JP6469364B2 - Control device and control method for electric vehicle - Google Patents

Description

  The present invention relates to a control device and a control method for an electric vehicle.

  In consideration of environmental problems and the like, development of electric vehicles such as electric vehicles and fuel cell vehicles that can be driven only by a motor (electric motor), and hybrid electric vehicles that use an engine and a motor as drive sources is progressing. Electric vehicles mainly use a three-phase motor as a motor as a drive source, and electric power is supplied to the motor via an inverter that converts a direct current from a battery power source into an alternating current. That is, when the motor outputs a driving force or a regenerative force, a direct current flows between the battery and the inverter, and a three-phase alternating current flows between the inverter and the motor.

  In this way, when current flows between the motor, inverter, and battery devices, electrical components such as electric wires, harnesses, and connectors that make up the power supply circuit between these devices can be squared and energized. It generates heat in proportion. For this reason, it is necessary for each electrical component to have a specification that can withstand the heat generation amount.

  For the purpose of protecting such electrical components and optimizing specifications, for example, Patent Document 1 discloses providing a current limit value based on an average output of direct current from each battery.

JP 2006-288030 A

  As in the technology of Patent Document 1, in a conventional electric vehicle, the output of a motor used as a drive source is lower than the capacity of the battery, and the electric component on the DC side between the battery and the inverter has durability against the heat generation. If it has, the safety | security as the whole electric drive device was fully securable.

  However, in recent years, from the viewpoint of further improving fuel efficiency and reducing exhaust gas, the motor tends to increase in output, that is, increase in current in order to increase the output ratio of the motor. If it does so, the influence of the heat_generation | fever with respect to the electrical component of the alternating current side between an inverter and a motor can no longer be disregarded. In particular, since the voltage of the three-phase current fluctuates depending on the rotation speed of the motor, there is no guarantee that the specifications of the AC-side electrical components are satisfied only by the DC-side current limitation between the battery and the inverter.

  In this way, the current limitation on the DC side of the inverter alone may not be able to suppress the heat generation within the allowable value of the thermal load corresponding to the specifications of the AC side electrical components. In order to ensure safety, it is necessary to use electrical components with significantly higher performance than originally required.

  Also, at the vehicle design stage, in order to select the electrical components to be used, a current profile that is expected to actually flow during vehicle travel is simulated so that the current during vehicle travel does not exceed the specifications of each electrical component. Etc.

  However, after the initial design stage, there may be a change in usage conditions such as relaxing the current limit on the DC side of the inverter to improve fuel efficiency. It was also necessary to review the electrical components on the AC side, which led to an increase in work man-hours. In addition, it is difficult to examine in advance all the usage conditions that are actually used while the vehicle is running, and there is a risk of omission of examination.

  The present invention has been made to solve such a problem, and the object of the present invention is to optimize the specifications of electric parts that are over-specification in the electric drive device, thereby reducing the size of the electric drive device. It is another object of the present invention to provide a control device and a control method for an electric vehicle that can reduce the cost, simplify the examination of the use conditions of the electrical components in the design stage, and improve the examination accuracy.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

(1) An electric vehicle control device according to this application example includes an electric motor that is a drive source of the vehicle and that can generate electric power, a battery that can store electric power for driving the electric motor, and the battery and the electric motor. An inverter that performs direct current and alternating current conversion, and a circuit that supplies electric power between the electric motor and the inverter, and a power supply circuit that includes a plurality of electrical components each having a predetermined thermal load tolerance; , the current value in the power supply circuit, so as not to exceed the Jo Tokoro current limit, and a current limit control means for controlling said inverter, said predetermined current limit value, wherein the respective electric components It is determined based on the frequency of the AC current value output under average driving conditions within a range not exceeding the allowable value, and is independent of the DC-side current limit between the battery and the inverter. It is provided.

(2) In the control apparatus for an electric vehicle according to the application example, the current limit control unit calculates I ² t which is a current squared time product in a predetermined period corresponding to the electric component as a current value in the power supply circuit. Then, the inverter may be controlled so that the I ² t does not exceed the predetermined current limit value.

  (3) In the control apparatus for an electric vehicle according to this application example, the current limit control unit is a moving average current value that is a moving average of a current value in a predetermined period corresponding to the electrical component as a current value in the power supply circuit. And the inverter may be controlled such that the moving average current value does not exceed the predetermined current limit value.

