVL and SWL are turned on.

[0043] The coil charging mode is a control mode that outputs a constant d-axis voltage based on the electrical angle θ detected by the angle sensor 42. In this case, as shown in Figure 10, the absolute values ​​of the coil current Img and the d-axis current Id gradually increase, until the absolute value of the inverter current Iinv and the absolute value of the coil current Img become equal. In this case, the polarity of the inverter current Iinv is positive. Note that in Figure 10, the inverter current Iinv and the coil current Img in the coil charging mode are shown slightly offset for clarity.

[0044] The freewheel mode is executed at times t2 to t3 in Figure 10. The freewheel mode is a control mode in which current is circulated through a circuit including the switch and coil of one of the upper or lower arms of the inverter 20, as shown in Figure 12. During the execution period of the freewheel mode, the inverter current Iinv becomes 0. In freewheel mode, all phase switches constituting one of the upper or lower arms of the inverter 20 are turned off, and at least one phase switch constituting the other arm is turned on. In the example shown in Figure 12, all phases of the upper arm switches are turned off, and all phases of the lower arm switches are turned on. Note that the switches of the phases through which current flows to the freewheel diode may also be turned off.

[0045] In freewheel mode, the output voltage of inverter 20 becomes 0. Also, neglecting conduction losses, the coil current Img and d-axis current Id become constant, and the inverter current Iinv becomes 0.

[0046] The coil discharge mode is executed at times t3 to t4 in Figure 10. The coil discharge mode is a control mode in which current flows from the coil through the inverter 20 to the smoothing capacitor 24 and the storage battery 30, as shown in Figure 13. In the coil discharge mode of this embodiment, all phase upper and lower arm switches are turned off.

[0047] The coil discharge mode is a control mode that outputs a d-axis voltage that has the same magnitude as the d-axis voltage in the coil charging mode, but with the opposite polarity, based on the electrical angle θ. In this case, as shown in Figure 10, the absolute values ​​of the coil current Img, the d-axis current Id, and the inverter current Iinv gradually decrease, until the absolute value of the inverter current Iinv becomes equal to the absolute value of the coil current Img. In this case, the polarity of the inverter current Iinv is negative.

[0048] In this embodiment, in both the coil charging mode and the coil discharging mode, only the d-axis voltage is output among the d and q-axis voltages. This prevents q-axis current from flowing through the coil and prevents the rotor from rotating during temperature control.

[0049] Figure 14 will be used to explain one cycle of temperature rise control in more detail. Tinv shown in Figure 14 is the specified period described above, and is the reciprocal of the inverter command frequency finv*. One cycle of temperature rise control is repeatedly executed at each specified period. Here, the specified period Tinv is divided into two equal parts: the first half period and the second half period. In the first half period (Tinv / 2), the control device 50 sequentially executes the coil charging mode and the recirculation mode (corresponding to the "first recirculation mode"). In the first half period, the execution time of the coil charging mode is defined as the charging execution time tchr, and the execution time of the recirculation mode is defined as the first recirculation execution time tzchr. In the second half period, the control device 50 sequentially executes the coil discharge mode and the recirculation mode (corresponding to the "second recirculation mode"). In the second half period, the execution time of the coil discharge mode is defined as the discharge execution time tdis, and the execution time of the recirculation mode is defined as the second recirculation execution time tzdis.

[0050] In this case, assume that a current fluctuation occurs with respect to the average coil current value Imgave by a change in coil current ΔImg. Also, the charging execution time tchr and the discharging execution time tdis are expressed as tact. In this case, the effective value of the inverter current Iinv (hereinafter, the effective value of the inverter current Iinvrms) is equal to the effective value of the coil current when the current flowing through the coil is equal to the average coil current value Imgave for tact during a period of Tinv / 2, and is therefore expressed by the following equation (eq3).

[0051]

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[0052]

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[0053]

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[0054] When the contour lines shown in Figure 15 and the contour lines shown in Figure 9 are plotted on a single two-dimensional region, the result is as shown in Figure 16. In Figure 16, the dashed line CLsmax represents the contour line in Figure 9, and the solid line CLinnvrms represents the contour line in Figure 15. When the noise tolerance value Smax is determined, the contour line CLsmax is determined, and when the inverter current RMS value Iinvrms is determined, the contour line CLinnvrms is determined. In this case, in the two-dimensional region, the average coil current value Imgave that defines the intersection point P of the contour lines CLsmax and CLinnvrms becomes the command current average value Imgave*, and the coil current change ΔImg that defines the intersection point P becomes the command current change ΔI*.

