Control method and control apparatus for motor of electric vehicle, and electric vehicle including the control apparatus

Abstract

The invention discloses a control method and a control apparatus for a motor of an electric vehicle, and an electric vehicle including the control apparatus. The control method includes: setting a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by a motor; and calculating a torque upper limit value of a command torque for commanding the motor to maintain a state in which the current-related value is equal to or less than the current-related upper limit value, based on an accelerator operation amount and the current-related upper limit value input to the electric vehicle.

Description

Technical Field

[0001] The present disclosure relates to a control method and a control apparatus for a motor of an electric vehicle, and an electric vehicle including the control apparatus. Background Art

[0002] JP2010-233396A discloses a control method and a control device for a motor of an electric vehicle, and an electric vehicle including the control device.

[0003] According to JP2010-233396A, an upper limit value of the discharge power of the battery is set, and the discharge power of the battery is reduced to the upper limit value or less.

[0004] In order to reduce the discharge power of the battery, it is necessary to add additional functions or components to the battery or a battery control circuit electrically connected to the battery, such as incorporating a current limiting function into the battery or the battery control circuit.

[0005] General-purpose electric vehicles require a function of reducing the discharge power of a battery in order to electrically protect battery-related components. Therefore, it is difficult to freely select and install various batteries and battery control circuits in general-purpose electric vehicles. Summary of the invention

[0006] The present disclosure provides a control method capable of electrically protecting battery-related components and expanding options for batteries and battery control circuits to be installed.

[0007] According to an illustrative aspect of the present disclosure, a control method for a motor of an electric vehicle includes: setting a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by the motor; and calculating a torque upper limit value of a command torque for commanding the motor to maintain a state in which the current-related value is equal to or less than the current-related upper limit value based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value.

[0008] According to the present disclosure, a control method for a motor of an electric vehicle calculates a torque upper limit value of a command torque to be issued to the motor so that a current-related value related to a current flowing through a battery is equal to or less than a current-related upper limit value. By calculating the torque upper limit value of the command torque, battery-related components can be electrically protected even when a battery with a small allowable current is installed or even when a battery and a battery control circuit without a current limiting function are installed. Therefore, the electric vehicle has a function of protecting battery-related components, and various batteries and battery control circuits can be freely selected and installed.

[0009] Therefore, according to the control method of a motor for an electric vehicle of the present disclosure, battery-related components can be electrically protected, and options for installed batteries and battery control circuits can be expanded. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a side view of an electric vehicle according to an embodiment of the present disclosure.

[0011] Figure 2 yes Figure 1 Circuit diagram of an electric vehicle.

[0012] Figure 3 is included Figure 2 Circuit diagram of a battery in a circuit.

[0013] Figure 4 is shown for controls that are included Figure 2 A block diagram of the system of the motor in the circuit.

[0014] Figure 5 When Figure 4 The current-related upper limit value in the diagram sets the upper limit current when the battery is discharged in the circuit used.

[0015] Figure 6 When Figure 4 The current-related upper limit value in the diagram sets the upper limit current when the battery is charged using the circuit.

[0016] Figure 7 It is shown by Figure 4 A graph of one embodiment of the command torque corrected by the command torque calculation circuit shown in FIG.

[0017] Figure 8 It is shown by Figure 4 0 is a graph of another embodiment of the command torque corrected by the command torque calculation circuit in FIG.

[0018] Fig. 9 Is Figure 2 Flowchart of motor control performed by the circuit in FIG. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0020] Electric vehicle configuration

[0021] Figure 1 1 is a side view of an electric vehicle (hereinafter referred to as an "electric motorcycle") 1 according to an embodiment of the present disclosure. Directions such as the forward direction, the backward direction, the right direction, and the left direction are directions viewed from a driver riding on the electric motorcycle 1 in this embodiment.

[0022] The electric motorcycle 1 includes a main body 2 of the electric motorcycle 1 , a front wheel 3 provided in front of the main body 2 , and a rear wheel 4 provided behind the main body 2 .

[0023] The front wheel 3 is rotatably supported by the lower portion of the front fork 5 extending in the up-down direction. The front fork 5 is supported by a steering shaft 8 via an upper bracket 6 provided at an upper end portion thereof and a lower bracket 7 provided below the upper bracket 6. The steering shaft 8 is pivotally supported by a head pipe 9 attached to the body 2.

[0024] A handlebar 10 extending in the left-right direction is attached to the upper bracket 6. The front wheel 3 is steered with the steering shaft 8 as a rotation axis by the driver swinging the handlebar 10 left and right.

[0025] The accelerator grip 11 is rotatably attached to both sides of the handlebar 10. When starting or accelerating the electric motorcycle 1, the driver issues a start request or an acceleration request by rotating the accelerator grip 11. The accelerator grip 11 includes an accelerator grip sensor 12 electrically connected to a control unit 24 to be described later. The accelerator grip sensor 12 detects an accelerator operation amount input by rotating the accelerator grip 11, and transmits a signal including the accelerator operation amount to the control unit 24.

[0026] A drive system component 13 that drives the rear wheel 4 is disposed inside the body 2 in the vehicle width direction so as to drive the electric motorcycle 1. The drive system component 13 includes a motor 14 and a power transmission component 15. The motor 14 generates a driving force when electric power is supplied. In the present embodiment, the motor 14 is a three-phase AC motor. The power transmission component 15 connects the output shaft of the motor 14 and the rear wheel, which is a driving wheel, in a power-transmittable manner. The power transmission component 15 includes, for example, a sprocket and a chain, and transmits the driving force of the motor 14 to the rear wheel 4. In addition, the electric motorcycle 1 includes a motor rotation speed sensor 16 that is electrically connected to a control unit 24 described later, near the motor 14. The motor rotation speed sensor 16 detects the rotation speed of the motor 14 and transmits a signal including the rotation speed to the control unit 24.

[0027] Two chargeable and dischargeable battery packs 17, 18 that supply electric power to the motor 14 are provided inside the body 2 in the vehicle width direction. The two battery packs 17, 18 are attachable to and detachable from the body 2. Each battery pack can be charged by an external charging device in a state of being detached from the body 2. The charged battery pack is attached to the body 2 by the user. In the present embodiment, two battery packs 17, 18 are provided, but one or three or more battery packs may be provided.

[0028] Battery attachment detection sensors 19, 20 that detect whether the two battery packs 17, 18 are attached are provided inside the body 2 in the vehicle width direction. The battery attachment detection sensors 19, 20 detect whether the two battery packs 17, 18 are attached to the body 2, and transmit a signal indicating whether the two battery packs 17, 18 are attached to the body 2 to a control unit 24 described later.

[0029] The motor driver 21 is provided inside the body 2 in the vehicle width direction. The motor driver 21 is electrically connected to the motor 14, and controls electric power supplied from the battery packs 17, 18 to the motor 14, thereby controlling the driving torque output from the motor 14.

[0030] The switch box 22 is provided inside the body 2 in the vehicle width direction. The switch box 22 controls the electrical connection between the two battery packs 17, 18 and the motor 14 so as to be able to select a parallel connection state in which both of the two battery packs 17, 18 supply electric power to the motor 14 or a single connection state in which one of the battery packs 17, 18 supplies electric power to the motor 14.

[0031] A wheel speed sensor 23 that detects the rotation speed of the front wheel 3 is provided below the front fork 5. The wheel speed sensor 23 transmits a signal including the rotation speed of the front wheel 3 to a control unit 24 described later.

[0032] The control unit 24 is provided inside the body 2 in the vehicle width direction. The control unit 24 is electrically connected to electrical components such as the accelerator grip sensor 12, the motor rotation speed sensor 16, the battery attachment detection sensors 19, 20, the motor driver 21, the switch box 22, and the wheel speed sensor 23. The control unit 24 is an integrated circuit that controls the drive system components 13 (particularly the motor 14) according to a signal transmitted from the accelerator grip sensor 12 or the like, and includes a processor 24a that performs control processing, a memory 24b that stores a control program, and an input and output interface 24c that transmits and receives signals to and from the above-mentioned electrical components.