  (4) In the control apparatus for an electric vehicle according to this application example, the current limit control unit limits the current value in the power supply circuit as the current value in the power supply circuit approaches the predetermined current limit value. The inverter may be controlled so as not to exceed the predetermined current limit value by increasing the ratio.

  (5) In the control apparatus for an electric vehicle according to this application example, the electric component of the power supply circuit may include a cable and a connector for connecting the electric motor and the inverter.

(6) An electric vehicle control method according to this application example includes: an electric motor that is a drive source of the vehicle; a battery that can store electric power for driving the electric motor; and a direct current and an electric current between the battery and the electric motor. An electric vehicle control method comprising: an inverter that converts alternating current; and a circuit that supplies power between the electric motor and the inverter, each having a predetermined thermal load tolerance. current in the power supply circuit consisting of the, the inverter is controlled so as not to exceed the Jo Tokoro current limit value, the predetermined current limit, to the extent that the does not exceed the allowable value of the electrical components, the average It is determined based on the frequency of the alternating current value output under typical driving conditions, and is provided independently of the direct current limit between the battery and the inverter .

(7) In the method for controlling an electric vehicle according to this application example, I ² t, which is a current square time product in a predetermined period corresponding to the electric component, is calculated as a current value in the power supply circuit, and the I ² t is The inverter may be controlled so as not to exceed the predetermined current limit value.

  (8) In the method for controlling an electric vehicle according to this application example, a moving average current value that is a moving average in a predetermined period corresponding to the electric component is calculated as a current value in the power supply circuit, and the moving average current value is The inverter may be controlled so as not to exceed the predetermined current limit value.

  (9) In the method for controlling an electric vehicle according to this application example, the ratio of limiting the current value is increased as the current value in the power supply circuit approaches the predetermined current limit value. The inverter may be controlled so as not to exceed the limit value.

  According to the present invention using the above means, it is possible to optimize the specifications of the electric components in the electric drive device, to reduce the size and cost of the electric drive device, and to examine the usage conditions of the electric components in the design stage. Simplification can be made and the examination accuracy can be improved.

It is a schematic block diagram of the electric vehicle provided with the control apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the electric drive device of FIG. It is a graph which shows the relationship between the allowable heat load of each electric component, and a current limiting value line. It is explanatory drawing which shows output distribution of the electric current effective value IM between a motor and an inverter when drive | working on average driving | running conditions. It is a flowchart which shows the electric current limiting control routine which inverter ECU of the control apparatus which concerns on one Embodiment of this invention performs. FIG. 6 is a relationship diagram between I ² t and an output limit value.

  An example of an embodiment to which the present invention is applied will be described below with reference to the drawings. However, the present invention is not limited only to the following embodiments. The present invention includes any combination of the following embodiments and modifications thereof.

  FIG. 1 is a schematic configuration diagram of a control device for an electric vehicle according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the electric drive device of FIG. 1, which will be described below with reference to these drawings. .

  The electric vehicle 1 in the present embodiment shown in FIG. 1 is a so-called parallel type hybrid truck that uses an engine 2 and a motor 3 (electric motor) as travel driving sources, and is simply referred to as a vehicle in the following description.

  A clutch 4 is connected to the output shaft of the engine 2, and an input side of the transmission 5 is connected to the clutch 4 via a rotating shaft of the motor 3. A differential device 7 is connected to the output side of the transmission 5 via a propeller shaft 6, and left and right drive wheels 9 are connected to the differential device 7 via a drive shaft 8.

  The motor 3 is connected to a battery 11 capable of storing electric power for driving the motor 3 via an inverter 10 that converts direct current and alternating current. The motor 3 is mainly composed of the motor 3, the inverter 10, and the battery 11. An electric drive device is configured.

  The vehicle 1 configured as described above travels by the driving force generated by the engine 2 or the motor 3 being shifted by the transmission 5 and then transmitted to the driving wheels 9. For example, when the vehicle 1 decelerates or travels on a downhill road, the motor 3 operates as a generator by reverse driving from the drive wheel 9 side. The negative driving force generated by the motor 3 is transmitted to the driving wheel 9 side as a braking force, and the AC power generated by the motor 3 is converted into DC power by the inverter 10 and charged to the battery 11.

  As the electric drive device, a known AC motor such as a synchronous motor or an induction motor can be used. In the present embodiment, an example in which a three-phase AC motor is applied to the motor 3 will be described as an example. Specifically, as shown in FIG. 2, the motor 3 includes a rotor on which a permanent magnet is attached and a stator on which a three-phase coil including a U-phase coil U, a V-phase coil V, and a W-phase coil W is wound. It is the synchronous generator motor provided.

