JP2016187237A - Driving device for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device for an electric vehicle that can effectively prevent occurrence of a decelerating and diminishing feeling of the vehicle while adjusting appropriately power generated by a motor according to charge amounts of a battery.SOLUTION: At a non-powering time when a battery 2 is in a low charging state, switching means SW1 and SW2 are controlled so that at least regenerative braking force is generated by a first winding wire L1. At a non-powering time when the battery 2 is in a high-charging state, if rotation speed of a motor 1 is less than reference speed, the switching means SW1 and SW2 are controlled so that regenerative braking force is generated by the first winding wire L1 and regenerative braking force is not generated by a second winding wire L2. At the non-powering time when the battery 2 is in the high-charging state, if the rotation speed of the motor 1 is equal to the reference speed or more, the switching means SW1 and SW2 are controlled so that the regenerative braking force is generated by the first winding wire L1 and short-circuit braking force is generated by the second winding wire L2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor capable of driving a wheel during power running and generating electric power during non-power running to generate a braking force, a battery capable of charging electric power generated by the motor, and alternating electric power charged in the battery. The present invention relates to an electric vehicle drive device including an inverter that is supplied to a motor while being converted into electric power, and a control unit that controls the motor and the inverter.

  As a motor used in an electric vehicle, for example, the one in the following Patent Document 1 is known. The motor for an electric vehicle shown in this Patent Document 1 is a so-called three-phase AC synchronous motor, and has a plurality of windings connected in series in each phase (U phase, V phase, W phase). . This motor has switching means composed of a plurality of switches (high-speed winding switch and low-speed winding switch) in order to switch the energization state of each winding. The switching means plays a role of switching the energization state of each winding in accordance with the rotational speed of the motor, for example, when the vehicle is in powering (when the vehicle is traveling by the driving torque generated by the motor). For example, in order to ensure a high torque at a low speed range where the motor rotation speed is low, the switching means is controlled so that current flows through all of the plurality of windings, and at a high speed range where the motor rotation speed is high, induction is induced. In order to suppress the voltage, the switching means is controlled so that a current flows only in a part of the plurality of windings.

JP 2011-50150 A

  Here, as described above, the control for switching the energization state of the winding in accordance with the rotational speed of the motor is performed not only when the vehicle is powering but also when the vehicle is not powering (when the vehicle is coasting or decelerating). Generally done. That is, when the vehicle is not powered, an induced voltage proportional to the rotational speed is generated as the motor is rotated by the wheels. The proportional constant (induced voltage constant) of the induced voltage is changed according to the speed range. Therefore, the winding switching control is performed. Specifically, in the low speed range where the motor rotation speed is low, the current flows through all of the plurality of windings (that is, the induced voltage is generated in all the windings), and the motor rotation speed is high. In the region, in order to make the induced voltage constant smaller than in the low speed region, a state in which current flows only in a part of the plurality of windings (that is, a state in which an induced voltage is generated only in some windings) and Is done. In any of these cases, reverse torque based on the generated induced voltage is generated in the motor, and braking force by the reverse torque is applied to the wheels (so-called regenerative braking force).

  When the vehicle in which the induced voltage is generated as described above is not powered, the battery is charged with the generated power based on the induced voltage, so that the energy can be effectively used. However, when the amount of charge of the battery is already large enough, there is a limit to the power that can be absorbed by the battery, so the power generated by the motor must be suppressed, thereby reducing the regenerative braking force. In this way, when the regenerative braking force is reduced due to the circumstances of the battery, the driver who does not know the battery conditions feels so-called deceleration omission (it feels that the braking force has suddenly decreased), so it is safe from the standpoint of merchantability. It is not preferable in terms of the nature.

  The present invention has been made in view of the circumstances as described above, and while adjusting the generated power by appropriately adjusting the power generated by the motor in accordance with the amount of charge of the battery, it is possible to feel the vehicle slowing down. An object of the present invention is to provide a drive device for an electric vehicle that can effectively prevent the occurrence of the above.

  In order to solve the above-described problems, the present invention provides a motor capable of driving a wheel during power running and generating electric power during non-power running to generate a braking force, and a battery capable of charging electric power generated by the motor. And an inverter for supplying electric power charged in the battery to the motor while converting it into AC power, and a control means for controlling the motor and the inverter, wherein the motor is connected in series. First and second windings, and switching means for switching the energization state of each winding, and the switching means is a state in which current flows through both the first winding and the second winding. And an energized state can be switched between a state in which a current flows only in the first winding and a state in which a current is short-circuited so that a circulating current flows in the second winding. When the rotational speed of the motor is less than a predetermined reference speed during non-powering in a low charge state where the amount is less than a predetermined reference charge amount, the first winding and the second winding The switching means is controlled so as to generate a regenerative braking force by a line, and when the rotation speed is equal to or higher than the reference speed during non-powering when the battery is in the low charge state, at least the first winding When the rotation speed is less than the reference speed during non-powering when the switching means is controlled to generate a regenerative braking force due to and the battery is in a high charge state where the charge amount of the battery is equal to or greater than the reference charge amount Controls the switching means so that the regenerative braking force is generated by the first winding and the regenerative braking force is not generated by the second winding, and the non-switching is performed when the battery is in the high charge state. When the rotation speed is equal to or higher than the reference speed, the switching means is controlled so that a regenerative braking force by the first winding and a short-circuit braking force by the second winding are generated. (Claim 1).

  According to the present invention, when the battery is in a low charge state, the switching means is controlled so that at least the regenerative braking force is generated by the first winding. As a result, the electric power generated by the motor can be charged in a battery having a sufficient free capacity to increase the amount of charge, and a required braking force can be applied from the motor to the wheels.

  On the other hand, when the amount of charge is increased and the battery is in a high charge state, and when the rotational speed of the motor is lower than the reference speed, a regenerative braking force is generated by the first winding and the regenerative braking by the second winding is performed. The switching means is controlled so that no braking force is generated. In this way, when regenerative braking by the second winding is prohibited, compared to when regenerative braking by the first winding and the second winding is performed (when the rotation speed is lower than the reference speed in a low charge state). Therefore, even if the same regenerative braking force is generated, the electric power charged in the battery is reduced. For this reason, an increase in the battery charge amount can be suppressed without greatly reducing the braking force applied from the motor to the wheels.