[0033] In this embodiment, the control unit 24 is electrically connected to the two battery packs 17, 18 and performs control to allow charging and discharging. On the other hand, in addition to the control unit 24, a battery control device that controls the charging and discharging of the two battery packs 17, 18 can be set inside the body 2 in the vehicle width direction.

[0034] Circuit Configuration

[0035] Figure 2 yes Figure 11 is a circuit diagram of an electric motorcycle, and particularly shows a circuit 25 electrically connecting a motor 14, two battery packs 17, 18, a motor driver 21, a switch box 22 and a control unit 24.

[0036] In the present embodiment, the circuit 25 includes a power path 26 that connects the two battery packs 17, 18 in parallel with each other and electrically connects the two battery packs 17, 18 to the motor 14 via an inverter circuit 27 described later. The electric power path 26 is an electric power path that supplies electric power from the two battery packs 17, 18 to the motor 14 and supplies electric power from the motor 14 to the two battery packs 17, 18.

[0037] The circuit 25 includes an inverter circuit 27 that adjusts the frequency of AC power supplied from the two battery packs 17 and 18 to the motor 14 or from the motor 14 to the two battery packs 17 and 18. The inverter circuit 27 includes switching elements 27a to 27f connected in a three-phase bridge manner. Each of the switching elements 27a to 27f is a MOSFET, and its gate is electrically connected to the motor driver 21.

[0038] Each of the switching elements 27a to 27f has a closed characteristic so as to conduct between the source and the drain when a voltage is applied to the gate, and an open characteristic so as not to conduct between the source and the gate when no voltage is applied to the gate. Therefore, the motor driver 21 controls the voltage applied to the gates of the switching elements 27a to 27f to switch the opening and closing of the switching elements 27a to 27f, thereby adjusting the frequency of the AC power supplied from the two battery packs 17, 18 to the motor 14 or from the motor 14 to the two battery packs 17, 18.

[0039] The motor driver 21 is an integrated circuit electrically connected to the control unit 24 , and drives the motor 14 by controlling the inverter circuit 27 according to an electric signal transmitted from the control unit 24 and including an instruction to output a command torque to the motor 14 .

[0040] As described above, by switching the switch elements 27a to 27f open and closed, the motor driver 21 is configured to supply electric power from the two battery packs 17, 18 to the motor 14 to drive the motor 14 when the electric motorcycle 1 is running. By switching the switch elements 27a to 27f open and closed, the motor driver 21 is configured to supply electric power from the motor 14 to the two battery packs 17, 18 to charge the two battery packs 17, 18 during regenerative braking of the electric motorcycle 1.

[0041] The two battery packs 17, 18 include battery management units 17f, 18f described later, respectively, which are electrically connected to the control unit 24. The battery management units 17f, 18f perform control to allow or prohibit discharge or charge of the battery packs 17, 18, acquire information such as temperature and SOC (state of charge) of the battery packs 17, 18, and transmit the information to the control unit 24 as electrical signals.

[0042] The circuit 25 includes battery attachment detection sensors 19, 20. The battery attachment detection sensors 19, 20 are electrically connected to the positive and negative sides of the battery packs 17, 18 so as to be able to detect the potential of the battery packs 17, 18. The battery attachment detection sensors 19, 20 are electrically connected to the control unit 24, respectively. When detecting the potential of the battery packs 17, 18, the battery attachment detection sensors 19, 20 transmit an electrical signal including the potential of the battery packs 17, 18 to the control unit 24. The control unit 24 determines that the battery packs 17, 18 are attached based on the fact that the potential of the battery packs 17, 18 is detected. When the battery attachment detection sensors 19, 20 do not detect the potential of the battery packs 17, 18, the battery attachment detection sensors 19, 20 transmit an electrical signal including the potential of the battery packs 17, 18 is not detected to the control unit 24. The control unit 24 determines that the battery packs 17, 18 are not attached based on the fact that the potential of the battery packs 17, 18 is not detected.

[0043] exist Figure 2 In the embodiment shown in , the two battery packs 17, 18 are electrically connected to the power path 26, but only one of the battery packs 17, 18 may be electrically connected to the power path 26. In this case, the control unit 24 determines that only one of the two battery packs 17, 18 is electrically connected to the electric power path 26 based on the potentials of the battery packs 17, 18 transmitted from the battery attachment detection sensors 19, 20.

[0044] The circuit 25 includes switch elements 28, 29 electrically connected to the battery packs 17, 18 and the power path 26. The switch elements 28, 29 are electrically connected to the switch box 22, respectively. The switch elements 28, 29 switch between conduction and interruption between the battery packs 17, 18 and the power path 26 according to the instructions for conduction and interruption and the electrical signal transmitted from the switch box 22. In the present embodiment, the switch elements 28, 29 are relay elements, but may also be MOSFETs.

[0045] The switch box 22 is an integrated circuit electrically connected to the control unit 24, and switches between conduction and interruption between the two battery packs 17, 18 and the inverter 27 via the power path 26 by operating the switching elements 28, 29 according to an electrical signal transmitted from the control unit 24 and including an instruction to switch between conduction and interruption between the two battery packs 17, 18 and the power path 26.

[0046] Battery Pack Configuration

[0047] Figure 3 is included Figure 2 25 in the circuit diagram of the battery pack 17. In the present embodiment, the battery pack 17 has a general configuration that does not include special specifications. Since the battery pack 18 has the same configuration as the battery pack 17, the description thereof is omitted.

[0048] The battery pack 17 includes a battery unit 17a that charges and discharges electric power supplied to the motor 14. In the present embodiment, the battery unit 17a includes a plurality of battery cells, but may include a single battery cell.

[0049] In this embodiment, the battery pack 17 includes a charging switch element 17b electrically connected to the battery cell 17a, a discharge rectifier diode 17c electrically connected in parallel to the charging switch element 17b, a discharge switch element 17d electrically connected to the battery cell 17a via the charging switch element 17b and the discharge rectifier diode 17c, and a charging rectifier diode 17e electrically connected in parallel to the discharge switch element 17d.

[0050] The discharge rectifier diode 17c allows current to flow from the battery cell 17a to the inverter circuit 27 and blocks current from flowing from the inverter circuit 27 to the battery cell 17a. The charge rectifier diode 17e allows current to flow from the inverter circuit 27 to the battery cell 17a and blocks current from flowing from the battery cell 17a to the inverter circuit 27.

[0051] The battery pack 17 includes a battery management unit 17f electrically connected to the charging switch element 17b and the discharging switch element 17d. The battery management unit 17f switches between the opening and closing of the charging switch element 17b and the discharging switch element 17d to control the permission or prohibition of the discharge or charging of the battery pack 17. In addition, the battery management unit 17f is electrically connected to the control unit 24, receives an electrical signal including an instruction to permit or prohibit the discharge or charging of the battery pack 17, and transmits an electrical signal including information such as the temperature and SOC (state of charge) of the battery pack 17 and information on the current flowing through the battery cell 17a.

[0052] In the present embodiment, each of the charge switch element 17 b and the discharge switch element 17 d is a MOSFET having a gate electrically connected to the battery management unit 17 f , but may be other relay elements.

[0053] Each of the charging switch element 17b and the discharging switch element 17d has a closed characteristic so as to conduct between the source and the drain when a voltage is applied to the gate, and an open characteristic so as not to conduct between the source and the gate when a voltage is not applied to the gate. Therefore, by controlling the voltage applied to the gate of the charging switch element 17b, the battery management unit 17f selectively switches between a chargeable state that allows current to flow from the inverter circuit 27 to the battery cell 17a and a charge-inhibited state that prohibits current from flowing from the inverter circuit to the battery cell 17a. More specifically, the battery management unit 17f switches the battery pack 17 to a chargeable state by closing the charging switching element 17b. The battery management unit 17f switches the battery pack 17 to a charge-inhibited state by opening the charging switching element 17b.