  The inverter 10 corresponds to the three-phase coil of the motor 3 and has a pair of switching elements (semiconductor elements) 12a to 12f (for example, IGBT: insulated gate bipolar transistor) per phase. In the switching elements 12a to 12f, a pair of switching elements (12a and 12d, 12b and 12e, and 12c and 12f) are arranged in series, and are connected in parallel to other sets of switching elements. The inverter 10 is a power converter in which a three-phase bridge circuit composed of these switching elements 12a to 12f and a capacitor 13 for smoothing voltage fluctuation are arranged in parallel. Conversion with alternating current is performed to control the current of the supplied power.

  The AC side of the inverter 10 is connected to the motor 3 via a cable 14 including three-phase electric wires 14a, 14b, and 14c. The cable 14 is connected to the motor-side connector 15 at the connection portion on the motor 3 side, and to the inverter-side connector 16 at the connection portion on the inverter 10 side. A power supply circuit for supplying power between the motor 3 and the inverter 10 is formed by electrical components such as the cable 14, the motor-side connector 15, and the inverter-side connector 16.

For these electrical components, an allowable value (upper limit value) of the thermal load based on the current and thermal characteristics of the electrical component is determined. A known calculation method can be applied to the calorific value (thermal load) when the electrical component is conducting. For example, I ² t (current square time product), which is a time product of the square of current and energization time, It is obtained from IRMS which is a root mean square or a moving average current value which is a moving average of current values.

In the following embodiment, an example in which I ² t is applied will be described as an example. However, the present invention is not limited to this, and a root mean square of a current, a moving average current value, or the like may be applied.

  In addition, a harness which is an assembly part of a cable and a connector is also included as an electric part constituting the power supply circuit. Therefore, the allowable value of the thermal load of the electrical component may correspond to the harness that is an assembly.

  On the other hand, the DC side of the inverter 10 is connected to the battery 11 via the relay unit 17. The relay unit 17 includes a positive side relay 17a that connects and disconnects the positive side of the inverter 10 and the battery 11, and a negative side relay 17b that connects and disconnects the negative side.

  The battery 11 is, for example, a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The position of the fuse 19 is not particularly limited, and may be provided between the cells 18, for example.

  In addition, an inverter ECU 20 that is connected to the inverter 10 and controls the inverter 10 is mounted on the vehicle 1. In addition to the inverter 10, the inverter ECU 20 is connected to the motor 3, various devices (not shown), and other ECUs, and information such as the state of the battery 11 and the required output of the motor 3 is input. The inverter ECU 20 controls the inverter 10 according to the state of the battery 11 and the motor 3, the required output, and the like via a drive circuit that turns on and off the switching elements 12a to 12f of the inverter 10.

  Inverter ECU 20 is connected to current sensors 21 a, 21 b, 21 c provided corresponding to each phase of motor 3 in inverter 10, and inverter ECU 20 is connected to AC between inverter 10 and motor 3. Detect current. Specifically, the inverter ECU 20 detects the current of each phase from each of the current sensors 21a, 21b, 21c at a predetermined cycle, and calculates the effective current value I between the inverter 10 and the motor 3 from the current of each phase. Remember.

  Further, the inverter ECU 20 has a predetermined current limit value L determined so as not to exceed the allowable value (upper limit value) of the thermal load in each electrical component of the cable 14, the motor-side connector 15, and the inverter-side connector 16. It is remembered.

Specifically, referring to FIG. 3, the horizontal axis represents the integration time, the vertical axis represents I ² t between the inverter 10 and the motor 3, and the relationship between the allowable value of the thermal load of each electrical component and the current limit value line. The graph which shows is shown.

As shown in FIG. 3, the predetermined current limit value L determined in the inverter ECU 20 can be expressed as a current limit value line K _L that decreases with time, and the allowable value K1 of the cable 14, the motor-side connector 15. tolerance K2, and the allowable value K3 of the inverter-side connector 16 becomes a value higher than both the current limit line K _L of.

The current limit value line K _L is based on the frequency of the effective current value I output from the inverter 10 to the motor 3 under the average driving condition of the vehicle 1 and does not exceed the permissible values K1, K2, and K3 of each electrical component. Stipulated in Specifically, as shown in FIG. 4, the output distribution of the effective current value IM between the motor 3 and the inverter 10 when the vehicle 1 travels under a predetermined average traveling condition is measured, and the most frequent high IMave to, for example, the maximum value of the current that would be used in a practical range (IMup) can be set to the current limit value line K _L. For example, it may be set the maximum value IMup in the range of 4σ power distribution of the current effective value IM to the current limit value line K _L.