  Further, when the battery is in a high charge state and the motor rotation speed is equal to or higher than the reference speed, a regenerative braking force by the first winding and a short-circuit braking force by the second winding are generated. The switching means is controlled. Thus, by covering a part of the braking force applied to the wheels with the short-circuit braking force, it is possible to reduce the regenerative braking force and reduce the electric power charged in the battery. That is, the short-circuit braking force is based on the circulating current circulating through the second winding, and since this circulating current does not flow to the battery, even if the short-circuit braking force is generated, the amount of charge of the battery increases accordingly. There is no. On the other hand, although the generated power corresponding to the regenerative braking force is used for charging the battery, the regenerative braking force can be reduced by the presence of the short-circuit braking force, so the power charged to the battery can be reduced. it can. In addition, the net braking force by the motor (the sum of the regenerative braking force and the short-circuit braking force) does not need to be greatly reduced as compared with the case where there is no short-circuit braking force.

  As described above, when the battery is in a high charge state, even if the rotational speed of the motor is less than or equal to the reference speed, the battery is being devised so that the net braking force by the motor does not suddenly decrease. Therefore, it is possible to effectively prevent the vehicle from feeling decelerated as the battery enters a highly charged state.

  In the present invention, it is preferable that the control unit is configured to generate a regenerative braking force by the first winding when the rotational speed is less than the reference speed during non-powering when the battery is in the high charge state. The switching means is controlled so that a short-circuit braking force is generated by the second winding.

  As described above, when both the regenerative braking force and the short-circuit braking force are generated by the same control as when the rotational speed is lower than the reference speed, the electric power charged in the battery The effect of reducing can be further increased.

  In the above configuration, more preferably, the control means reduces the ratio of the regenerative braking force and increases the short-circuit braking force as the charge amount of the battery increases during non-powering when the battery is in the high charge state. Is increased (claim 3).

  In this way, when the ratio of the short-circuit braking force is gradually increased while gradually reducing the ratio of the regenerative braking force, it is possible to charge the battery while reliably preventing a sudden decrease in the braking force that leads to a feeling of slowdown. An increase in the amount can be effectively suppressed.

  In the above configuration, more preferably, the switching means includes a semiconductor element capable of switching a short circuit / non-short circuit of the second winding based on switching ON / OFF, and the control means is based on the second winding. The ratio of the short-circuit braking force is controlled based on the duty ratio of the semiconductor element.

  According to this configuration, the ratio of the regenerative braking force and the short-circuit braking force can be appropriately increased / decreased by adjusting the duty ratio of the semiconductor element while performing switching control (repeat ON / OFF).

  In the present invention, it is preferable that the vehicle includes a brake pedal operated by a driver and a hydraulic brake device that applies a braking force due to friction to the wheel, and the control means corresponds to an operation amount of the brake pedal. And setting the target braking force, and controlling the brake device so that the sum of the braking force by the brake device and the braking force by the motor matches the target braking force.

  According to this configuration, even if the braking force applied from the motor to the wheels is insufficient when the battery is in a high charge state, the shortage can be compensated by the hydraulic brake device. A stable braking force can be applied to the wheel regardless of the state. Further, since the braking force by the brake device can be reduced by the amount of braking force by the motor, the amount of wear on the brake pads can be reduced.

  In the present invention, when the rotational speed is equal to or higher than the reference speed during non-powering when the battery is in the low charge state, a regenerative braking force is generated by the first winding and the second winding The switching means may be controlled so that no regenerative braking force is generated.

  According to this configuration, the braking force of the motor in the high speed range can be appropriately generated using only the first winding.

  Here, the vehicle may be provided with a mode selection switch for switching the traveling mode of the vehicle between the sports mode and the other modes. In this case, when the rotation speed is equal to or higher than the reference speed when the sport mode is selected by the mode selection switch and the battery is in the low charge state and the rotation speed is equal to or higher than the reference speed, the control means It is preferable to control the switching means so that a regenerative braking force is generated by the first winding and the second winding.

  According to this configuration, it is possible to realize a sporty riding taste such that the vehicle decelerates relatively abruptly with the release of the accelerator pedal, for example, in the high speed range of the motor.

  As described above, according to the electric vehicle drive device of the present invention, the vehicle can be decelerated by adjusting the generated power while appropriately adjusting the power generated by the motor in accordance with the amount of charge of the battery. Can be effectively prevented.

1 is a diagram schematically showing a configuration of an electric vehicle to which a drive device according to an embodiment of the present invention is applied. It is a circuit diagram which shows the electric constitution of a motor, a battery, and an inverter. It is a block diagram which shows the control system of a vehicle. It is a flowchart (the 1) which shows the control action in driving | running | working of a vehicle. It is a flowchart (the 2) which shows the control action in driving | running | working of a vehicle. 7 is a flowchart (No. 3) illustrating a control operation during traveling of the vehicle. It is a table | surface which shows ON / OFF according to conditions of the 1st, 2nd switch of a motor. It is a figure for demonstrating the electric current which flows through a motor, (a) is a thing at the time of low speed mode, (b) is a thing at the time of high speed mode. It is a figure for demonstrating the electric current which flows into a motor at the time of regenerative power generation suppression mode. It is a figure for demonstrating the electric current which flows into a motor at the time of regenerative power generation prohibition mode. It is a figure which shows the output characteristic of a motor. It is a time chart which shows the operation example at the time of non-power running of a vehicle. FIG. 8 is a view corresponding to FIG. 7 for describing a modification of the embodiment. FIG. 8 is a view corresponding to FIG. 7 for explaining another modification of the embodiment.

(1) Overall Configuration FIG. 1 is a diagram schematically showing a configuration of an electric vehicle to which a drive device according to an embodiment of the present invention is applied. The vehicle shown in this figure is a so-called electric vehicle driven only by electric energy, and is consumed by an electric motor 1 (hereinafter simply referred to as a motor 1) provided as a driving power source, the motor 1, and the like. A battery 2 for storing electric power, an inverter 3 for supplying DC power stored in the battery 2 to the motor 1 while converting it into AC power, and a controller 4 for controlling the motor 1 and the inverter 3 (control means in claims) Equivalent).

  The motor 1 is linked to a pair of left and right drive shafts 7 via a gear train 5 and a differential device 6, and wheels 8 are coupled to the outer ends of the drive shafts 7. The vehicle of this embodiment is a front wheel drive type. For this reason, the motor 1 is linked and connected to the front two wheels 8 among the four wheels provided on the front, rear, left and right sides of the vehicle. That is, in this embodiment, the two front wheels (front wheels) 8 are drive wheels, and the two rear wheels (rear wheels) 9 are driven wheels.