[0054] By controlling the voltage applied to the gate of the discharge switch element 17d, the battery management unit 17f selectively switches between a dischargeable state that allows current to flow from the battery cell 17a to the inverter circuit 27 and a discharge prohibited state that prohibits current from flowing from the battery cell 17a to the inverter circuit 27. More specifically, the battery management unit 17f switches the battery pack 17 to the dischargeable state by closing the discharge switch element 17d. The battery management unit 17f switches the battery pack 17 to the discharge prohibited state by opening the discharge switch element 17d.

[0055] The battery management unit 17f can switch the battery pack 17 to a chargeable state and a dischargeable state by closing both the charge switch element 17b and the discharge switch element 17d. In addition, the battery management unit 17f can switch the battery pack to a charge prohibited state and a discharge prohibited state by opening both the charge switch element 17b and the discharge switch element 17d.

[0056] The battery management unit 17f is an integrated circuit that switches the dischargeable state, the discharge prohibited state, the chargeable state, and the charge prohibited state of the battery pack 17 by controlling the voltage applied to the gates of the charge switch element 17b and the discharge switch element 17d.

[0057] When the SOC of the battery cell 17a approaches 100%, the battery cell 17a may deteriorate. Therefore, when it is determined that the SOC of the battery cell 17a is close to 100%, the battery management unit 17f disconnects the charging switch element 17b to switch the battery pack 17 to a charging prohibited state in order to prevent the degradation of the battery cell 17a. When the battery management unit 17f determines via the temperature sensor 17h described later that the temperature of the battery pack 17 has reached a temperature condition that prohibits charging, the battery management unit 17f similarly disconnects the charging switch element 17b to switch the battery pack 17 to a charging prohibited state in order to prevent the degradation of the battery cell 17a. In addition, when the electric motorcycle 1 is running, the battery management unit 17f can disconnect the charging switching element 17b to switch the battery pack 17 to a charging prohibited state in order to prevent accidental charging.

[0058] The discharge rectifier diode 17c and the charge rectifier diode 17e each have an allowable current, which is the upper limit value of the current flowing through the discharge rectifier diode 17c and the charge rectifier diode 17e. As described above, when the battery pack 17 is in the charge prohibited state and the dischargeable state, that is, when the charge switch element 17b is turned off and the discharge switch element 17d is closed, when the current flows from the battery cell 17a to the inverter circuit 27, a large current easily flows through the discharge rectifier diode 17c. Therefore, the current flowing through the discharge rectifier diode 17c may exceed the allowable current. When the current flowing through the discharge rectifier diode 17c exceeds the allowable current, the discharge rectifier diode 17c may be damaged.

[0059] The battery pack 17 includes a potential measurement circuit 17g that measures the potential of the battery cell 17a, a temperature sensor 17h that measures the temperature of the battery pack 17, and a current measurement circuit 17i that measures the current flowing through the battery cell 17a.

[0060] The potential measurement circuit 17g is electrically connected to the positive and negative electrodes of the battery cell 17a and the battery management unit 17f, and transmits a signal including the measured potential to the battery management unit 17f.

[0061] The temperature sensor 17h is electrically connected to the battery management unit 17f, and transmits a signal including the temperature of the battery pack 17 to the battery management unit 17f.

[0062] The current measurement circuit 17i is electrically connected to the battery cell 17a and the battery management unit 17f via the charging switching element 17b, the discharging rectifying diode 17c, the discharging switching element 17d, and the charging rectifying diode 17e, and transmits a signal including the measured current to the battery management unit 17f.

[0063] The battery management unit 17f is electrically connected to the control unit 24, calculates the SOC of the battery cell 17a from the potential of the battery cell 17a, and transmits an electrical signal including the potential and SOC of the battery cell 17a, the temperature of the battery pack 17, and the current flowing through the battery cell group 17a to the control unit 24.

[0064] In the present embodiment, when there is an abnormality (such as a short circuit or disconnection) in the circuits of the battery packs 17 and 18, the battery management units 17f and 18f transmit an electrical signal including error information to the control unit 24. When the control unit 24 receives the electrical signal including error information from any one of the battery management units 17f and 18f, the control unit 24 disconnects the charging switch elements 17b and 18b and the discharging switch elements 17d and 18d via the battery management units 17f and 18f, respectively, and switches the battery packs 17 and 18 having the abnormality to the discharge inhibition state and the charge inhibition state.

[0065] Switch Box Configuration

[0066] exist Figure 2 In the embodiment shown in FIG, the switch box 22 operates the switch elements 28 , 29 based on the electrical signal transmitted from the control unit 24 to switch between connecting the two battery packs 17 , 18 in parallel to the power path 26 and connecting only one of the two battery packs 17 , 18 to the power path 26 .

[0067] If the potential difference between the battery cells 17a, 18a is equal to or less than a predetermined threshold value based on the potentials of the battery cells 17a, 18a included in the electrical signal transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electrical signal including an instruction to connect the two battery packs 17, 18 in parallel to the switch box 22. When the switch box 22 receives the electrical signal including the instruction to connect the two battery packs 17, 18 in parallel from the control unit 24, the switch box 22 closes the switch elements 28, 29 and connects the two battery packs 17, 18 in parallel to the inverter circuit 27 via the power path 26. Since the two battery packs 17, 18 are electrically connected to the inverter circuit 27 in parallel via the electrical power path 26, when the electric motorcycle 1 is traveling, the motor 14 is driven by the electrical power supplied from the two battery packs 17, 18, and during regenerative braking of the electric motorcycle 1, the two battery packs 17, 18 are charged by the electrical power supplied from the motor 14.

[0068] When the electric motorcycle 1 is running, if the potential difference between the battery cells 17a, 18a is greater than a predetermined threshold value based on the potentials of the battery cells 17a, 18a included in the electrical signals transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electrical signal including an instruction to connect the battery cell with a higher potential among the two battery packs 17, 18 to the switch box 22. When the switch box 22 receives the electrical signal including an instruction to connect the battery cell with a higher potential among the two battery packs 17, 18 from the control unit 24, the switch box 22 closes one of the switch elements 28, 29 and connects the battery cell with a higher potential among the two battery packs 17, 18 to the inverter circuit 27 via the power circuit 26. Since one of the battery packs 17, 18 is electrically connected to the inverter circuit 27 via the electrical power path 26, when the electric motorcycle 1 is running, the motor 14 is driven by the electrical power supplied from one of the battery packs 17, 18.

[0069] When the electric motorcycle 1 performs regenerative braking, if the potential difference between the battery cells 17a, 18a is greater than a predetermined threshold value based on the potentials of the battery cells 17a, 18a included in the electrical signal transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electrical signal including an instruction to connect the battery cell with the lower potential among the two battery packs 17, 18 to the switch box 22. When the switch box 22 receives the electrical signal including the instruction to connect the battery cell with the lower potential among the two battery packs 17, 18 from the control unit 24, the switch box 22 closes one of the switch elements 28, 29 and connects the battery cell with the lower potential among the two battery packs 17, 18 to the inverter circuit 27 via the power circuit 26. Since one of the battery packs 17, 18 is electrically connected to the inverter circuit 27 via the electrical power path 26, when the electric motorcycle performs regenerative braking, one of the battery packs 17, 18 is charged by the electrical power supplied from the motor 14.

[0070] Even in the case where the motor 14 is driven by the electric power supplied from one of the battery packs 17, 18, or in the case where one of the battery packs 17, 18 is charged by the electric power supplied from the motor 14, if it is determined that the potential difference between the battery cells 17a, 18a is equal to or less than the predetermined threshold value based on the potentials of the battery cells 17a, 18a included in the electric signal transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electric signal including an instruction to switch the state in which only one of the two battery packs 17, 18 is connected to the state in which the two battery packs 17, 18 are electrically connected in parallel to the switch box 22. Since the switch box 22 receives the electric signal including the instruction to switch the state in which only one of the two battery packs 17, 18 is connected to the state in which the two battery packs 17, 18 are electrically connected in parallel from the control unit 24, the switch box 22 closes the switch elements 28, 29 and electrically connects the two battery packs 17, 18 in parallel to the inverter circuit 27 via the power path 26.