By setting such a current limit line K _L, in the design stage of the vehicle 1, the cable 14, as electrical components on the AC side, such as a motor-side connector 15 and the inverter-side connector 16, tolerance the current limit value greater than the line K _L, and by selecting the electrical components close to the current limit value line K _L, it is possible to select a proper specifications electrical components that is neither too specification.

Inverter ECU20 performs current limiting control as actual AC current does not exceed the current limit line K _L.

Specifically, the inverter ECU ²⁰ calculates an integrated value (current squared time product (I ² t) Iax) of the square of the current effective value I in one or more predetermined periods (tx, ty, tz. , Iay, Iaz,...). These predetermined periods are set according to the current and temperature characteristics of the electrical components on the AC side of the cable 14, the motor-side connector 15, and the inverter-side connector 16. In the present embodiment, as an example of the predetermined period, as illustrated in FIG. 3, it is described that three periods of a short period (tx), a middle period (ty), and a long period (tz) are set. The number of predetermined periods is appropriately determined depending on the configuration of the electrical component.

Inverter ECU20 further current limit value for each period from the current limit line _{K L (Lx, Ly, Lz} ) is calculated. Then, I ² t (Iax, Iay, Iaz) in each period is compared with the current limit values (Lx, Ly, Lz), and the I ² t (Iax, Iay, Iaz) is compared with the current limit values (Lx, Ly). , Lz) is approaching or exceeded, the inverter 10 limits the alternating current so as not to exceed the allowable value of each electrical component (current limiting control means).

  Here, FIG. 5 shows a current limit control routine executed by the inverter ECU 20 in a flowchart, and the current limit control of the inverter 10 performed by the inverter ECU 20 will be described in more detail along the flowchart.

First, as step S1, the inverter ECU 20 calculates an integral value of the current effective value I for each of the three periods, ie, the short period (tx), the middle period (ty), and the long period (tz) up to the present time. Specifically, the inverter ECU 20 determines the current value (I ₁ : current current value, I I) at each time point from the stored current effective value log with the sampling number (x, y, z) corresponding to each period. ₂ : Current values acquired in the previous calculation cycle from the present,... Ix,... Iy,. Then, Iax, Iay, and Iaz, which are I ² t in each period, are calculated based on Equation 1 below. ts is a software calculation cycle.

In step S2, as shown in the following formula 2, any of I ² t (Iax, Iay, Iaz) calculated in step S2 is set to a current limit value (Lx, Ly, Lz) corresponding to each period. It is determined whether or not the value is greater than a value multiplied by a predetermined ratio (α _x , α _y , α _z ). A value obtained by multiplying the current limit values (Lx, Ly, Lz) by a predetermined ratio is a threshold value for starting current limit (hereinafter referred to as a current limit start threshold value). All the predetermined ratios are set to 0.8.
(Equation 2)
Iax> Lx × 0.8
Iay> Ly × 0.8
Iaz> Lz × 0.8

If the condition expressed by Equation 2 in step S2 is not satisfied, that is, if any of I ² t (Iax, Iay, Iaz) in each period is equal to or less than the current limit start threshold value, the process proceeds to step S3.

  In step S3, the inverter ECU 20 controls the current of the inverter 10 so that the motor output Wout becomes the required output Wr without limiting the current, and the routine ends.

On the other hand, when the condition expressed by Equation 2 in Step S2 is satisfied, that is, when any of I ² t (Iax, Iay, Iaz) in each period exceeds the current limit start threshold, the determination is made. The result is true (Yes), and the process proceeds to step S4.

In step S4, as shown in Equation 3 below, output limit values (Dx, Dy, Dz) corresponding to each period are calculated. The output limit values (Dx, Dy, Dz) are dimensionless quantities from 0 to 1, and the closer to the current limit values (Lx, Ly, Lz), the closer to 0, I ² t (Iax, Iay, Iaz). The closer to the current limit start threshold, the closer to 1. Specifically, as shown in FIG. 6, based on the following Equation 3, for example, when the current limit start threshold is 0.8 × Lx, if Iax = 1.0Lx, Dx = 0 and Iax = 0 .9Lx, Dx = 0.5, and if Iax ≦ 0.8Lx, Dx = 1. As I ² t (Iax, Iay, Iaz) approaches the current limit value (Lx, Ly, Lz), The ratio that limits the current value increases.