  The motor 1 is driven by the electric power supplied from the battery 2 to rotate the wheels 8 when the vehicle is running, that is, when the vehicle is running with an accelerator pedal (not shown) provided in the vehicle being depressed. . That is, when the vehicle is powered, the motor 1 is driven by electric power supplied from the battery 2 via the inverter 3, and the driving force of the motor 1 is transmitted via the gear train 5, the differential device 6, and the drive shaft 7. It is transmitted to the wheel 8.

  On the other hand, when the vehicle is not powered, that is, when the vehicle is traveling with the accelerator pedal not depressed (when the vehicle is coasting or decelerating), the drive wheels 8 are rotating by inertia. Then, the motor 1 is rotated by a driving force input from the drive shaft 7 or the like, and an induced voltage is generated in the motor 1 due to the rotation (that is, power generation is performed). The electric power generated by the motor 1 is charged into the battery 2 via the inverter 3.

  The vehicle is provided with a hydraulic (hydraulic pressure) brake device 10 that applies a braking force by friction to the wheels 8 and 9. As shown in FIG. 3 to be described later, the brake device 10 includes a disc brake 11 provided on each of the wheels 8 and 9, a hydraulic pump 12 that supplies hydraulic pressure to the disc brake 11, and an electric type that drives the hydraulic pump 12. Brake motor 13 and a hydraulic solenoid valve 14 for adjusting the hydraulic pressure supplied to the disc brake 11. The disc brake 11 includes a rotor that rotates integrally with the wheels 8 and 9 and a brake pad that sandwiches the rotor (both not shown). The brake pad receives the supply of hydraulic pressure from the hydraulic pump 12 and receives the rotor. By being pressed against each other, friction is generated between the two and braking force is applied to the wheels 8 and 9. At this time, the hydraulic pressure for pressing the rotor is adjusted by the solenoid valve 14 so that a required braking force is obtained for the wheels 8 and 9.

  FIG. 2 is a circuit diagram showing an electrical configuration of the motor 1, the battery 2, and the inverter 3. As shown in the figure, the motor 1 is a so-called three-phase AC synchronous motor, and each phase (U phase, V phase, W phase) of the motor 1 includes a first winding L1 connected in series and A second winding L2 is provided. Further, in the motor 1, as a switching means for switching the path of the current flowing through the first and second windings L1, L2 of each phase (energization state of each winding), for example, an IGBT (insulated gate bipolar transistor) or the like A first switch SW1 and a second switch SW2 made of semiconductor elements are provided for each phase. The first switch SW1 is provided so that the connection connecting the first windings L1 can be cut off, and the second switch SW2 is provided so that the connection connecting the second windings L2 can be cut off. Yes. In FIG. 2, for ease of understanding, the switches SW1 and SW2 are illustrated as if they exist inside the motor 1, but the switches SW1 and SW2 are equivalent to the circuit diagram of FIG. Any device that exhibits a function may be used, and the motor 1 may be provided either inside or outside.

  The inverter 3 has a plurality of switching elements SW made of semiconductor elements for each phase (U phase, V phase, W phase). During power running of the vehicle, the inverter 3 performs pulse width control on the switching element SW, thereby converting the DC power stored in the battery 2 into AC power having an arbitrary voltage (current) and then supplying the AC power to the motor 1. On the other hand, when the vehicle is not powered, the inverter 3 charges the battery 2 after converting the AC power generated by the motor 1 into DC power having an arbitrary current by the pulse width control of the switching element SW.

  The controller 4 is composed of a microcomputer including a well-known CPU, RAM, ROM and the like, and comprehensively controls each part of the vehicle based on the running state of the vehicle specified by sensors (SN1 to SN5) described later. It has a function.

(2) Control System FIG. 3 is a block diagram showing the control system of the vehicle according to this embodiment. As shown in the figure, the controller 4 is electrically connected to various sensors provided in the vehicle. That is, the vehicle includes an accelerator sensor SN1 that detects an operation amount of an unillustrated accelerator pedal that is depressed by the driver, and a brake sensor that also detects an operation amount of an unillustrated brake pedal that is depressed by the driver. SN2, a vehicle speed sensor SN3 that detects the traveling speed (vehicle speed) of the vehicle, a motor rotation speed sensor SN4 that detects the rotation speed of the output shaft of the motor 1, and a battery sensor SN5 that detects the voltage across the terminals of the battery 2. The various detection values by these sensors SN1 to SN5 are input to the controller 4 as electric signals.

  The controller 4 controls each part of the vehicle while executing various determinations and calculations based on the input signals from the sensors SN1 to SN5. That is, the controller 4 is electrically connected to the first and second switches SW1 and SW2 of the motor 1, the switching element SW of the inverter 3, the brake motor 13, the hydraulic solenoid valve 14, and the like. Based on the results and the like, drive control signals are output to these devices.

  For example, the controller 4 sequentially determines the running state of the vehicle and the charged state of the battery 2 based on the input signals from the sensors SN1 to SN5, and an appropriate output or power generation amount based on the determined state is obtained. In addition, the motor 1 (switches SW1 and SW2) and the inverter 3 (switching element SW) are controlled, and the brake device 10 (hydraulic solenoid valve 14) is controlled so as to obtain a necessary braking force.

(3) Control Operation Next, a control operation executed by the controller 4 while the vehicle is traveling will be described with reference to FIGS. 4 to 6 are flowcharts showing the procedure of the control operation, and FIG. 7 shows how the first and second switches SW1 and SW2 are turned on and off for each condition as a result of the control based on the flowchart. It is the table | surface which showed whether it switches.

  When the control shown in FIG. 4 starts, the controller 4 reads various sensor values (step S1). That is, the controller 4 reads the detected values from the accelerator sensor SN1, the brake sensor SN2, the vehicle speed sensor SN3, the motor rotation speed sensor SN4, and the battery sensor SN5, and based on the read detection values, the accelerator opening degree, the brake operation Various information such as the amount, the vehicle speed, the rotation speed of the motor 1 and the voltage of the battery 2 is acquired.

  Next, the controller 4 determines whether or not the accelerator pedal is depressed based on the detection value of the accelerator sensor SN1 (step S2).

  If it is determined YES in step S2 and it is confirmed that the accelerator pedal is depressed, that is, if it is confirmed that the vehicle is powering, the controller 4 sets the detected value of the motor rotation speed sensor SN4. Based on this, it is determined whether or not the rotational speed of the motor 1 is less than a predetermined reference speed Nx (step S3).

  When it is determined YES in step S3 and it is confirmed that the rotational speed of the motor 1 is less than the reference speed Nx, the controller 4 turns on the first switch SW1 of the motor 1 as shown in FIG. While turning off, the second switch SW2 of the motor 1 is turned on (step S4). In FIG. 8A, a portion where current flows is indicated by a thick line. As shown in the figure, when the first switch SW1 is turned off and the second switch SW2 is turned on, in the motor 1, the current supplied from the inverter 3 is supplied to both the first winding L1 and the second winding L2. Washed away.