[0071] Control unit configuration

[0072] Figure 4 is shown for controls that are included Figure 2 1 is a block diagram of a system of the motor 14 in the circuit in FIG. 1 , and particularly shows the control circuit included in the processor 24 a of the control unit 24 .

[0073] The functions implemented by the components described in this specification may be implemented in a circuit or processing circuit, which includes a general-purpose processor, a special-purpose processor, an integrated circuit, an application specific integrated circuit (ASIC), a central processing unit (CPU), a conventional circuit, and / or a combination thereof, which is programmed to implement the functions described herein. The processor includes transistors and other circuits and is considered to be a circuit or processing circuit. The processor can be a programmed processor that executes a program stored in a memory. In this specification, circuits, units, and devices are hardware-programmed to implement the functions described or hardware to be executed. The hardware can be any type of hardware disclosed in this specification, or any type of hardware that is programmed to implement the functions described above or known to be executed. When the hardware is a processor that is considered to be a circuit type, the circuit, device, or unit is a combination of hardware and software for configuring the hardware and processor.

[0074] The processor 21 a includes a current-related upper limit value setting circuit 30 , a torque upper limit value calculation circuit 31 , a command torque calculation circuit 32 , and a battery charge determination circuit 33 .

[0075] The current-related upper limit value setting circuit 30 sets the upper limit current of the battery packs 17, 18 based on the signal including the SOC of the battery cells 17a, 18a and the temperature of the battery packs 17, 18 transmitted from the battery management units 17f, 18f, and sets the current-related upper limit value of the current-related value based on the upper limit current, and the current-related value is such as the electric power related to the current and temperature flowing through the battery packs 17, 18.

[0076] In the present embodiment, the memory 24b of the control unit 24 stores a graph of the upper limit current of the SOC and temperature of the battery pack described later. The current-related upper limit value setting circuit 30 sets the upper limit current of the battery packs 17, 18 by using the graph, and sets the current-related upper limit value of the current-related value based on the upper limit current, such as the electric power related to the current and temperature flowing through the battery packs 17, 18. The memory 24b of the control unit 24 may store an arithmetic expression for calculating the upper limit current based on the SOC and temperature of the battery pack instead of the graph. In this case, the current-related upper limit value setting circuit 30 sets the upper limit current of the battery packs 17, 18 by using the arithmetic expression, and sets the current-related upper limit value of the current-related value based on the upper limit current, such as the electric power related to the current and temperature flowing through the battery packs 17, 18.

[0077] The torque upper limit value calculation circuit 31 calculates the torque upper limit value of the command torque to be issued to the motor 14 via the motor driver 21 to maintain the state where the current related value is equal to or less than the current related upper limit value based on the signal including the accelerator operation amount and the current related upper limit value transmitted from the accelerator grip sensor 12. More specifically, the torque upper limit value is calculated from the characteristics between the applied current and the output torque of the motor 14 based on the upper limit current related to the current related upper limit value.

[0078] The command torque calculation circuit 32 calculates the command torque based on the accelerator operation amount and the rotation speed of the motor 14 transmitted from the motor rotation speed sensor 16 so that the current-related value is equal to or less than the current-related upper limit value. More specifically, based on the accelerator operation amount and the rotation speed of the motor 14, the command torque is calculated to be equal to or less than the torque upper limit value so that the current-related value is equal to or less than the current-related upper limit value. When the accelerator operation amount is maximum, the command torque is calculated to increase as the accelerator operation amount increases so that the current-related value becomes the current-related upper limit value, and the command torque is also calculated to be limited to be equal to or less than the torque upper limit value.

[0079] When the electric motorcycle 1 performs regenerative braking, the battery charge determination circuit 33 determines whether to charge the battery packs 17, 18 based on the current flowing through the battery packs 17, 18. More specifically, when the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current, the battery packs 17, 18 are switched to a chargeable state, and charging is thereby performed. When the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 exceeds the upper limit current, the battery packs 17, 18 are switched to a charge prohibition state, and charging is thereby stopped.

[0080] The memory 24 b of the control unit 24 stores a processing program for executing the functions of the current-related upper limit value setting circuit 30 , the torque upper limit value calculation circuit 31 , the command torque calculation circuit 32 , and the battery charge determination circuit 33 .

[0081] The processor 24a implements the functions of the current-related upper limit value setting circuit 30, the torque upper limit value calculation circuit 31, the command torque calculation circuit 32, and the battery charge determination circuit 33 by executing a processing program for executing the functions of the current-related upper limit value setting circuit 30, the torque upper limit value calculation circuit 31, the command torque calculation circuit 32, and the battery charge determination circuit 33 stored in the memory 21b.

[0082] In this embodiment, the processor 24a independently includes a current-related upper limit value setting circuit 30, a torque upper limit value calculation circuit 31, a command torque calculation circuit 32, and a battery charging determination circuit 33 as an integrated circuit, and can be a microprocessor in which the functions of the current-related upper limit value setting circuit 30, the torque upper limit value calculation circuit 31, the command torque calculation circuit 32, and the battery charging determination circuit 33 are integrated.

[0083] Current related upper limit setting circuit

[0084] In the present embodiment, the current-related upper limit value setting circuit 30 sets the upper limit current of the current flowing through the battery packs 17 , 18 to the current-related upper limit value.

[0085] The current-related upper limit value setting circuit 30 sets the upper limit current of the battery packs 17 and 18 based on the electrical signals including the SOC of the battery cells 17a and 18a and the temperature of the battery packs 17 and 18 transmitted from the battery management units 17f and 18f, and sets the minimum upper limit current among the upper limit currents set for the battery packs 17 and 18 as the current-related upper limit value.

[0086] The upper limit current of the battery packs 17, 18 varies depending on whether the battery packs 17, 18 are in a discharging state or in a charging state. More specifically, when the battery packs 17, 18 are in a discharging state, the upper limit current of the battery packs 17, 18 is set to a larger value than when the battery packs 17, 18 are in a charging state so that the motor 14 can output a sufficiently large torque. In order to electrically protect the battery packs 17, 18, the upper limit current of the battery packs 17, 18 when the battery packs 17, 18 are in a charging state is set to a smaller value than the upper limit current when the battery packs 17, 18 are in a discharging state.

[0087] Figure 5 Is when Figure 4 Graph of the upper limit current when the battery packs 17, 18 are in a discharge state, used by the current-related upper limit value setting circuit 30 in FIG. 1 , wherein the horizontal axis indicates the temperature of the battery packs 17, 18 and the vertical axis indicates the SOC of the battery packs 17, 18. Figure 5 In the diagram in FIG. 1 , upper limit current regions I1, I2, and I3 are determined corresponding to the temperature and SOC of the battery packs 17, 18. In each of the upper limit current regions I1, I2, and I3, the magnitude of the current value [A] has a relationship of I1>I2>I3.

[0088] Figure 5 The graph in FIG. 1 is stored in the memory 24 b of the control unit 24. The current-related upper limit value setting circuit 30 uses the current-related upper limit value setting circuit 30 based on the temperature and SOC of the battery packs 17 and 18. Figure 5 The figure shows that each of the battery groups 17 and 18 is set to an upper limit current in the corresponding areas I1, I2 and I3, and the minimum value among the upper limit currents of the battery groups 17 and 18 is set as the current-related upper limit value.

[0089] Figure 6 Is when Figure 4 Graph of the upper limit current when the battery packs 17, 18 are in a charging state, where the horizontal axis indicates the temperature of the battery packs 17, 18 and the vertical axis indicates the SOC of the battery packs 17, 18. Figure 6 In the diagram in FIG. 1 , upper limit current regions I11, I12, and I13 are determined corresponding to the temperature and SOC of the battery packs 17, 18. In each of the upper limit current regions I11, I12, and I13, the magnitude of the current value [A] has a relationship of I11>I12>I13.

[0090] Figure 6 The graph in FIG. 1 is stored in the memory 24 b of the control unit 24. The current-related upper limit value setting circuit 30 uses the temperature and SOC of the battery packs 17 and 18 to set the current-related upper limit value. Figure 6The figure shows that each of the battery groups 17 and 18 is set to an upper limit current in the corresponding areas I11, I12 and I13, and the minimum value among the upper limit currents of the battery groups 17 and 18 is set as the current-related upper limit value.

