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

Abstract

To provide a control method capable of electrically protecting a battery-related component and expanding options for a battery and a battery control circuit to be mounted.SOLUTION: A control method for a motor 14 of an electric two-wheeled vehicle 1 includes: setting a current-related upper limit value of a current-related value related to a current flowing through battery packs 17 and 18 of the electric two-wheeled vehicle 1 according to a vehicle state when the electric two-wheeled vehicle 1 is driven by the motor 14; and calculating a torque upper limit value of command torque to be issued to the motor 14 so as to maintain a state where the current-related value is equal to or less than the current-related upper limit value, on the basis of an accelerator operation amount input to the electric two-wheeled vehicle 1 and the current-related upper limit value.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] Patent Document 1 discloses a control method and control device for a motor of an electric vehicle, and an electric vehicle equipped with the same. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-233396 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, an upper limit value for the discharge power of a battery is set, and the discharge power of the battery is suppressed to be equal to or less than the upper limit value.

[0005] In order to suppress the discharge power of the battery, it is necessary to add an additional function or component to the battery or the battery control circuit, such as incorporating a current limiting function in the battery or the battery control circuit electrically connected to the battery. A typical electric vehicle requires a function to suppress the discharge power of the battery in order to electrically protect battery-related components. Therefore, it is difficult for a typical electric vehicle to be equipped with a variety of batteries and battery control circuits that can be freely selected.

[0006] Therefore, an object of the present disclosure is to provide a control method that electrically protects battery-related components and can expand the options for batteries and battery control circuits to be mounted. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, when an electric vehicle is driven by a motor, a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle is set in accordance with a vehicle state; The present invention provides a method for controlling a motor of an electric vehicle, comprising: calculating a torque upper limit value of a command torque to be commanded to the motor based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value.

[0008] According to the present disclosure, a method for controlling a motor of an electric vehicle calculates a torque upper limit value of a command torque to the motor such 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, even if a battery with a small allowable current is mounted, or even if a battery and a battery control circuit without a current limiting function are mounted, battery-related components can be electrically protected. Thus, the electric vehicle is provided with a function for protecting battery-related components, and various batteries and battery control circuits can be freely selected and mounted. Effect of the Invention

[0009] Therefore, according to the method for controlling a motor of an electric vehicle according to the present disclosure, it is possible to electrically protect battery-related components and expand the options for batteries and battery control circuits to be mounted. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of an electric vehicle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a circuit diagram of the electric vehicle of FIG. [Diagram 3] FIG. 3 is a circuit diagram of a battery included in the circuit of FIG. 2. [Figure 4] FIG. 3 is a block diagram showing a system for controlling a motor included in the circuit of FIG. 2. [Diagram 5]5 is a map of upper limit current when the battery is discharging, used by the current-related upper limit setting circuit of FIG. 4; [Figure 6] 5 is a map of upper limit currents used by the current-related upper limit setting circuit of FIG. 4 when the battery is charging. [Figure 7] 5 is a graph showing an example of a command torque corrected by the command torque calculation circuit of FIG. 4; [Figure 8] 5 is a graph showing another embodiment of the command torque corrected by the command torque calculation circuit of FIG. 4. [Figure 9] 3 is a flowchart of motor control performed using the circuit of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0012] [Electric vehicle configuration] 1 is a side view of an electric vehicle (hereinafter referred to as an "electric two-wheeler") 1 according to an embodiment of the present disclosure. In this embodiment, directions such as forward, backward, rightward, and leftward are each directions seen from the perspective of a rider riding the electric two-wheeler 1.

[0013] The electric two-wheeler 1 includes a main body 2 of the electric two-wheeler 1, a front wheel 3 disposed in front of the main body 2, and a rear wheel 4 disposed behind the main body 2.

[0014] The front wheel 3 is rotatably supported at the lower part of a front fork 5 extending in the vertical direction. The front fork 5 is supported by a steering shaft 8 via an upper bracket 6 provided at an upper end of the front fork 5 and a lower bracket 7 provided below the upper bracket 6. The steering shaft 8 is rotatably supported by a head pipe 9 attached to the main body 2.

[0015] A handlebar 10 extending laterally is attached to the upper bracket 6. When the rider swings the handlebar 10 laterally, the front wheel 3 is steered about the steering shaft 8 as a rotation axis.

[0016] Accelerator grips 11 are rotatably attached to both sides of the handlebar 10. When the rider wants to start or accelerate the electric motorcycle 1, he or she rotates the accelerator grip 11 to request starting or accelerating. The accelerator grip 11 has an accelerator grip sensor 12 that is electrically connected to a control unit 24, which will be described later. The accelerator grip sensor 12 detects the amount of accelerator operation input by rotating the accelerator grip 11, and transmits a signal including the amount of accelerator operation to the control unit 24.

[0017] A drive system component 13 for driving the rear wheel 4 is disposed on the inner side of the main body 2 in the vehicle width direction in order to run the electric two-wheeled vehicle 1. The drive system component 13 has a motor 14 and a power transmission component 15. The motor 14 generates a driving force when supplied with electric power. In this embodiment, the motor 14 is a three-phase AC motor. The power transmission component 15 connects the output shaft of the motor 14 to the rear wheel, which is a driving wheel, so that power can be transmitted. The power transmission component 15 includes, for example, a splot and a chain, and transmits the driving force of the motor 14 to the rear wheel 4. The electric two-wheeled vehicle 1 also includes a motor rotation speed sensor 16, which is electrically connected to a control unit 24 (described later), in the vicinity of 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.