  The state shown in FIG. 8A where the first switch SW1 is OFF and the second switch SW2 is ON is hereinafter referred to as a low speed mode. In this low speed mode, since current flows through both the first winding L1 and the second winding L2, the induced voltage constant of the motor 1 is large, and the torque that can be generated is large. On the other hand, when the rotational speed of the motor 1 is increased to some extent, the induced voltage of the motor 1 becomes almost the same as the voltage of the inverter 3, so that the operable speed range is limited to a relatively low speed region. This is why the low speed mode is selected in the region below the reference speed Nx.

  On the other hand, when it is determined NO in step S3 and it is confirmed that the rotational speed of the motor 1 is equal to or higher than the reference speed Nx, the controller 4 performs the first switch of the motor 1 as shown in FIG. The switch SW1 is turned on and the second switch SW2 of the motor 1 is turned off (step S5). As shown in this figure, when the first switch SW1 is turned on and the second switch SW2 is turned off, in the motor 1, the current supplied from the inverter 3 flows only in the first winding L1, and the second winding It does not flow to L2.

  The state shown in FIG. 8B in which the first switch SW1 is turned on and the second switch SW2 is turned off is hereinafter referred to as a high speed mode. In this high-speed mode, current flows only through the first winding L1, and no current flows through the second winding L2, so that the induced voltage constant of the motor 1 is small and the torque that can be generated is small. On the other hand, since the induced voltage of the motor 1 does not reach the voltage of the inverter 3 even when the rotational speed of the motor 1 becomes considerably high, the motor 1 can be rotated to a higher speed side than in the low speed mode. . This is the reason why the high-speed mode is selected in the region of the reference speed Nx or higher.

  FIG. 11 is a characteristic diagram combining the output characteristics of the motor in the low speed mode and the output characteristics of the motor in the high speed mode. As shown in this figure, the low speed mode is selected below the reference speed Nx, and the high speed mode is selected above the reference speed Nx, so that the motor 1 can be operated over a wider speed range. It is possible to output a sufficiently large torque.

  In the above-described control (steps S3 to S5) in which the output characteristics of the motor 1 are switched according to whether the rotational speed detected by the motor rotational speed sensor SN4 is greater than or less than the reference speed Nx, the rotational speed is close to the reference speed Nx. In order to prevent a situation (so-called hunting) in which the output characteristics are frequently switched from the low speed mode to the high speed mode or vice versa, hysteresis specification is given to the reference speed Nx.

  When the operation mode (low speed mode or high speed mode) of the motor 1 to be selected is determined as described above, the controller 4 determines the determined operation mode and the accelerator opening detected by the accelerator sensor SN1. Based on this, the required torque of the motor 1 is calculated (step S6). Then, the electric power (voltage and current) supplied from the inverter 3 to the motor 1 is controlled so that the calculated required torque is generated in the motor 1 (step S7).

  Next, FIG. 5 and FIG. 5 illustrate the control operation when it is determined NO in Step S2, that is, when the vehicle is traveling with the accelerator pedal not depressed (when the vehicle is in a nonpowering state). 6 will be described. In this case, the controller 4 calculates the amount of power charged in the battery 2, that is, the amount of charge SOC of the battery 2 based on the detection value (battery voltage) of the battery sensor SN5 (step S11).

  Next, the controller 4 determines whether or not the calculated charge amount SOC is less than a predetermined first threshold value X1 (step S12). The first threshold value X1 is a value corresponding to the “reference charge amount” in the claims, and is set to a value that is somewhat smaller than the maximum charge amount when the battery 2 is fully charged. That the charge amount SOC of the battery 2 is smaller than the first threshold value X1 means that the battery 2 has a sufficiently large free capacity. A state where the charge amount SOC is smaller than the first threshold value X1 is hereinafter referred to as a low charge state.

  When it is determined YES in step S12 and it is confirmed that the battery 2 is in a low charge state (SOC <X1), the controller 4 determines that the rotation speed of the motor 1 detected by the motor rotation speed sensor SN4 is the same as that described above. It is determined whether the speed is less than the reference speed Nx (step S13).

  When it is determined as YES in step S13 and it is confirmed that the rotation speed is less than the reference speed Nx, the controller 4 turns off the first switch SW1 of the motor 1 as shown in FIG. 2 The switch SW2 is turned on (step S14). That is, the low speed mode is selected as the operation mode of the motor 1.

  When the low speed mode is selected during vehicle non-power running as in step S14, an induced voltage is generated in both the first winding L1 and the second winding L2, and the current based on the induced voltage is converted to the inverter 3 The battery 2 is charged via That is, so-called regenerative power generation using the first winding L1 and the second winding L2 is performed. Further, with such regenerative power generation, a reverse torque based on the induced voltage is generated in the motor 1, and a braking force by the reverse torque is applied to the wheels 8. Hereinafter, braking the wheel 8 with the reverse torque based on such regenerative power generation is referred to as regenerative braking, and the braking force generated by the regenerative braking is referred to as regenerative braking force. The regenerative braking force can be increased or decreased within a predetermined range by controlling the current flowing through the winding by the inverter 3.

  On the other hand, if it is determined as NO in step S13 and it is confirmed that the rotation speed is equal to or higher than the reference speed Nx, the controller 4 turns on the first switch SW1 as shown in FIG. The switch SW2 is turned off (step S15). That is, the high speed mode is selected as the operation mode of the motor 1.

  When the high-speed mode is selected during vehicle non-powering as in step S15, an induced voltage is generated only in the first winding L1, and a current based on the induced voltage is charged to the battery 2 via the inverter 3. Is done. That is, regenerative power generation using only the first winding L1 is performed. Further, with such regenerative power generation, reverse torque based on the induced voltage is generated in the motor 1, and braking force (regenerative braking force) due to the reverse torque is applied to the wheels 8.

  Next, the control operation when it is determined as NO in step S12, that is, when the charge amount SOC of the battery 2 is equal to or greater than the first threshold value X1 will be described. In this case, the controller 4 determines whether or not the charge amount SOC is less than the second threshold value X2 (step S16). The second threshold value X2 is a value larger than the first threshold value X1 and is set to substantially the same value as the maximum charge amount of the battery 2. Here, the maximum charge amount is the maximum charge amount determined by various restrictions during use of the battery 2 (during vehicle travel), that is, the maximum charge amount during use, and the physical maximum charge of the battery 2. Doesn't mean quantity. When the physical maximum charge amount is 100%, the maximum charge amount during use is set to about 70%, for example.