[0091] exist Figure 2 In the embodiment shown in , when two battery packs 17, 18 are electrically connected to the electric power path 26, but only one of the battery packs 17, 18 is electrically connected to the electric power path 26, the current-related upper limit value setting circuit 30 sets the upper limit current of the connected battery packs 17, 18 to the current-related upper limit value.

[0092] In the present embodiment, when the SOC of the battery cells 17a, 18a approaches 100%, when the temperature of the battery packs 17, 18 reaches a temperature condition to be prohibited, or when it is necessary to prevent the battery packs 17, 18 from being unintentionally charged, the battery management units 17f, 18f disconnect the charging switch elements 17b, 18b to switch the battery cells 17a, 18a to a charging prohibited state, so as to prevent the battery cells 17a, 18a from being overcharged and deteriorated. When the electric motorcycle 1 is running in a state where the charging switch elements 17b, 18b are disconnected, the battery management units 17f, 18f close the discharge switch elements 17d, 18d to switch the battery packs 17, 18 to a discharge state. At this time, since the current flows intensively through the discharge rectifying diodes 17c, 18c, the current flowing through the discharge rectifying diodes 17c, 18c may exceed the allowable current.

[0093] As described above, when the battery packs 17, 18 are in the charge prohibited state and the dischargeable state, the current-related upper limit value setting circuit 30 sets the allowable current of the discharge rectifying diodes 17c, 18c to the upper limit current of the battery packs 17, 18 in order to electrically protect the discharge rectifying diodes 17c, 18c. And, the current-related upper limit value setting circuit 30 sets the allowable current of the discharge rectifying diodes 17c, 18c to the minimum value of the set upper limit current of the battery packs 17, 18 as the current-related upper limit value.

[0094] Torque upper limit calculation circuit

[0095] The torque upper limit value calculation circuit 31 calculates the torque upper limit value of the command torque to be issued to the motor 14 via the motor driver 21 based on the accelerator operation amount transmitted from the accelerator grip sensor 12 and the current-related upper limit value set by the current-related upper limit value setting circuit 30, so as to maintain the state where the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current. More specifically, the torque upper limit value is calculated based on the characteristic between the applied current and the output torque of the motor 14 from the upper limit current related to the current-related upper limit value.

[0096] Command torque calculation circuit

[0097] The command torque calculation circuit 32 calculates a command torque to be issued to the motor 14 via the motor driver 21 based on the accelerator operation amount transmitted from the accelerator grip sensor 12 and the rotation speed of the motor 14 transmitted from the motor rotation speed sensor 16 .

[0098] When the command torque exceeds the torque upper limit value calculated by the torque upper limit value calculation circuit 31, the command torque calculation circuit 32 corrects the command torque so that the command torque becomes equal to or less than the torque upper limit value to maintain the state in which the current flowing through the battery packs 17 and 18 becomes equal to or less than the upper limit current.

[0099] Figure 7 It is shown by Figure 4 A graph of an embodiment of the command torque corrected by the command torque calculation circuit 32 in FIG. 1 , wherein the horizontal axis indicates the accelerator operation amount and the vertical axis indicates the command torque. Figure 7 In the graph of , the solid line indicates the transition of the command torque after correction, the single-point chain line indicates the torque upper limit value calculated by the torque upper limit value calculation circuit 31, and the dotted line indicates the transition of the command torque before correction based on the accelerator operation amount. Figure 7 As shown by the solid line in the graph of , when the command torque reaches the torque upper limit value, the command torque is corrected to the torque upper limit value, which is a stable value.

[0100] Figure 8 It is shown by Figure 4 A graph of another embodiment of the command torque corrected by the command torque calculation circuit 32 in FIG. 1 , in which the horizontal axis indicates the accelerator operation amount and the vertical axis indicates the command torque. Figure 8 In the graph of , the solid line indicates the transition of the command torque after correction, the single-point chain line indicates the torque upper limit value calculated by the torque upper limit value calculation circuit 31, and the dotted line indicates the transition of the command torque before correction based on the accelerator operation amount. Figure 8 As indicated by the solid line in the graph of , the command torque is limited to be equal to or less than the torque upper limit value until the accelerator operation amount reaches the maximum, and the increase ratio according to the accelerator operation amount is limited so that the current flowing through the battery packs 17, 18 becomes equal to or less than the upper limit current, and the command torque is corrected to gradually increase compared with the command torque before correction. More specifically, the command torque is corrected according to the following relationship.

[0101] Command torque = command torque before correction × (current related upper limit value / maximum current related upper limit value)

[0102] The maximum current-related upper limit value is the maximum value of the current-related upper limit value and corresponds to Figure 5 and Figure 6The values ​​of the upper limit current regions I1 and I11 in the figure are shown.

[0103] Battery charging determination circuit

[0104] When the electric motorcycle 1 performs regenerative braking, the battery charging determination circuit 33 determines whether to charge the battery packs 17, 18 based on the current flowing through the battery packs 17, 18. More specifically, when the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current, the battery management units 17f, 18f close the charging switch elements 17b and 18b, so that the battery packs 17, 18 are switched to a chargeable state, and charging is thereby performed. When the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 exceeds the upper limit current, the battery management units 17f, 18f open the charging switch elements 17b and 18b, so that the battery packs 17, 18 are switched to a charge prohibited state, and charging is thereby stopped.

[0105] Control Methods

[0106] Depend on Figure 2 The control method performed by the circuit 25 shown in the figure includes drive control and regeneration control, wherein the drive control is used to drive the motor 14 by bringing the battery packs 17, 18 into a discharge state in which electric power is discharged toward the motor 14, and the regeneration control is used to charge the battery packs 17, 18 by bringing the battery packs 17, 18 into a charging state in which electric power is supplied from the motor 14.

[0107] Fig. 9 is used Figure 2 The memory 24b of the control unit 24 stores the control information for controlling the motor 14 according to the circuit 25 in FIG. Fig. 9 The flowchart shown in FIG. 1 executes the control procedure.

[0108] In step S1 , the control unit 24 acquires the potentials of the battery packs 17 , 18 transmitted from the battery attachment detection sensors 19 , 20 , and determines whether the two battery packs 17 , 18 are electrically connected to the power path 26 , or whether only one of the two battery packs 17 , 18 is electrically connected to the power path 26 .

[0109] Next, in step S2 , the control unit 24 acquires the SOCs of the battery cells 17 a , 18 a and the temperatures of the battery packs 17 , 18 transmitted from the battery management units 17 f , 18 f .

[0110] Next, in step S3, the current-related upper limit value setting circuit 30 of the control unit 24 sets the upper limit current of the current flowing through the battery packs 17 and 18 to the current-related upper limit value as described above. More specifically, when the drive control is performed, that is, when the battery packs 17 and 18 are in the discharge state, the current-related upper limit value setting circuit 30 sets the upper limit current of the current flowing through the battery packs 17 and 18 to the current-related upper limit value as described above. Figure 5 The diagram shown in FIG sets the upper limit current based on the SOC of the battery cells 17a, 18a and the temperature of the battery packs 17, 18. When the regeneration control is performed, that is, when the battery packs 17, 18 are in the charging state, the current-related upper limit value setting circuit 30 sets the upper limit current based on the SOC of the battery cells 17a, 18a and the temperature of the battery packs 17, 18. Figure 6 The diagram shown sets the upper limit current based on the SOC of the battery cells 17a, 18a and the temperature of the battery packs 17, 18. When the two battery packs 17, 18 are electrically connected to the power path 26, the minimum value of the upper limit current of the two battery packs 17, 18 is set to the current-related upper limit value. When only one of the battery packs 17, 18 is electrically connected to the power path 26, the upper limit current of the connected battery packs 17, 18 is set to the current-related upper limit value. In addition, when the switch box 22 closes one of the switch elements 28, 29 and only one of the battery packs 17, 18 is electrically connected to the inverter circuit 27 via the power path 26, the upper limit current of the connected battery packs 17, 18 is set to the current-related upper limit value.