  In the subsequent step S5, the inverter ECU 20 selects the minimum output limit value (hereinafter referred to as the minimum output limit value Dmin) among the output limit values (Dx, Dy, Dz) calculated in accordance with each period in the step S4. .

  Further, in step S6, the inverter ECU 20 indicates that the required output Wr to the motor 3 is the maximum output value of the system at the motor rotational speed at this time (for example, the maximum output current of the inverter 10, the maximum output torque of the motor 3, etc.). Here, it is determined whether or not it is larger than the value obtained by multiplying Wmax by the minimum output limit value Dmin.

  If the determination result is false (No), that is, if the required output Wr is less than or equal to the limited motor output (Wmax × Dmin), the process proceeds to step S3 described above. In step S3, as described above, the inverter ECU 20 controls the current of the inverter 10 so that the motor output Wout becomes the required output Wr without limiting the current, and the routine ends.

  On the other hand, if the determination result in step S6 is true (Yes), that is, if the required output Wr is greater than the limited motor output (Wmax × Dmin), the process proceeds to step S7.

  In step S7, the inverter ECU 20 limits the AC current of the inverter 10 so that the motor output Wout becomes a value obtained by multiplying the maximum motor output Wmax by the minimum output limit value Dmin, and ends the routine. That is, in step S7, when the current of the inverter 10 is controlled so that the motor output Wout becomes the required output Wr as in step S3, the alternating current from the inverter 10 to the motor 3 becomes the current limit value (Lx, Ly, Lz). Therefore, the output of the alternating current is limited so that the motor output Wout is limited by the minimum output limit value Dmin.

  The control device and control method for an electric vehicle according to the present embodiment have the following features, for example.

  As described above, in the control device and the control method including only the DC current limitation between the battery and the inverter as disclosed in Patent Document 1, the specifications of the electrical components in the recent electric vehicle aiming at high output of the motor It is practically difficult to optimize the above, and as a result, excessive specification of electrical components on the AC current side is caused.

  However, according to the control device and the control method according to the present embodiment, the inverter ECU 20 is determined based on the frequency of the current value output under average traveling conditions in a range not exceeding the allowable value of each electric component. By setting the predetermined current limit value L, it is possible to select an AC component on the AC side based on the current limit value L. In particular, by selecting an electrical component that is larger than the current limit value L and has an allowable value close to the current limit value L, it is possible to select an appropriately used electrical component that is not over-specification. As a result, unnecessary high-performance components are not used, and a substantial reduction in the size and cost of the electric drive device can be achieved even in an electric vehicle that increases the output of the motor.

  And even if the allowable value is close to the current limit value L, the safety of the electrical component can be ensured by performing the current limit control on the inverter 10 so that the inverter ECU 20 does not exceed the current limit value L.

  Moreover, in the control apparatus and control method for the electric vehicle according to the present embodiment, as described above, the current limit between the inverter 10 and the motor 3 is independent of the DC-side current limit between the battery 11 and the inverter 10. Current limiting on the AC side can be performed. In this manner, when the AC side current limit is provided independently of the DC side current limit in the power supply circuit, for example, the DC side or AC side electrical component of the inverter 10 is changed to an electrical component having a different specification. However, if the allowable value of the electric component on the AC side is larger than the current limit value L, the safety is maintained by the current limit control. In other words, the design process can be remarkably simplified and the examination accuracy can be improved by separating the process for examining the use conditions of the DC-side electrical components from the process for examining the use conditions of the AC-side electrical parts at the design stage. Can be made.

Further, as performed in step S1, I ² t (Iax, Iay, Iaz), which is a current square time product in a predetermined period nearest from the present time, is calculated, and the I ² t is calculated as a current limit value (La, By controlling so that it does not exceed (Ly, Lz), high-accuracy current limit control including changes in alternating current can be realized.

The output limit values (Dx, Dy, Dz) calculated in step S4 are set so as to increase as I ² t (Iax, Iay, Iaz) approaches the current limit values (La, Ly, Lz). Therefore, the current can be gradually limited according to the state of the vehicle 1, and more appropriate current limit control is realized.

  From the above, according to the control device and the control method for an electric vehicle according to the present embodiment, it is possible to optimize the specifications of the electrical components in the electric drive device, and to reduce the size and cost of the electric drive device. It is possible to simplify the examination of the usage conditions of the electrical component in the design stage and improve the examination accuracy.