  That the charge amount SOC is equal to or greater than the first threshold value X1 and less than the second threshold value X2 means that the battery 2 is not yet in a fully charged state (a state where the charge amount SOC has almost reached the maximum charge amount). This means that there is a limit to the amount that can be charged. The state where the charge amount SOC is X1 or more and less than X2 is hereinafter referred to as a high charge state.

  When it is determined YES in step S16 and it is confirmed that the battery 2 is in a high charge state (X1 ≦ SOC <X2), the controller 4 turns on the first switch SW1 of the motor 1 and turns on the switch. Switching control that repeatedly turns ON / OFF is executed for the second switch SW2 (step S17). At this time, the duty ratio in the switching control of the second switch SW2, that is, the ratio of the period during which the second switch SW2 is turned on within a certain period is proportional to the charge amount SOC of the battery 2 in the range of 0 to 100%. And set to increase. That is, the smaller the charge amount SOC (closer to the first threshold value X1), the smaller the duty ratio (closer to 0%), and the larger the charge amount SOC (closer to the second threshold value X2), the greater the duty ratio (to 100%). Be near). Hereinafter, the state in which the control in step S17 is performed is referred to as a regenerative power generation suppression mode.

  In the regenerative power generation suppression mode, both the first switch SW1 and the second switch SW2 are turned on during the period when the second switch SW2 is turned on by the switching control, and as shown in FIG. A closed circuit is formed by connecting the second windings L2 (that is, the second winding L2 is short-circuited). Then, a current based on the induced voltage in the second winding L2 circulates in the second winding L2, so that a circulating current Ic as shown in the figure is generated and a reverse torque is generated in the motor 1, and the reverse A braking force by torque is applied to the wheels 8. Hereinafter, braking the wheel 8 with the reverse torque based on the circulating current Ic is referred to as short-circuit braking, and the braking force by the short-circuit braking is referred to as short-circuit braking force. The short-circuit braking plays a role of braking the wheel 8 as in the case of the regenerative braking described above. However, unlike the regenerative braking, the generated current Ic only circulates through the second winding L2, and the battery 2 Not charged for charging.

  On the other hand, in the regenerative power generation suppression mode, since the first switch SW1 is always ON, regenerative power generation by the first winding L1 is continuously performed. That is, as shown in FIG. 9, the regenerative current Ig generated based on the induced voltage in the first winding L1 is charged to the battery 2 via the inverter 3, and the regenerative braking force based on the regenerative power generation is applied to the wheel 8 as shown in FIG. To be granted. However, in the regenerative power generation suppression mode in which the charging power to the battery 2 needs to be suppressed, a value that the regenerative current Ig flowing through the first winding L1 can be generated under the control of the inverter 3 (the charging power to the battery 2 is limited). If it is not done, it will be smaller than the possible value). For example, assuming that the regenerative current Ig that can be generated when there is no restriction on the charging power is 10, the regenerative current Ig is reduced from 10 to 0 as the charge amount SOC of the battery 2 increases (the excess with respect to the threshold value X1 increases). It is gradually made smaller toward. Then, since the regenerative braking force also decreases in proportion to this, it becomes impossible to generate the braking force to be applied from the motor 1 to the wheel 8 with only the regenerative braking force. Therefore, the second switch SW2 is subjected to switching control so as to generate a short-circuit braking force having a magnitude corresponding to the decrease in the regenerative braking force. At this time, since the amount of decrease in the regenerative braking force increases as the charge amount SOC increases, it is necessary to gradually increase the short-circuit braking force accordingly (that is, it is necessary to increase the period during which the second switch SW2 is turned on. ). Under such circumstances, in step S17, the first switch SW1 is always turned on and the second switch SW2 is controlled to be gradually increased in duty ratio.

  In the control of step S17 (regenerative power generation suppression mode), such short-circuit braking and regenerative braking are used in combination, whereby the power required for charging the battery 2 is reduced and the increase in the charge amount SOC is suppressed.

  Next, a description will be given of the control operation when it is determined NO in step S16, that is, when the battery 2 is in a fully charged state where the charge amount SOC of the battery 2 is equal to or greater than the second threshold value X2. In this case, the controller 4 stops the inverter 3 and turns on both the first switch SW1 and the second switch SW2 of the motor 1 (step S18). That is, as shown in FIG. 10, a closed circuit in which the second winding L2 is short-circuited is formed so that the circulating current Ic flows through the second winding L2, and the braking force (short-circuit braking force) based on the circulating current Ic is applied to the wheel. 8 is given. On the other hand, since the inverter 3 is stopped, no regenerative current is generated in the first winding L1. As a result, the current (charge current) flowing through the battery 2 disappears, and as a result, the charge amount SOC of the battery 2 does not increase any more. Hereinafter, the state in which the control in step S18 is performed is referred to as a regenerative power generation prohibition mode.

  Note that the short-circuit braking force of the motor 1 generated in the regenerative power generation prohibition mode can be increased or decreased within a predetermined range by switching the second switch SW2 while the first switch SW1 is always ON. That is, both the first switch SW1 and the second switch SW2 are turned on so that the circulating current Ic flows, and the second switch SW2 is turned off while turning on the first switch SW1 so that the circulating current Ic does not flow. The short-circuit braking force of the motor 1 is increased / decreased by duty controlling the period of the former state (SW1 and SW2 are ON) occupying a certain period alternately.

  As shown in the flowchart of FIG. 5 above, when the vehicle is not powered, the low speed mode or the high speed mode (step S14 or S15), the regenerative power generation suppression mode (step 17), depending on the charge amount SOC of the battery 2; One of the regenerative power generation prohibition modes (step S18) is selected. Regardless of which of these modes is selected, the braking force (regenerative braking force or short-circuit braking force) is applied from the motor 1 to the wheel 8. Generally, the maximum value of the short-circuit braking force is greater than the maximum value of the regenerative braking force. Therefore, the braking force that can be generated decreases in the order of low speed mode and high speed mode → regenerative power generation suppression mode → regenerative power generation prohibition mode. In other words, the braking force that can be generated in the low speed mode and the high speed mode is the largest (in particular, the largest in the low speed mode that uses two windings), and the braking force that can be generated in the regenerative power generation prohibition mode is the smallest. . When the braking force is insufficient in the regenerative power generation suppression mode or the regenerative power generation prohibition mode, the shortage is compensated by the brake device 10 as described later.