[0111] Next, in step S4, the control unit 24 determines whether the battery packs 17, 18 are in the charge prohibited state when the drive control is performed. More specifically, in the case where the drive control is performed, that is, in the case where the battery packs 17, 18 are in the dischargeable state, when the battery packs 17, 18 are in the charge prohibited state ("Yes" (YES) in step S4), the control process proceeds to step S5, and when the battery packs 17, 18 are not in the charge prohibited state ("No" (NO) in step S4), the control process skips step S5 and proceeds to step S6.

[0112] In step S5, since the battery packs 17, 18 are in the dischargeable state and the charge prohibited state, the current-related upper limit value setting circuit 30 sets the allowable current of the discharge rectifying diodes 17c, 18c to the upper limit current of the battery packs 17, 18 for the purpose of electrically protecting the discharge rectifying diodes 17c, 18c as described above. In addition, the current-related upper limit value setting circuit 30 resets the allowable current of the discharge rectifying diodes 17c, 18c to the minimum value of the set upper limit current of the battery packs 17, 18 as the current-related upper limit value. When only one of the battery packs 17, 18 is electrically connected to the power path 26, the current-related upper limit value setting circuit 30 resets the allowable current of the discharge rectifying diodes 17c, 18c of the connected battery packs 17, 18 to the current-related upper limit value.

[0113] Next, in step S6, the control unit 24 determines whether the regeneration control is to be performed, that is, whether the battery packs 17, 18 are in a charging state with electric power supplied from the motor 14. More specifically, when the battery packs 17, 18 are in a charging state ("Yes" (YES) in step S6), the control process proceeds to step S7, and when the battery packs 17, 18 are not in a charging state ("No" (NO) in step S6), that is, when the drive control is to be performed, the control process skips steps S7, S8 and proceeds to step S9.

[0114] In step S7, the battery charging determination circuit 33 of the control unit 24 determines whether the current-related value of the battery packs 17, 18, that is, the current is greater than the current-related upper limit value, that is, the upper limit current. More specifically, when the current flowing through the battery packs 17, 18 is greater than the upper limit current ("Yes" (YES) in step S7), the control process proceeds to step S8, and when the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current ("No" (NO) in step S7), the control process skips step S8 and proceeds to step S9, that is, as described above, the battery packs 17, 18 maintain the charged state, and charging is performed by regeneration control.

[0115] In step S8, since the current flowing through the battery packs 17 and 18 is greater than the upper limit current, the battery charge determination circuit 33 transmits an electrical signal including an instruction to turn off the charging switch elements 17b and 18b to the battery management units 17f and 18f as described above. By turning off the charging switch elements 17b and 18b, the battery management units 17f and 18f switch the battery packs 17 and 18 to the charging prohibited state to cancel the charging state of the battery packs 17 and 18, and stop the charging of the battery packs 17 and 18.

[0116] Next, in step S9 , as described above, the torque upper limit value calculation circuit 31 of the control unit 24 calculates the torque upper limit value from the characteristics between the applied current and the output torque of the motor 14 based on the current-related upper limit value (ie, the upper limit current of the battery packs 17 , 18 ).

[0117] Next, in step S10 , the control unit 24 acquires the accelerator operation amount transmitted from the accelerator grip sensor 12 and the rotation speed of the motor 14 transmitted from the motor rotation speed sensor 16 .

[0118] Next, in step S11 , the command torque calculation circuit 32 of the control unit 24 calculates a command torque to be issued to the motor 14 via the motor driver 21 based on the accelerator operation amount and the rotation speed of the motor 14 as described above.

[0119] Next, in step S12, the command torque calculation circuit 32 determines whether the command torque needs to be corrected. More specifically, when the command torque exceeds the torque upper limit value ("Yes" (YES) in step S12), it is determined that the command torque needs to be corrected, and the control process proceeds to step S13, and when the command torque is equal to or less than the torque upper limit value ("No" (NO) in step S12), it is determined that the command torque does not need to be corrected, and the control process skips step S13 and proceeds to step S14.

[0120] In step S13, the command torque calculation circuit 32 corrects the command torque so that the command torque becomes equal to or less than the torque upper limit value, so as to maintain the state in which the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current as described above. In this embodiment, the corrected command torque is calculated by Figure 8 The correction command torque is calculated by the method shown in .

[0121] Next, in step S14, the control unit 24 transmits the command torque output from the motor 14 as an electrical signal to the motor driver 21. Based on the reception of the electrical signal including the command torque, the motor driver 21 controls the inverter circuit 27 to drive the motor 14 or controls the inverter circuit 27 to perform regenerative braking of the motor 14, so that the motor 14 outputs the command torque.

[0122] The control of the motor 14 including the driving control and the regeneration control is performed along the flow including step S1 to step S14.

[0123] Operation and Effect

[0124] The electric motorcycle 1 configured as described above has the following features.

[0125] The control method of the motor 14 for the electric motorcycle 1 according to this embodiment includes:

[0126] According to the vehicle state when the electric motorcycle 1 is driven by the motor 14, a current upper limit value related to the current flowing through the battery packs 17, 18 of the electric motorcycle 1 is set; and based on the accelerator operation amount input to the electric motorcycle 1 and the current-related upper limit value, a torque upper limit value of the command torque to be issued to the motor 14 to maintain a state in which the current-related value is equal to or less than the current-related upper limit value is calculated.

[0127] According to the present embodiment, the control method of the motor 14 for the electric motorcycle 1 calculates the torque upper limit value of the command torque to the motor 14 so that the current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than the current-related upper limit value. By calculating the torque upper limit value of the command torque, even when the battery packs 17, 18 with a small allowable current are installed or even when the battery packs 17, 18 without the current limiting function are installed, the battery-related components can be electrically protected. Therefore, the electric motorcycle 1 has a function of protecting the battery-related components, and various batteries and battery control circuits can be freely selected to be installed.

[0128] Since the torque upper limit value of the command torque is calculated, it is easier to reduce the influence on the driving feeling than in the case where the current of the battery packs 17 and 18 is controlled.

[0129] When the accelerator operation amount is maximum, the calculated command torque increases as the accelerator operation amount increases so that the current-related value becomes the current-related upper limit value.

[0130] According to the present embodiment, the command torque can be changed according to the accelerator operation amount. Since the current-related value related to the current flowing through the battery packs 17, 18 is controlled to be equal to or less than the current-related upper limit value until the accelerator operation amount reaches the maximum, the command torque can be increased according to the increase in the accelerator operation amount to approach the driver's operating feeling.

[0131] The command torque is calculated by the following relationship.

[0132] Command torque = command torque before correction × (current related upper limit value / maximum current related upper limit value), where

[0133] The command torque before correction is a torque based on the accelerator operation amount input by the driver, and

[0134] The maximum current-related upper limit value is a maximum value of the current-related upper limit values.

[0135] According to the present embodiment, since the command torque is reduced to be equal to or less than the torque upper limit value until the accelerator operation amount reaches the maximum value and the current related value is equal to or less than the current related upper limit value, the battery related components can be electrically protected.

[0136] The command torque is calculated based on the accelerator operation amount and the rotation speed of the motor 14 .

[0137] According to the present embodiment, since the command torque is calculated based on the accelerator operation amount and the rotation speed of the motor 14, it is possible to make the command torque different between when the vehicle is started and when the vehicle is running at a constant speed. For example, by setting the command torque in consideration of the rotation speed of the motor 14, even in a state where the rotation speed at the time of starting or the like is low, the current-related value can be prevented from exceeding the current-related upper limit value, and an appropriate starting torque can be provided to the electric motorcycle 1.

[0138] The current-related upper limit value is set based on the upper limit current allowed to flow through the battery packs 17 , 18 .

[0139] According to the present embodiment, the current-related upper limit value is set based on the upper limit current allowed to flow through the battery packs 17 and 18, so that the current flowing through the battery packs 17 and 18 is controlled to be equal to or less than the upper limit current. Therefore, the battery packs 17 and 18 are easily electrically protected.