  Although the description about the embodiment of the control device for an electric vehicle according to the present invention is finished above, the embodiment is not limited to the above embodiment.

  Although the electric vehicle 1 of the above embodiment is a hybrid vehicle using the engine 2 and the motor 3 as drive sources, the present invention can be similarly applied to an electric vehicle and a fuel cell vehicle using only the motor as a drive source.

In the above embodiment, are set to a value corresponding to 4σ from the output distribution of the current effective value IM between the motor 3 and the inverter 10 when the vehicle travels the current limit line K _L in average driving conditions This may be set by other methods such as 3σ.

In the above embodiment, three periods are set as the predetermined period for calculating I ² t. However, the predetermined period is not limited to three. Further, the current limit start threshold is set to the current limit value Lx × 0.8, but the setting of the current limit start threshold is not limited to this, and a ratio other than 0.8 may be set. The predetermined value may be set in advance.

1 Vehicle 2 Engine 3 Motor (electric motor)
DESCRIPTION OF SYMBOLS 10 Inverter 11 Battery 12a-12f Switching element 13 Capacitor 14 Cable 15 Motor side connector 16 Inverter side connector 20 Inverter ECU (current limitation control means)
21a, 21b, 21c Current sensor

Claims (9)

An electric motor that is a drive source of the vehicle and can generate electricity;
A battery capable of storing electric power for driving the electric motor;
An inverter that performs direct current and alternating current conversion between the battery and the electric motor;
A circuit that supplies power between the electric motor and the inverter, and a power supply circuit that includes a plurality of electrical components each having a predetermined thermal load tolerance;
Current value in the power supply circuit, so as not to exceed the Jo Tokoro current limit, and a current limit control means for controlling the inverter,
The predetermined current limit value is determined based on a frequency of an alternating current value output under an average running condition within a range not exceeding the allowable value of each electric component, and the battery and the inverter A control device for an electric vehicle , characterized in that the control device is provided independently of a current limit on a direct current side between the two . The current limiting control means calculates the I ² t is the current squared time product in a predetermined period corresponding to the electrical component as a current value in the power supply circuit, the I ² t exceeds the predetermined current limit value The control device for an electric vehicle according to claim 1, wherein the inverter is controlled so as not to exist.   The current limit control means calculates a moving average current value that is a moving average of current values in a predetermined period corresponding to the electrical component as a current value in the power supply circuit, and the moving average current value is the predetermined current limit. The control device for an electric vehicle according to claim 1, wherein the inverter is controlled so as not to exceed a value.   The current limit control means exceeds the predetermined current limit value by increasing a ratio of limiting the current value in the power supply circuit as the current value in the power supply circuit approaches the predetermined current limit value. The control apparatus of the electric vehicle as described in any one of Claim 1 to 3 which controls the said inverter so that it may not exist.   The electric vehicle control device according to any one of claims 1 to 4, wherein an electric component of the power supply circuit includes a cable and a connector for connecting the electric motor and the inverter. An electric vehicle control method comprising: an electric motor that is a driving source of a vehicle; a battery that can store electric power for driving the electric motor; and an inverter that converts direct current and alternating current between the battery and the electric motor. Because
Current in the power supply circuit comprising a plurality of electrical components with acceptable values of a circuit given heat load for supplying power between the inverter and the electric motor does not exceed Jo Tokoro current limit controlling said inverter so that,
The predetermined current limit value is determined based on a frequency of an alternating current value output under an average running condition within a range not exceeding the allowable value of each electric component, and the battery and the inverter A control method for an electric vehicle , characterized in that the control method is provided independently of a current limit on a direct current side between the motor and the vehicle. As the current value in the power supply circuit, I ² t, which is a current square time product in a predetermined period corresponding to the electrical component, is calculated, and the inverter is controlled so that the I ² t does not exceed the predetermined current limit value The method for controlling an electric vehicle according to claim 6.   A moving average current value that is a moving average in a predetermined period corresponding to the electrical component is calculated as a current value in the power supply circuit, and the inverter is controlled so that the moving average current value does not exceed the predetermined current limit value The method for controlling an electric vehicle according to claim 6.   7. The inverter is controlled so as not to exceed the predetermined current limit value by increasing a ratio of limiting the current value as the current value in the power supply circuit approaches the predetermined current limit value. The control method of the electric vehicle as described in any one of 1-8.

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