  After the operation mode selection of the motor 1 as described above is performed, the controller 4 proceeds to step S21 in FIG. In step S21, a target total braking force, which is a target braking force to be applied to the vehicle, is calculated based on the operation amount of the brake pedal detected by the brake sensor SN2.

  Next, the controller 4 calculates a target motor braking force, which is a target braking force to be generated by the motor 1, based on the target total braking force calculated in step S21 and the operation mode of the selected motor 1. (Step S22). At this time, in order not to use the brake device 10 as much as possible, the maximum target motor braking force (which is the same as or as close as possible to the target total braking force) is set within a range not exceeding the target total braking force.

  Next, the controller 4 calculates a value obtained by subtracting the target motor braking force from the target total braking force as an insufficient braking force (step S23).

  Next, the controller 4 controls the inverter 3 or the first and second switches SW1 and SW2 so that the braking force that matches the target motor braking force is applied from the motor 1 to the wheel 8 (step S24). For example, when the low speed mode or the high speed mode for generating only the regenerative braking force is selected, the braking current of the motor 1 is adjusted by controlling the regenerative current flowing through the winding of the motor 1 using the inverter 3. can do. When the regenerative power generation suppression mode for generating both the regenerative braking force and the short-circuit braking force is selected, the regenerative current (Ig in FIG. 9) flowing through the first winding L1 is controlled by the inverter 3, and the first The braking force of the motor 1 can be adjusted by increasing or decreasing the ratio of the period during which the circulating current (Ic in FIG. 9) flows through the two windings L2 by switching of the second switch SW2. When the regenerative power generation prohibition mode that generates only the short-circuit braking force is selected, the braking force of the motor 1 is controlled by switching the second switch SW2 while the inverter 3 is stopped (the first switch SW1 is ON). Can be adjusted.

  Further, the controller 4 controls the brake device 10 so that the braking force that matches the insufficient braking force is applied from the disc brake 11 to the wheels 8 and 9 (step S25). In this way, the motor 1 and the brake device 10 cooperate to apply a braking force that matches the target total braking force to the vehicle.

(4) Example of Operation Next, an example of operation when the vehicle is not in powering will be described with reference to the time chart of FIG. As a premise of this explanation, it is initially assumed that the operation mode of the motor 1 is the low speed mode. Then, the non-power running of the vehicle is continued for a relatively long time from the initial state in which the low speed mode is selected. Such a traveling pattern can occur, for example, when the vehicle is traveling downhill continuously from a high altitude.

  Before the time t1 shown in FIG. 12, the battery 2 is in a low charge state in which the charge amount SOC is less than the first threshold value X1 (see graph (e)), and the motor 1 has the first switch SW1 OFF. The second switch SW2 is in the low speed mode (see graphs (c) and (d)). Thereby, since electric power generation is performed in a state where current flows through both the first winding L1 and the second winding L2, the battery 2 is charged with considerably large power as shown in the graph (f). For this reason, as shown in the graph (e), the charge amount SOC of the battery 2 increases at a relatively steep pace with time. At time t1, the charge amount SOC reaches the first threshold value X1 (that is, the battery 2 shifts to a high charge state).

  At time t1 when SOC ≧ X1, the motor 1 shifts to the regenerative power generation suppression mode. That is, the first switch SW1 is switched from OFF to ON, and the second switch SW2 is switched from ON to a switching control state (a state in which ON / OFF is repeated) (see graphs (c) and (d)). Since the duty ratio in the switching control of the second switch SW2 is increased as the amount of increase in the charge amount SOC from the first threshold value X1 increases, as shown in the graph (d), the duty ratio is first (at the switching time t1). The duty ratio is almost 0%. Since the duty ratio = 0% is the same as when the second switch SW2 is OFF, the motor 1 at this time is substantially the same as being operated in the high speed mode. For this reason, if the currents flowing through the motor 1 are kept the same, the braking force by the motor 1 rapidly decreases at the switching time t1. Therefore, in order to avoid such a situation, as shown in the graph (b), the current is increased by the control of the inverter 3 at the time t1. As a result, sufficient regenerative power (regenerative braking force) can be generated only by the first winding L1, thus preventing a sudden decrease in the braking force as described above and generating a braking force equivalent to that before switching. Can be made. Moreover, the state at the time point t1 where power is generated using only the first winding L1 is compared to the state before the time point t1 where power is generated by both the first winding L1 and the second winding L2 (low speed mode). Since the power generation efficiency is lowered, the charging power to the battery 2 can be reduced by that amount. In graph (f), the decrease in charging power due to the decrease in power generation efficiency is represented as ΔZ.

  Even after the time point t1 when the mode is switched to the regenerative power generation suppression mode, the charge amount SOC gradually increases (although the increase rate decreases). Then, along with this, the duty ratio in the switching control of the second switch SW2 is gradually increased toward 100% (see graph (d)). As the duty ratio increases, the ratio of the period in which the second switch SW2 is turned on within a certain period increases (in other words, the ratio of the period in which the second switch SW2 is turned off decreases). On the other hand, after time t1, as shown in the graph (b), the regenerative current flowing through the first winding L1 is gradually reduced by the control of the inverter 3 in order to suppress the charging power to the battery 2. As a result of these controls, the ratio of the regenerative current (Ig in FIG. 9) flowing through the first winding L1 gradually decreases, and the ratio of the circulating current (Ic in FIG. 9) circulating through the second winding L2 gradually increases. growing. Thereby, the charging power to the battery 2 gradually decreases with time, and the increasing rate of the charge amount SOC gradually decreases (see graphs (e) and (f)).

  Although the charging power to the battery 2 gradually decreases by the operation in the regenerative power generation suppression mode as described above, this state is continued, so that the charging amount SOC finally reaches the second threshold value X2 (that is, the battery 2 is fully charged). In FIG. 12, this time is set as t3. At this time t3, the motor 1 shifts to the regenerative power generation prohibition mode. That is, while the first switch SW1 is turned on, the second switch SW2 is switched from the switching control state (a state where ON / OFF is repeated) to ON (see graphs (c) and (d)), and further, the inverter 3 Is stopped. As a result, the current generated in the motor 1 is only the circulating current Ic that circulates through the second winding L2, so that no electric power is charged in the battery 2, and the amount of charge SOC is maintained at the second threshold value X2.