[0055] In other words, the control device 50 calculates the command current average value Imgave* and the command current change amount ΔI* based on the noise tolerance value Smax and the command inverter current RMS value Iinvrms*. Specifically, map information in which the command current average value Imgave* and the command current change amount ΔI* are defined in relation to the noise tolerance value Smax and the command inverter current RMS value Iinvrms* is stored in the storage unit 50b. The control device 50 calculates the command current average value Imgave* and the command current change amount ΔI* based on this map information, the noise tolerance value Smax set in step S11, and the command inverter current RMS value Iinvrms* calculated in step S15.

[0056] As shown in Figure 17, the larger the noise tolerance value Smax and the effective command inverter current value Iinvrms*, the larger the command current change amount ΔI* should be set. Also, as shown in Figure 18, the larger the effective command inverter current value Iinvrms*, the larger the command current average value Imgave* should be set. Also, as shown in Figure 19, the larger the noise tolerance value Smax, the smaller the command current average value Imgave* should be set.

[0057] Returning to the explanation of Figure 2, in the following step S17, the charging execution time tchr, the first recirculation execution time tzchr, the discharge execution time tdis, and the second recirculation execution time tzdis for one cycle are calculated. The calculation methods for each time are explained below with reference to Figure 20.

[0058] Let ΔIchr be the change in coil current Img during the charging time tchr from time t1 to t2 in Figure 20, and let ΔIzchr be the change in coil current Img during the first recirculation time tzchr from time t2 to t3. Also, let ΔIdis be the change in coil current Img during the discharge time tdis from time t3 to t4, and let ΔIzdis be the change in coil current Img during the second recirculation time tzdis from time t4 to t5. In this case, equations (eq6) to (eq12) below hold.

[0059]

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[0060]

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[0061]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070] In light of the above equation (eq14), as shown in Figure 22, the longer the charging execution time tchr and the higher the inverter command frequency finv*, the shorter the first recirculation execution time tzchr should be.

[0071] In light of the above equation (eq15), as shown in Figure 23, the larger the command current change ΔI*, the longer the discharge execution time tdis. Also, as shown in Figure 24, the larger the command current average value Imgave*, the shorter the discharge execution time tdis. Furthermore, the higher the terminal voltage Vbatr of the storage battery 30, the shorter the discharge execution time tdis.

[0072] In light of the above equation (eq16), as shown in Figure 25, the longer the discharge execution time tdis and the higher the inverter command frequency finv*, the shorter the second recirculation execution time tzdis should be.

[0073] In this embodiment, the charging execution time tchr in a specified period Tinv is longer than the discharging execution time tdis. This setting is based on the consideration that losses occur due to the circulation of current in the recirculation mode.

[0074] Returning to the explanation of Figure 2, in the following step S18, the switching control of the inverter 20 is performed to repeat the above cycle based on the command current average value Imgave* and command current change amount ΔI* calculated in step S16, and the respective times tchr, tzchr, tdis, tzdis and electrical angle θ calculated in step S17. At this time, in the coil charging mode and coil discharging mode, the d-axis voltage output by the inverter 20 is achieved by adjusting the execution time of each of the two switching patterns according to the electrical angle θ.

[0075] More specifically, as shown in Figure 26, the vector space consisting of the U-phase voltage vector (100), the V-phase voltage vector (010), and the W-phase voltage vector (001), which are shifted by 120 degrees in electrical angle, is divided into six sectors at 60° intervals in electrical angle. Figure 27 shows the switching patterns of the upper and lower arm switches for each phase when realizing voltage vectors (110), (011), and (101) in addition to voltage vectors (100), (010), and (001).

[0076] The d-axis voltage is realized based on information about which sector the current electrical angle θ belongs to, and two effective voltage vectors that divide that sector and have a phase difference of 60 degrees. The following explanation will use the case where the current electrical angle θ belongs to sector 1 as an example.