[0140] It is also possible to perform control so that the current flowing through the battery packs 17 , 18 is equal to or less than the upper limit current by using electric power correlated with the current, temperature, or the like as the current-correlated value.

[0141] Upper limit currents are set for the battery packs 17 , 18 , and the current-related upper limit value is set based on the minimum upper limit current among the upper limit currents set for the battery packs 17 , 18 .

[0142] According to the present embodiment, the current-related upper limit value is set based on the minimum upper limit current among the upper limit currents set for the battery packs 17 and 18, so that the current flowing through the battery packs 17 and 18 is controlled to be equal to or less than the minimum upper limit current. Therefore, all the battery packs 17 and 18 are easily electrically protected.

[0143] The control method includes: drive control for driving the motor 14 by bringing the battery packs 17, 18 into a discharge state in which electric power is discharged toward the motor 14, and regenerative control for charging the battery packs 17, 18 by bringing the battery packs 17, 18 into a charge state in which electric power is supplied from the motor 14 when the electric motorcycle 1 performs regenerative braking.

[0144] The upper limit current varies depending on whether the battery packs 17 , 18 are in a discharging state or a charging state.

[0145] According to the present embodiment, the upper limit current varies depending on whether the battery packs 17, 18 are in a discharge state or a charge state, and is set to an appropriate value. Therefore, the battery packs 17, 18 are easily electrically protected even when the battery packs 17, 18 are in a discharge state or a charge state.

[0146] The regenerative control includes: charging the battery packs 17, 18 when the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current and the battery packs 17, 18 are in a charged state during regenerative braking of the electric motorcycle 1, and releasing the charged state of the battery packs 17, 18 when the current flowing through the battery packs 17, 18 exceeds the upper limit current during regenerative braking of the electric motorcycle 1.

[0147] According to the present embodiment, when the current flowing through the battery packs 17, 18 exceeds the upper limit current during regenerative braking of the electric motorcycle 1, the charged state of the battery packs 17, 18 is released. Therefore, the battery packs 17, 18 are less likely to be overcharged, and the battery packs 17, 18 are easily electrically protected.

[0148] The current-related upper limit value is set based on the upper limit current of the circuit elements included in the circuit 25 electrically connected to the battery packs 17 , 18 and the motor 14 .

[0149] According to this embodiment, the current-related upper limit value is set based on the upper limit current for electrically protecting the circuit element, so that the current flowing through the circuit element is controlled to be equal to or less than the upper limit current. Therefore, the circuit element is easily electrically protected.

[0150] The circuit 25 includes: charging switch elements 17b, 18b and discharging switch elements 17d, 18d electrically connected to the battery cells 17a, 18a; and discharging rectifier diodes 17c, 18c and charging rectifier diodes 17e, 18e electrically connected in parallel with the charging switch elements 17b, 18b.

[0151] The current-related upper limit value is set to the allowable current of the discharge rectifying diodes 17c, 18c when the charging switch elements 17b and 18b are turned off.

[0152] According to this embodiment, when the battery packs 17 and 18 are in a discharging state in which electric power is discharged toward the motor 14 and the charging switch elements 17b and 18b are disconnected, the current-related upper limit value is set to the allowable current of the discharge rectifier diodes 17c and 18c, and therefore the discharge rectifier diodes 17c and 18c are easily electrically protected.

[0153] When the battery packs 17, 18 are in a chargeable state in which current is allowed to flow from the motor 14 to the battery packs 17, 18 by closing the charging switch elements 17b and 18b, when the conditions for preventing overcharging of the battery cells 17a, 18a are met, the battery packs 17, 18 are switched to a charge prohibited state in which current is prohibited from flowing from the motor 14 to the battery packs 17, 18 because the charging switch elements 17b and 18b are disconnected.

[0154] According to the present embodiment, when the battery packs 17 and 18 are in a chargeable state, when a condition for preventing overcharging of the battery cells 17a and 18a is satisfied, the battery packs 17 and 18 are switched to a charge inhibition state, thereby preventing the battery cells 17a and 18a from being overcharged.

[0155] The control unit 24 of the motor 14 of the electric motorcycle 1 according to the present embodiment includes: a current-related upper limit value setting circuit 30 that sets a current-related upper limit value of a current-related value related to a current flowing through the battery packs 17, 18 of the electric motorcycle 1 according to a vehicle state when the electric motorcycle 1 is driven by the motor 14; and a torque upper limit value calculation circuit 31 that calculates a torque upper limit value of a command torque to be issued to the motor 14 to maintain a state in which the current-related value is equal to or less than the current-related upper limit value, based on an accelerator operation amount input to the electric motorcycle 1 and the current-related upper limit value.

[0156] According to the present embodiment, the control unit 24 of the motor 14 of the electric motorcycle 1 calculates the torque upper limit value of the command torque to the motor 14 so that the current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than the current-related upper limit value. By calculating the torque upper limit value of the command torque, even when the battery packs 17, 18 with a small allowable current are installed or even when the battery packs 17, 18 without the current limiting function are installed, the battery-related components can be electrically protected. Therefore, the electric motorcycle 1 has a function of protecting the battery-related components, and various batteries and battery control circuits can be freely selected to be installed.

[0157] Since the torque upper limit value of the command torque is calculated, it is easy to reduce the influence on the driving feeling compared with the case where the current of the battery packs 17 and 18 is controlled.

[0158] The electric motorcycle 1 of the present embodiment includes a control unit 24 .

[0159] According to the present embodiment, when the electric motorcycle 1 is driven, the torque upper limit value of the command torque to the motor 14 is calculated so that the current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than the current-related upper limit value. By calculating the torque upper limit value of the command torque, even when the battery packs 17, 18 with a small allowable current are installed or even when the battery packs 17, 18 without the current limiting function are installed, the battery-related components can be electrically protected. Therefore, the electric motorcycle 1 has a function of protecting the battery-related components, and various batteries and battery control circuits can be freely selected to be installed.

[0160] Since the torque upper limit value of the command torque is calculated, it is easy to reduce the influence on the driving feeling compared to the case where the current of the battery packs 17 and 18 is controlled. For example, when the command torque is equal to or less than the torque upper limit value, the influence on the driving feeling is easily reduced by issuing the command torque to the motor 14 without reducing the command torque. In addition, when the command torque is greater than the torque upper limit value, the command torque is corrected to be reduced, and the corrected command torque is issued to the motor 14 so that the battery-related components can be electrically protected. In particular, according to Figure 8 With the method of correcting the command torque shown in , the command torque is less likely to change suddenly near the torque upper limit value, and the influence on the driving feeling is easily reduced.

[0161] Other embodiments

[0162] The present disclosure is not limited to the configurations of the above-described embodiments, and various modifications may be made.

[0163] In the above-mentioned embodiment, the electric vehicle 1 is an electric motorcycle, and may be a three-wheeled vehicle or a four-wheeled vehicle. Preferably, the present invention can be suitably used for a straddle-type vehicle that is lighter than a four-wheeled vehicle in which the right and left wheels are arranged at intervals in the vehicle width direction and which has a large influence on the driving feeling. A straddle-type vehicle means a type of vehicle in which a driver sits on a straddle-type seat so that the driver's legs are positioned on the left and right sides of the vehicle in a riding posture.

[0164] In the above embodiment, the two battery packs 17, 18 are connected in parallel, and may be connected in series. A single battery pack may be electrically connected to the power path.

[0165] In the above-described embodiment, the two battery packs 17 , 18 are attachable to and detachable from the main body 2 , and may be non-detachably mounted on the main body 2 .

[0166] In the above embodiments, the upper limit current of the battery packs 17, 18 is set to a current-related upper limit value, but a value related to the current flowing through the battery packs 17, 18 (for example, an upper limit value of electric power, temperature, or the like that increases as the current increases) can be set as a current-related upper limit value.