  A graph (a) in FIG. 12 shows how the motor braking force changes when the above operation is performed. As shown in the graph, before the time point t1 when the low speed mode is selected, the braking force applied from the motor 1 to the wheel 8 is all regenerative braking (the first winding L1 and the second winding L2). Braking force by regenerative braking). On the other hand, when the transition to the regenerative power generation suppression mode is made after time t1, the ratio of the regenerative braking force in the braking force gradually decreases with time, and conversely, the short-circuit braking force (second winding) by the second winding L2. The ratio of the braking force based on the circulating current Ic of the line L2 gradually increases. Here, since there is a limit to the braking force that can be generated by the short-circuit braking, the duty ratio of the second switch SW2 reaches 100% at the time t2 in the middle of the regenerative power generation suppression mode, as in the example of the graph, The short circuit braking force may reach the maximum value. In this case, there is no shortage of the net braking force of the motor 1 that is the sum of the regenerative braking force and the short-circuit braking force from the time point t1 when the mode is changed to this time point t2, but after the time point t2, the short-circuit braking force is not generated. Thus, the net braking force of the motor 1 gradually decreases with time. The insufficient braking force generated thereby is compensated by the brake device 10. Furthermore, after shifting to the regenerative power generation prohibition mode after time t3, all of the braking force applied from the motor 1 to the wheels 8 becomes braking force due to short-circuit braking. The insufficient braking force generated in this case is also compensated by the brake device 10.

(5) Operation, etc. As described above, in this embodiment, the motor 1 is controlled in the following pattern when the vehicle is not powered.
● When the charge amount SOC of the battery 2 is in a low charge state less than the first threshold value X1 and the rotational speed of the motor 1 is less than the reference speed Nx → the regenerative braking force by the first winding L1 and the second winding L2 As occurs, the first switch SW1 is turned off and the second switch SW2 is turned on (low speed mode).
When the charge amount SOC of the battery 2 is in a low charge state less than the first threshold value X1 and the rotational speed of the motor 1 is equal to or higher than the reference speed Nx → the regenerative braking force is generated by the first winding L1 and the second winding The first switch SW1 is turned on and the second switch SW2 is turned off (high speed mode) so that the regenerative braking force due to L2 is not generated.
When the charge amount SOC of the battery 2 is in a high charge state that is equal to or greater than the first threshold value X1 and less than the second threshold value X2, the regenerative braking force by the first winding L1 and the short-circuit braking force by the second winding L2 are generated. First, the first switch SW1 is turned on, and the second switch SW2 is switched (repeatedly ON / OFF) (regenerative power generation suppression mode).
● When the charge amount SOC of the battery 2 is in a fully charged state greater than or equal to the second threshold value X2 → An inverter so that a short-circuit braking force is generated by the second winding L2 and no regenerative braking force is generated by the first winding L1 3 is stopped and both the first switch SW1 and the second switch SW2 are turned on (regenerative power generation prohibition mode).

  In the above-described embodiment in which such control is performed when the vehicle is not in powering, the vehicle is decelerated due to the adjustment of the generated power while appropriately adjusting the generated power according to the charge amount SOC of the battery 2. There is an advantage that can be effectively prevented.

  That is, in the above embodiment, when the battery 2 is in a low charge state (SOC <X1), whether the regenerative braking force is generated by the first winding L1 and the second winding L2 according to the rotational speed of the motor, Alternatively, the switches SW1 and SW2 are controlled so that the regenerative braking force is generated only by the first winding L1 (low speed mode or high speed mode). As a result, the electric power generated by the motor 1 can be charged into the battery 2 having a sufficient free capacity to increase the amount of charge SOC, and the required braking force can be applied from the motor 1 to the wheels 8. it can.

  On the other hand, when the amount of charge SOC increases and the battery 2 is in a high charge state (X1 ≦ SOC <X2), a regenerative braking force by the first winding L1 and a short-circuit braking force by the second winding L2 are generated. Thus, the switches SW1 and SW2 are controlled (regenerative power generation suppression mode). Thus, by covering a part of the braking force applied to the wheels 8 with the short-circuit braking force, the regenerative braking force can be reduced and the electric power charged in the battery 2 can be reduced. That is, the short-circuit braking force is based on the circulating current Ic that circulates through the second winding L2, and since this circulating current Ic does not flow to the battery 2, even if the short-circuit braking force is generated, the battery 2 The amount of charge SOC does not increase. On the other hand, although the generated power corresponding to the regenerative braking force is turned to charge the battery 2, the regenerative braking force can be reduced by the presence of the short-circuit braking force, so the power charged to the battery 2 is reduced. be able to. In addition, the net braking force by the motor 1, that is, the sum of the regenerative braking force and the short-circuit braking force, does not need to be greatly reduced compared to the case where there is no short-circuit braking force (particularly until the short-circuit braking force reaches the maximum value). Since the net braking force can be kept the same during this period, it is possible to effectively prevent the feeling of slowdown from occurring.

  When the amount of charge SOC further increases and the battery 2 becomes fully charged (SOC ≧ X2), the inverter 3 and the switches SW1 and SW2 are controlled so that only the short-circuit braking force is generated by the second winding L2. (Regenerative power generation prohibition mode). As a result, power generation by the motor 1 is not performed, so that it is possible to reliably prevent a situation in which the battery 2 is charged and damaged even though the battery 2 is in a fully charged state. it can.

  In particular, in the above embodiment, the duty ratio in the switching control of the second switch SW2 increases as the charge amount SOC of the battery 2 increases in the regenerative power generation suppression mode in which both the regenerative braking force and the short-circuit braking force are generated. Therefore, it is possible to reliably prevent a sudden decrease in braking force.

  That is, during the regenerative power generation suppression mode, the duty ratio control as described above is performed, so that the ratio of the regenerative braking force gradually decreases and the ratio of the short-circuit braking force gradually increases, which leads to a feeling of slowdown. It is possible to effectively suppress an increase in the charge amount SOC while reliably preventing such a sudden decrease in braking force.

  Here, in the power generation suppression mode or the regenerative power generation prohibition mode, although the short-circuit braking force is added, the regenerative braking force is reduced, so that the short-circuit braking force is generally much smaller than the maximum value of the regenerative braking force. Considering this, it can be said that the situation where the net braking force by the motor 1 is insufficient is more likely to occur than in the low speed mode or the high speed mode. However, in the above embodiment, the sum of the braking force by the motor 1 and the braking force by the brake device 10 matches the target braking force (target total braking force) set based on the operation amount of the brake pedal or the like. Since the brake device 10 is controlled (a so-called cooperative regenerative braking system), the brake device 10 can compensate for a shortage of braking force applied from the motor 1 to the wheels 8, and the stable braking force regardless of the state of the battery 2. Can be applied to the wheel 8. Further, since the braking force by the brake device 10 can be reduced by the amount of braking force by the motor 1, the amount of wear on the brake pads can be reduced.