[0077] Assume that the d-axis voltage vector of inverter 20 belongs to sector 1, and that the d-axis voltage vector is located at a position rotated counterclockwise by θ from the voltage vector (100). In coil charging mode, the output d-axis voltage vector can be realized as a composite vector of voltage vector (100)Vt1 and voltage vector (110)Vt2, as shown in Figure 28. Therefore, the d-axis voltage vector can be output by adjusting the ratio of the appearance time of voltage vector (100) and the appearance time of voltage vector (110) according to the electrical angle θ. Here, "appearance time of (100) : appearance time of (110) = sin(60°-θ) : sinθ". Also, "appearance time of (100) + appearance time of (110) = tchr".

[0078] On the other hand, the d-axis voltage vector output in coil discharge mode has a phase difference of 180 degrees from the d-axis voltage vector output in coil charging mode. Therefore, the d-axis voltage vector output in coil discharge mode is a vector located at a position rotated counterclockwise by θ from the voltage vector (011) in sector 4, and can be realized as a composite vector of voltage vector (011) and voltage vector (001). Therefore, the d-axis voltage vector can be output by adjusting the ratio of the appearance time of voltage vector (011) to the appearance time of voltage vector (001) according to the electrical angle θ. Here, "appearance time of (011) : appearance time of (001) = sin(60°-θ) : sinθ". Also, "appearance time of (011) + appearance time of (001) = tdis".

[0079] In the embodiment described in detail above, the switching control of the inverter 20 is performed so that the absolute value of the current flowing through the coil is greater than 0 in one cycle consisting of a coil charging mode, a recirculation mode, a coil discharge mode, and a recirculation mode. As a result, the DC component included in the current flowing through the coil can be increased, and the charge and discharge current of the storage battery 30 can be increased in the coil charge and discharge mode. As a result, the heating capacity of the storage battery 30 can be increased.

[0080] Furthermore, by increasing the DC component mentioned above, the heating capacity of the battery 30 is enhanced, making it possible to increase the charging and discharging current of the battery 30 without increasing the amount of change in the current flowing through the coil. This makes it possible to suppress the noise level generated in the rotating electric machine 10 in conjunction with the switching control by the heating control unit.

[0081] Thus, according to this embodiment, the storage battery 30 can be heated up quickly while suppressing noise.

[0082] In coil charge / discharge mode, if the rate of change of coil current Img is high, there is a concern that the amount of change in coil current ΔImg in a specified period Tinv will significantly exceed the amount of change in command current ΔI*. In this regard, one cycle of this embodiment includes a recirculation mode. Therefore, even if the rate of change of coil current Img is high, it is possible to prevent the amount of change in coil current ΔImg in a specified period Tinv from significantly exceeding the amount of change in command current ΔI*. As a result, noise can be accurately suppressed in temperature rise control.

[0083] <Other Embodiments> The above embodiment may be implemented with the following modifications.

[0084] The control device 50 may perform switching control of the inverter 20 so that a strengthening field current (Id>0) flows as the d-axis current during temperature rise control. Figure 29 shows the trajectory of the d,q axis currents Id,Iq over one cycle in this case, and the trajectory when a weakening field current (Id<0) flows as the d-axis current. Even if a q-axis current flows and torque is generated due to some factor such as sensor detection error or control error m, the torque fluctuation amount in the case of a strengthening field current can be made smaller than the torque fluctuation amount in the case of a weakening field current. As a result, discomfort to the user associated with temperature rise control can be suppressed.

[0085] The battery current and inverter current information used in the processing shown in Figures 2 and 7 is not limited to the effective current value; for example, it may also be the current amplitude.

[0086] As shown in Figure 30, the control device 50 may set a lower noise tolerance value Smax as the vehicle's travel speed Vs decreases. This is because the noise generated by the rotating electric machine 10 becomes more noticeable to the user as the travel speed Vs decreases. This setting may be implemented, for example, during coasting, which is the vehicle's inertial movement.

[0087] In one cycle, the coil charging mode, the recirculation mode, and the coil discharge mode may be divided into N (where N is an integer of 2 or more) parts. Figure 31 shows an example where it is divided into two parts. In this case, in the coil charging mode, the sum of the divided charging execution times tcr1 and tcr2 should be equal to the charging execution time tchr calculated in step S17. Also, in the recirculation mode following the coil charging mode, the sum of the divided first recirculation execution times tzcr1 and tzcr2 should be equal to the first recirculation execution time tzchr calculated in step S17. On the other hand, in the coil discharge mode, the sum of the divided discharge execution times tds1 and tds2 should be equal to the discharge execution time tdis calculated in step S17. Also, in the recirculation mode following the coil discharge mode, the sum of the divided second recirculation execution times tzds1 and tzds2 should be equal to the second recirculation execution time tzdis calculated in step S17.