[0167] In the above-described embodiment, when the battery packs 17, 18 are in the charge prohibited state and in the dischargeable state, the current-related upper limit value setting circuit 30 sets the allowable current of the discharge rectifying diodes 17c, 18c to the upper limit current of the battery packs 17, 18 so as to electrically protect the discharge rectifying diodes 17c, 18c. However, when the battery packs 17, 18 are in the discharge prohibited state and in the chargeable state, the current-related upper limit value setting circuit 30 may set the allowable current of the charge rectifying diodes 17e and 18e to the upper limit current of the battery packs 17, 18 so as to protect the charge rectifying diodes 17e and 18e from excessive discharge of the battery packs 17, 18.

[0168] The present disclosure can be applied not only to electric vehicles but also to hybrid vehicles having a mode in which the vehicle is driven by a motor. A vehicle structure, that is, the layout of components such as a battery pack or a motor, may be different from the arrangement relationship disclosed in the above-mentioned embodiment. For example, the motor may be an in-wheel motor, and the battery pack may be installed on a device other than the main body.

[0169] In the above-described embodiment, the electric motorcycle includes the circuit 25, and may include a circuit having another configuration. For example, the control unit may have some or all of the functions of the battery management unit. Instead of the switch box, the control unit may have the function of the switch box and control the electrical connection between the battery pack and the inverter circuit via the power path by switching the switch element open and closed. In addition, the switch box may have a part of the functions of the control unit.

[0170] A first aspect of the present disclosure provides a control method for a motor of an electric vehicle. The method includes: setting a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by the motor; and calculating a torque upper limit value of a command torque for commanding the motor to maintain a state in which the current-related value is equal to or less than the current-related upper limit value based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value.

[0171] A second aspect of the present disclosure provides the control method according to the first aspect. When the accelerator operation amount is maximum, the command torque is calculated to increase as the accelerator operation amount increases so that the current related value becomes the current related upper limit value.

[0172] A third aspect of the present disclosure provides a control method according to the second aspect.

[0173] The command torque is calculated by the following relationship.

[0174] Command torque = command torque before correction × (current related upper limit value / maximum current related upper limit value), where

[0175] The command torque before correction is a torque based on the accelerator operation amount input by the driver, and

[0176] The maximum current related upper limit value is the maximum value of the current related upper limit value

[0177] A fourth aspect of the present disclosure provides the control method according to the first aspect or the second aspect. The command torque is calculated based on the accelerator operation amount and the rotation speed of the motor.

[0178] A fifth aspect of the present disclosure provides the control method according to any one of the first to fourth aspects. The current-related upper limit value is set based on an upper limit current allowed to flow through the battery.

[0179] A sixth aspect of the present disclosure provides a control method according to any one of the first to fifth aspects. When the battery includes a plurality of batteries electrically connected in parallel, a current-related upper limit value is set for each of the plurality of batteries. The current-related upper limit value is set based on the minimum current-related upper limit value among the current-related upper limit values ​​set for each of the plurality of batteries.

[0180] A seventh aspect of the present disclosure provides a control method according to any one of the first to sixth aspects. The control method further includes: a drive control for driving the motor by bringing the battery into a discharge state in which electric power is discharged toward the motor; and a regeneration control for charging the battery by bringing the battery into a charge state in which electric power is supplied from the motor during regenerative braking of the electric vehicle. The current-related upper limit value varies depending on whether the battery is in a discharge state or a charge state.

[0181] The eighth aspect of the present disclosure provides a control method according to the seventh aspect. The regenerative control includes: during regenerative braking of the electric vehicle, charging the battery by bringing the battery into a charging state when the current-related value is equal to or less than the current-related upper limit value; and during regenerative braking of the electric vehicle, releasing the charging state of the battery when the current-related value exceeds the current-related upper limit value.

[0182] A ninth aspect of the present disclosure provides the control method according to any one of the first to eighth aspects. The current-related upper limit value is set based on an upper limit current of a circuit element included in a circuit electrically connected to the battery and the motor.

[0183] The tenth aspect of the present disclosure provides a control method according to the ninth aspect. The circuit includes: a switch element electrically connected to a battery; and a diode electrically connected to the switch element in parallel. The current-related upper limit value is set to an allowable current of the diode when the switch element is disconnected.

[0184] The eleventh aspect of the present disclosure provides a control method according to the tenth aspect. When the battery is in a charging state in which a current is allowed to flow from a motor to the battery by closing a switch element, when a condition for preventing overcharging of the battery is met, the battery is switched to a charging prohibition state in which a current is prohibited from flowing from a motor to the battery by opening the switch element.

[0185] A twelfth aspect of the present disclosure provides a control device for a motor of an electric vehicle. The control device includes: a current-related upper limit value setting unit configured to set a current-related upper limit value related to a current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by the motor; and a torque upper limit value calculation unit configured to calculate a torque upper limit value of a command torque for commanding the motor to maintain a state in which the current-related value is equal to or less than the current-related upper limit value based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value.

[0186] A thirteenth aspect of the present disclosure provides an electric vehicle including the control device according to the twelfth aspect.

Claims

1. A method for controlling a motor of an electric vehicle, the method comprising: setting a current-related upper limit value of a current-related value related to current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by a motor; as well as Based on an accelerator operation amount input to the electric vehicle and the current related upper limit value, a torque upper limit value of a command torque for commanding a motor to maintain a state in which the current related value is equal to or less than the current related upper limit value is calculated.

2. The control method according to claim 1, wherein: When the accelerator operation amount is maximum, the command torque is calculated to increase as the accelerator operation amount increases so that the current related value becomes the current related upper limit value.

3. The control method according to claim 2, wherein: The command torque is calculated by the following relationship, Command torque = command torque before correction × (current related upper limit value / maximum current related upper limit value), where, The command torque before correction is a torque based on the accelerator operation amount input by the driver, and The maximum current-related upper limit value is a maximum value of the current-related upper limit values.

4. The control method according to claim 1 or 2, wherein: The command torque is calculated based on the accelerator operation amount and the rotation speed of the motor.

5. The control method according to claim 1 or 2, wherein: The current-related upper limit value is set based on an upper limit current allowed to flow through the battery.

6. The control method according to claim 1 or 2, wherein: When the battery comprises a plurality of batteries electrically connected in parallel, setting the current-related upper limit value for each of the plurality of batteries, and The current-related upper limit value is set based on a minimum current-related upper limit value among the current-related upper limit values ​​set for each of the plurality of batteries.

7. The control method according to claim 1 or 2, further comprising: a drive control for driving the motor by bringing the battery into a discharge state in which electric power is discharged toward the motor; as well as regenerative control for charging the battery by bringing the battery into a charging state in which electric power is supplied from the motor during regenerative braking of the electric vehicle, wherein The current-related upper limit value varies depending on whether the battery is in the discharge state or the charge state.

8. The control method according to claim 7, wherein: The regeneration control includes: charging the battery by bringing the battery into the charging state when the current-related value is equal to or less than the current-related upper limit value during regenerative braking of the electric vehicle; and During regenerative braking of the electric vehicle, the state of charge of the battery is released when the current-related value exceeds the current-related upper limit value.

9. The control method according to claim 1 or 2, wherein: The current-related upper limit value is set based on an upper limit current of a circuit element included in a circuit electrically connected to the battery and the motor.

10. The control method according to claim 9, wherein: The circuit comprises: a switching element electrically connected to the battery; and a diode electrically connected in parallel to the switching element, and The current-related upper limit value is set to an allowable current of the diode when the switching element is turned off.

11. The control method according to claim 10, wherein: When the battery is in a chargeable state in which the current is allowed to flow from the motor to the battery by closing the switching element, when a condition for preventing overcharging of the battery is met, the battery is switched to a charge prohibited state in which the current is prohibited from flowing from the motor to the battery by opening the switching element.

12. A control device for a motor of an electric vehicle, the control device comprising: a current-related upper limit value setting unit configured to set a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle according to a vehicle state when the electric vehicle is driven by the motor; as well as A torque upper limit value calculation unit is configured to calculate a torque upper limit value of a command torque for commanding the motor to maintain a state in which the current related value is equal to or less than the current related upper limit value based on an accelerator operation amount input to the electric vehicle and the current related upper limit value.

13. An electric vehicle comprising the control device according to claim 12.

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