  In the above embodiment, during non-powering when the battery 2 is in a high charge state (X1 ≦ SOC <X2), regardless of the rotational speed of the motor 1 (whether higher or lower than the reference speed Nx), The regenerative power generation suppression mode in which the first switch SW1 is turned on and the second switch SW2 is controlled to switch is selected. However, in the low speed range where the rotational speed of the motor 1 is lower than the reference speed Nx, it is different from this. It is also possible to adopt this mode. For example, as shown in FIG. 13, when the rotational speed is less than the reference speed Nx (low speed range) during non-powering in a high charge state, the first switch SW1 is turned on and the second switch SW2 is turned off. It is conceivable to select the high speed mode. In the high speed mode, power generation is performed using only the first winding L1, so that the power generation efficiency is lower than in the low speed mode in which power generation is performed using both the first winding L1 and the second winding L2. For this reason, even if a braking force equivalent to that in the low-speed mode is generated, the power charged in the battery 2 can be reduced (see ΔZ in the graph (f) in FIG. 12).

  Further, in the above embodiment, when the battery 2 is in a non-powering state when the battery 2 is in a low charge state (SOC <X1) and the rotational speed of the motor 1 is equal to or higher than the reference speed Nx (high speed range), The high speed mode in which the first switch SW1 is turned on and the second switch SW2 is turned off is selected. However, the low speed mode may be selected depending on circumstances. For example, some vehicles may be provided with a mode selection switch for switching the running mode of the vehicle between a sports mode and other modes (for example, a normal mode, an eco mode, etc.). When the sport mode (S mode) is selected by this mode selection switch, as shown in FIG. 14, the low speed mode is selected even if the rotational speed is in the high speed range equal to or higher than the reference speed Nx. It can be considered that the first switch SW1 is turned off and the second switch SW2 is turned on. As described above, when the low speed mode in which power is generated using both the first winding L1 and the second winding L2 is selected, the braking force that can be generated is increased as compared with the high speed mode. Accordingly, the vehicle can be decelerated relatively rapidly, and a sporty ride can be realized.

  Moreover, in the said embodiment, IGBT which can perform switching control as a switching means for switching the operation mode of the motor 1 between several modes (low speed mode, high speed mode, regenerative power generation suppression mode, and regenerative power generation prohibition mode). Although the first and second switches SW1 and SW2 made of semiconductor elements such as are provided, the example of the switching means is not limited to this. For example, a switch using a variable resistor may be used. In this case, by continuously changing the resistance value, it is possible to obtain the same effect as when the duty ratio of the switching control is continuously changed.

  Moreover, although the said embodiment demonstrated the example which applied this invention to the electric vehicle which used only the electric motor 1 as a motive power source, the vehicle which can apply this invention has an electric motor at least as a part of motive power source. As long as it is used, the present invention can be suitably applied to a hybrid vehicle using both an internal combustion engine and an electric motor.

1 Motor 2 Battery 3 Inverter 4 Controller (control means)
10 Brake device L1 1st winding L2 2nd winding SW1 1st switch (switching means)
SW2 Second switch (switching means)
Nx reference speed X1 first threshold (reference charge)
Ic Circulating current

Claims (7)

A motor capable of driving wheels during power running and generating power during non-power running to generate braking force, a battery capable of charging the power generated by the motor, and converting the power charged in the battery into AC power An electric vehicle drive device comprising an inverter for supplying to a motor while a control means for controlling the motor and the inverter,
The motor has a first winding and a second winding connected in series, and switching means for switching the energization state of each winding,
The switching means is in a state where a current flows through both the first winding and the second winding, a state where a current flows only through the first winding, and a state where the circulating current flows through the second winding. Can be switched between
The control means includes
When the rotational speed of the motor is less than a predetermined reference speed during non-powering in a low charge state where the charge amount of the battery is less than a predetermined reference charge amount, the first winding And controlling the switching means so that a regenerative braking force is generated by the second winding,
When the battery is in the low charge state, when the rotational speed is equal to or higher than the reference speed, the switching unit is controlled so that at least the regenerative braking force is generated by the first winding,
When the rotational speed is less than the reference speed during non-powering when the charge amount of the battery is higher than the reference charge amount, a regenerative braking force is generated by the first winding and the Controlling the switching means so as not to generate regenerative braking force by the second winding;
When the battery is in the high charging state and the rotational speed is equal to or higher than the reference speed, a regenerative braking force by the first winding and a short-circuit braking force by the second winding are generated. The switching means is controlled as described above. The drive device for an electric vehicle according to claim 1,
When the rotation speed is less than the reference speed during non-powering when the battery is in the high charge state, the control means is configured to cause a regenerative braking force by the first winding and a short circuit by the second winding. The drive device for an electric vehicle, wherein the switching means is controlled so that a braking force is generated. The drive device for an electric vehicle according to claim 2,
The control means is configured to decrease the regenerative braking force ratio and increase the short-circuit braking force ratio as the charge amount of the battery increases during non-powering when the battery is in the high charge state. A drive device for an electric vehicle. The drive device for an electric vehicle according to claim 3,
The switching means includes a semiconductor element capable of switching a short circuit / non-short circuit of the second winding based on switching ON / OFF,
The drive means for an electric vehicle, wherein the control means controls a ratio of a short-circuit braking force by the second winding based on a duty ratio of the semiconductor element. In the electric vehicle drive device according to any one of claims 1 to 4,
The vehicle is equipped with a brake pedal operated by a driver and a hydraulic brake device that imparts braking force by friction to the wheels,
The control means sets a target braking force according to an operation amount of the brake pedal, and the brake device so that a sum of a braking force by the brake device and a braking force by the motor matches the target braking force. The drive device for electric vehicles characterized by having the function to control. In the electric vehicle drive device according to any one of claims 1 to 5,
When the battery is in the low charge state and in the non-powering mode, when the rotational speed is equal to or higher than the reference speed, a regenerative braking force is generated by the first winding and a regenerative braking force is generated by the second winding. The drive device for an electric vehicle, wherein the switching means is controlled so as not to occur. In the electric vehicle drive device according to any one of claims 1 to 5,
The vehicle is equipped with a mode selection switch for switching the driving mode of the vehicle between the sports mode and the other modes,
When the rotational speed is equal to or higher than the reference speed during non-powering when the sport mode is selected by the mode selection switch and the battery is in the low charge state, the control means The drive device for an electric vehicle, wherein the switching means is controlled so that a regenerative braking force is generated by the wire and the second winding.

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