[0088] As shown in Figure 32, a recirculation mode may be implemented in which the coil charging mode and the coil discharging mode are repeated at a period shorter than Tinv / 2. Even in this case, the current flowing through the coil can be maintained.

[0089] As shown in Figure 33, one cycle of temperature rise control may not include a recirculation mode, and one cycle may consist of a coil charging mode and a coil discharging mode.

[0090] In each of the above embodiments, the command current average value Imgave* may change over time. Figures 34 and 35 show an example in which one cycle shown in Figure 33 is repeated.

[0091] In the above embodiment, the control device 50 repeated one cycle of temperature rise control without reducing the current flowing through the coil to zero until it determined that the battery temperature Tbatr had reached the target temperature Tbat*, but it is not limited to this. For example, the control device 50 may provide a period between repeated temperature rise control cycles in which it stops the switching control of the inverter 20 and temporarily reduces the current flowing through the coil to zero.

[0092] The rechargeable and dischargeable energy storage unit is not limited to a battery; it may also be a large-capacity capacitor, such as an electric double-layer capacitor.

[0093] In light of the temperature dependence of the internal resistance Rbat and d-axis inductance, the control device 50 may correct the command current average value Imgave* and the command current change amount ΔI* based on the detection value of at least one of the inverter temperature sensor 43 and the motor temperature sensor 44.

[0094] The specified period Tinv is not limited to being set for the same period during temperature rise control; it may be changed during temperature rise control. For example, the specified period Tinv may be changed every cycle.

[0095] The power converter is not limited to a multiphase inverter; for example, it may be a full-bridge circuit 70 as shown in Figure 36 or a DC-DC converter 80 as shown in Figure 37. These two configurations will be described below. Note that in Figures 36 and 37, the configuration of the control device 50 and other components shown in Figure 1 has been omitted.

[0096] The full-bridge circuit 70 shown in Figure 36 comprises a series connection of a first upper arm switch SAH and a first lower arm switch SAL, and a series connection of a second upper arm switch SBH and a second lower arm switch SBL. In Figure 36, the IGBTs of each switch SAH, SAL, SBH, and SBL are shown in a simplified manner. Freewheeling diodes DAH, DAL, DBH, and DBL are connected in antiparallel to each switch SAH, SAL, SBH, and SBL. Each switch SAH, SAL, SBH, and SBL is switched by a control device (not shown).

[0097] The full-bridge circuit 70 includes a smoothing capacitor 71 and a coil 72. The coil 72 connects the connection point of the first upper arm switch SAH and the first lower arm switch SAL to the connection point of the second upper arm switch SBH and the second lower arm switch SBL.

[0098] An example of temperature rise control performed by the control device is described below. In one cycle of temperature rise control, the coil charging mode is a mode in which the first upper arm switch SAH and the second lower arm switch SBL are turned on, and the first lower arm switch SAL and the second upper arm switch SBH are turned off. The recirculation mode following the coil charging mode is a mode in which the first upper arm switch SAH is turned on, or a mode in which the second lower arm switch SBL is turned on, among the switches SAH, SAL, SBH, and SBL. The coil discharge mode following the recirculation mode is a mode in which the switches SAH, SAL, SBH, and SBL are turned off. The recirculation mode following the coil discharge mode is the same as the recirculation mode following the coil charging mode. By repeating the cycle described above, the storage battery 30 can be rapidly heated up while suppressing the noise generated in the coil 72 during temperature rise control.

[0099] Next, the DC-DC converter 80 shown in Figure 37 will be described. The DC-DC converter 80 is a boost chopper circuit and comprises a series connection of a first upper arm switch S1H and a first lower arm switch S1L, and a series connection of a second upper arm switch S2H and a second lower arm switch S2L. In Figure 37, the IGBT switches S1H, S1L, S2H, and S2L are shown in a simplified manner. Freewheeling diodes D1H, D1L, D2H, and D2L are connected in antiparallel to each of the switches S1H, S1L, S2H, and S2L. Each of the switches S1H, S1L, S2H, and S2L is switched by a control device (not shown).

[0100] The DC-DC converter 80 includes a first smoothing capacitor 81, a second smoothing capacitor 82, a first coil 83, and a second coil 84. The first coil 83 connects the connection point of the first upper arm switch S1H and the first lower arm switch S1L to one end of the second smoothing capacitor 82. The second coil 84 connects the connection point of the second upper arm switch S2H and the second lower arm switch S2L to one end of the second smoothing capacitor 82.

[0101] An example of temperature rise control performed by the control device is described below. The series connection of the first coil 83 and the second coil 84 in Figure 37 can be considered as coil 72 in Figure 36. In one cycle of temperature rise control, the coil charging mode is a mode in which the first upper arm switch S1H and the second lower arm switch S2L are turned on, and the first lower arm switch S1L and the second upper arm switch S2H are turned off. The recirculation mode following the coil charging mode is a mode in which the first upper arm switch S1H is turned on, or a mode in which the second lower arm switch S2L is turned on, among the switches S1H, S1L, S2H, S2L. The coil discharge mode following the recirculation mode is a mode in which the switches S1H, S1L, S2H, S2L are turned off. The recirculation mode following the coil discharge mode is the same as the recirculation mode following the coil charging mode. By repeating the cycle described above, the battery 30 can be rapidly heated while suppressing the noise generated in the first and second coils 83 and 84 during the temperature rise control. Note that the recirculation mode may be omitted from the temperature rise control cycle described in Figures 36 and 37.

[0102] The rotating electric machine is not limited to a permanent magnet field type synchronous machine; for example, it may be a wound field type synchronous machine equipped with field windings on the rotor. In this case, the control device 50 may, during temperature rise control, apply a q-axis voltage to the coil in addition to the d-axis voltage, while controlling the field current flowing through the field winding to zero. Since the field current becomes zero, even if a q-axis current flows through the coil in conjunction with the application of the q-axis voltage, no torque is generated. As a result, it is possible to prevent the rotor from rotating in conjunction with the temperature rise control. Furthermore, the rotating electric machine is not limited to a synchronous machine.

[0103] The vehicle is equipped with a braking device (e.g., a handbrake) that applies braking torque to the vehicle's wheels (drive wheels). The control device 50 may apply a q-axis voltage to the coil in addition to the d-axis voltage, provided that braking torque is applied to the wheels by the braking device so that the wheels do not rotate.

[0104] The inverter switch is not limited to IGBTs; for example, it may be an N-channel MOSFET with a built-in body diode. In this case, the high-potential terminal becomes the drain, and the low-potential terminal becomes the source.

[0105] The rotating electric machine is not limited to a star connection; a delta connection is also acceptable.

[0106] The mobile device on which the system is mounted is not limited to a vehicle; for example, it could be an aircraft or a ship. Furthermore, the system is not limited to being mounted on a mobile device; it could be a stationary system.

[0107] The control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. [Explanation of symbols]

[0108] 10... Rotating electric machine, 20... Inverter, 30... Storage battery, 50... Control device.

Claims

1. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, In a control device (50) for a power converter applied to a system comprising: A determination unit that determines whether or not it is necessary to raise the temperature of the energy storage unit, When the determination unit determines that the energy storage unit needs to be heated, the temperature rise control unit controls the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero in each cycle, while repeatedly generating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, a coil discharge mode which follows the coil charging mode in which the magnitude of the current flowing through the coil is gradually decreased, and a recirculation mode which maintains the magnitude of the current flowing through the coil. Equipped with, A control device for a power converter, wherein the execution time of the coil charging mode (tchr) in the specified period is longer than the execution time of the coil discharge mode (tdis).

2. The aforementioned system, A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, The system includes smoothing capacitors (24, 71, 81) that electrically connect the high-potential path and the low-potential path, If the current flowing on the upper arm switch side of the high-potential side path, beyond the connection point with the smoothing capacitor, is defined as the switch-side current (I inv), and the switch-side current flowing toward the upper arm switch is defined as positive, then the coil charging mode is a mode in which the magnitude of the switch-side current and the magnitude of the current flowing through the coil are gradually increased while the positive polarity switch-side current flows through it. The aforementioned return mode is a mode in which the magnitude of the current flowing through the coil is maintained while the magnitude of the switch-side current is set to zero. The control device for a power converter according to claim 1, wherein the coil discharge mode is a mode in which a negative polarity switch-side current is passed through while gradually decreasing the magnitude of the switch-side current and the magnitude of the current passed through the coil.

3. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a control device (50) for a power converter applied to a system comprising: A determination unit that determines whether or not it is necessary to raise the temperature of the energy storage unit, When the determination unit determines that it is necessary to raise the temperature of the energy storage unit, the temperature rise control unit controls the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode which is a mode after the coil charging mode in which the magnitude of the current flowing through the coil is gradually decreased. Equipped with, A control device for a power converter, wherein the specified period is set to a period corresponding to a frequency range in the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, where the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side of the connection point with the smoothing capacitor (Iinv) exceeds 1.

4. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a control device (50) for a power converter applied to a system comprising: A determination unit that determines whether or not it is necessary to raise the temperature of the energy storage unit, When the determination unit determines that it is necessary to raise the temperature of the energy storage unit, the temperature rise control unit controls the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode which is a mode after the coil charging mode in which the magnitude of the current flowing through the coil is gradually decreased. Equipped with, In the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side than the connection point with the smoothing capacitor (Iinv) is approximately constant in a first frequency range from 0 Hz to a predetermined frequency, monotonically increases in a second frequency range following the high-frequency side of the first frequency range, and monotonically decreases in a third frequency range following the high-frequency side of the second frequency range. A control device for a power converter, wherein the specified period is set to a period corresponding to a frequency range where the ratio is greater than the ratio at 1 Hz of the frequency characteristic.

5. The coils (11U to 11W) are coils that constitute the rotating electric machine (10), The power converter control device according to any one of claims 1 to 4, wherein the temperature rise control unit performs the switching control so that the rotating electric machine does not generate torque due to the current flowing through the coil.

6. The power converter control device according to claim 5, wherein the temperature rise control unit performs the switching control such that the d-axis current among the d-axis current and q-axis current flows to the coil.

7. The power converter control device according to claim 5 or 6, wherein the temperature rise control unit performs the switching control so that a strengthening field current flows as the d-axis current.

8. The power converter control device according to any one of claims 1 to 7, wherein the temperature rise control unit sets the amount of change in the coil current in one cycle so that the noise level generated in conjunction with the switching control by the temperature rise control unit does not exceed the noise tolerance value (Smax).

9. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, In a control device (50) for a power converter applied to a system comprising: A determination unit that determines whether or not it is necessary to raise the temperature of the energy storage unit, When the determination unit determines that it is necessary to raise the temperature of the energy storage unit, the temperature rise control unit controls the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode which is a mode after the coil charging mode in which the magnitude of the current flowing through the coil is gradually decreased. Equipped with, The temperature rise control unit sets the amount of current change in the coil in one cycle so that the noise level generated by the switching control by the temperature rise control unit does not exceed the noise tolerance value (Smax). An acquisition unit that acquires current information, which is information about the effective value or current amplitude of the current flowing from the energy storage unit to the power converter, The system includes a storage unit (50b) that stores information relating the command current average value (Imgave*), which is the command value of the time average value of the current flowing through the coil when the coil charging mode and the coil discharging mode are repeated, the command current change amount (ΔI*), which is the command value of the change amount of the current flowing through the coil in the coil charging mode, the current information and the noise tolerance value. The temperature rise control unit calculates the command current average value and the command current change amount based on the current information acquired by the acquisition unit and the stored information of the storage unit, and performs the switching control based on the calculated command current average value and the command current change amount, thereby controlling the power converter.

10. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and In a program applied to a system that includes the following features, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that it is necessary to raise the temperature of the energy storage unit, a temperature rise control process is performed by repeatedly generating a cycle at a predetermined period, which includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, and a recirculation mode in which the magnitude of the current flowing through the coil is maintained, while controlling the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than 0 in each cycle. Make it run, A program in which the execution time of the coil charging mode (tchr) in the specified period is longer than the execution time of the coil discharging mode (tdis).

11. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a program applied to a system that includes the following features, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, Make it run, A program in which the specified period is set to a period corresponding to a frequency range in which, in the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side than the connection point with the smoothing capacitor (Iinv) exceeds 1.

12. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a program applied to a system that includes the following features, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, Make it run, In the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side than the connection point with the smoothing capacitor (Iinv) is approximately constant in a first frequency range from 0 Hz to a predetermined frequency, monotonically increases in a second frequency range following the high-frequency side of the first frequency range, and monotonically decreases in a third frequency range following the high-frequency side of the second frequency range. A program in which the specified period is set to a period corresponding to a frequency range where the ratio is greater than the ratio at 1 Hz of the frequency characteristic.

13. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and Memory unit (50b) and In a program applied to a system that includes the following features, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, A process for acquiring current information, which is information about the effective value or current amplitude of the current flowing from the energy storage unit to the power converter, Make it run, In the temperature rise control process, the amount of change in the coil current in one cycle is set so that the noise level generated by the switching control due to the temperature rise control process does not exceed the noise tolerance value (Smax). The storage unit stores information relating the command current average value (Imgave*), which is the command value of the time average value of the current flowing through the coil when the coil charging mode and the coil discharging mode are repeated, the command current change amount (ΔI*), which is the command value of the change in the amount of current flowing through the coil in the coil charging mode, the current information, and the noise tolerance value. A program that, in the temperature rise control process, calculates the command current average value and the command current change amount based on the acquired current information and the stored information of the storage unit, and performs the switching control based on the calculated command current average value and the command current change amount.

14. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and In a control method applied to a system comprising, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that it is necessary to raise the temperature of the energy storage unit, a temperature rise control process is performed by repeatedly generating a cycle at a predetermined period, which includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, and a recirculation mode in which the magnitude of the current flowing through the coil is maintained, while controlling the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than 0 in each cycle. Make it run, A control method wherein the execution time of the coil charging mode (tchr) in the prescribed cycle is longer than the execution time of the coil discharge mode (tdis).

15. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a control method applied to a system comprising, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, Make it run, A control method wherein the specified period is set to a period corresponding to a frequency range in which, in the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side than the connection point with the smoothing capacitor (Iinv) exceeds 1.

16. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and A high-potential side path (22H) electrically connects the positive electrode side of the energy storage unit to the high-potential side terminal of the upper arm switches (SUH to SWH, SAH, SBH, S1H, S2H) that constitute the power converter, A low-potential side path (22L) electrically connects the negative electrode side of the energy storage unit to the low-potential side terminal of the lower arm switches (SUL to SWL, SAL, SBL, S1L, S2L) that constitute the power converter, A smoothing capacitor (24, 71, 81) electrically connects the high-potential path and the low-potential path, In a control method applied to a system comprising, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, Make it run, In the frequency characteristics of the circuit including the energy storage unit, the smoothing capacitor, the power converter, the high-potential side path, and the low-potential side path, the ratio of the current flowing through the energy storage unit (Ibat) to the current flowing through the high-potential side path on the upper arm switch side than the connection point with the smoothing capacitor (Iinv) is approximately constant in a first frequency range from 0 Hz to a predetermined frequency, monotonically increases in a second frequency range following the high-frequency side of the first frequency range, and monotonically decreases in a third frequency range following the high-frequency side of the second frequency range. A control method in which the specified period is set to a period corresponding to a frequency range in which the ratio is larger than the ratio at 1 Hz of the frequency characteristic.

17. A rechargeable and dischargeable energy storage unit (30), Coils (11U-11W, 72, 83, 84) and A power converter (20, 70, 80) electrically connects the coil and the energy storage unit, Computer (50a) and Memory unit (50b) and In a control method applied to a system comprising, To the aforementioned computer, A determination process to determine whether or not it is necessary to raise the temperature of the energy storage unit, If the determination process determines that the energy storage unit needs to be heated, a temperature-raising control process is performed to control the switching of the power converter so that the magnitude of the current flowing through the coil becomes greater than zero, while repeatedly creating a cycle at a predetermined period (Tinv) that includes a coil charging mode in which the magnitude of the current flowing through the coil is gradually increased, and a coil discharge mode in which the magnitude of the current flowing through the coil is gradually decreased, A process for acquiring current information, which is information about the effective value or current amplitude of the current flowing from the energy storage unit to the power converter, Make it run, In the temperature rise control process, the amount of change in the coil current in one cycle is set so that the noise level generated by the switching control due to the temperature rise control process does not exceed the noise tolerance value (Smax). The storage unit stores information relating the command current average value (Imgave*), which is the command value of the time average value of the current flowing through the coil when the coil charging mode and the coil discharging mode are repeated, the command current change amount (ΔI*), which is the command value of the change in the amount of current flowing through the coil in the coil charging mode, the current information, and the noise tolerance value. A control method comprising: in the temperature rise control process, calculating the command current average value and the command current change amount based on the acquired current information and the stored information of the storage unit, and performing the switching control based on the calculated command current average value and the command current change amount.

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