[0018] Two chargeable and dischargeable battery packs 17, 18 that supply power to the motor 14 are arranged on the inside of the main body 2 in the vehicle width direction. Each of the two battery packs 17, 18 is detachable from the main body 2. Each battery pack is configured to be chargeable by an external charging device when removed from the main body 2. The charged battery pack is attached to the main body 2 by the user. In this embodiment, two battery packs 17, 18 are arranged, but one or three or more battery packs may be arranged.

[0019] Battery attachment detection sensors 19, 20 that detect whether the two battery packs 17, 18 are attached are disposed on the inside of the main 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 main body 2 and transmit a signal including whether the two battery packs 17, 18 are attached to the main body 2 to a control unit 24 described later.

[0020] A motor driver 21 is disposed on the inside in the vehicle width direction of the main body 2. The motor driver 21 is electrically connected to the motor 14, and controls the driving torque output by the motor 14 by controlling the power supplied from the battery packs 17 and 18 to the motor 14.

[0021] A switch box 22 is disposed on the inside in the vehicle width direction of the main body 2. The switch box 22 controls the electrical connection between the two battery packs 17, 18 and the motor 14 so as to enable selection between a parallel connection state in which both of the two battery packs 17, 18 supply power to the motor 14, and an independent connection state in which either of the battery packs 17, 18 supplies power to the motor 14.

[0022] A wheel speed sensor 23 that detects the rotation speed of the front wheel 3 is disposed 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, which will be described later.

[0023] A control unit 24 is disposed on the inside of the main 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 RPM 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, in response to signals transmitted from the accelerator grip sensor 12 and the like, and has a processor 24a that performs control processing, a memory 24b that stores a control program, and an input / output interface 24c that transmits and receives signals to and from the above-mentioned electrical components.

[0024] In this embodiment, the control unit 24 is electrically connected to the two battery packs 17, 18 and performs control to permit charging and discharging. On the other hand, a battery control device that controls charging and discharging of the two battery packs 17, 18 other than the control unit 24 may be disposed on the inner side of the main body 2 in the vehicle width direction.

[0025] [Electric circuit configuration] FIG. 2 is a circuit diagram of the electric motorcycle 1 of FIG. 1, and particularly shows an electrical circuit 25 that electrically connects the motor 14, the two battery packs 17, 18, the motor driver 21, the switch box 22, and the control unit 24.

[0026] In this embodiment, the electric circuit 25 connects the two battery packs 17, 18 in parallel with each other, and has an electric power path 26 that 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 path that supplies electric power from the two battery packs 17, 18 to the motor 14, and also supplies electric power from the motor 14 to the two battery packs 17, 18.

[0027] The electric circuit 25 has an inverter circuit 27 that adjusts the frequency of AC power supplied from the two battery packs 17, 18 to the motor 14 or supplied from the motor 14 to the two battery packs 17, 18. The inverter circuit 27 has switching elements 27a to 27f that are three-phase bridge-connected to each other. Each of the switching elements 27a to 27f is a MOSFET, and the gate is electrically connected to the motor driver 21.

[0028] The switching elements 27a to 27f have a characteristic that when a voltage is applied to the gate, they close to provide electrical continuity between the source and drain, and when no voltage is applied to the gate, they open to provide no electrical continuity between the source and drain. Therefore, the motor driver 21 switches between opening and closing the switching elements 27a to 27f by controlling the voltage applied to the gates 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 supplied from the motor 14 to the two battery packs 17, 18.

[0029] The motor driver 21 is an integrated circuit that is electrically connected to the control unit 24, and controls the inverter circuit 27 to drive the motor 14 in accordance with an electrical signal sent from the control unit 24, the electrical signal including an instruction to output a command torque to the motor 14.

[0030] As described above, the motor driver 21 is configured to switch the opening and closing of the switching elements 27a to 27f to supply power from the two battery packs 17, 18 to the motor 14 when the electric motorcycle 1 is traveling, thereby driving the motor 14. The motor driver 21 is also configured to switch the opening and closing of the switching elements 27a to 27f to supply power from the motor 14 to the two battery packs 17, 18 when the electric motorcycle 1 is performing regenerative braking, thereby charging the two battery packs 17, 18.

[0031] The two battery packs 17, 18 each have a battery management unit 17f, 18f (described later) that is electrically connected to the control unit 24. The battery management units 17f, 18f control the battery packs 17, 18 to permit or prohibit discharging or charging, and obtain information such as the temperature and SOC (charging rate) of the battery packs 17, 18 and transmit the information to the control unit 24 as an electrical signal.

[0032] The electric circuit 25 has the battery attachment detection sensors 19, 20. The battery attachment detection sensors 19, 20 are electrically connected to the positive and negative poles of the battery packs 17, 18 so as to detect the potentials of the battery packs 17, 18, respectively. The battery attachment detection sensors 19, 20 are also electrically connected to the control unit 24. When the battery attachment detection sensors 19, 20 detect the potentials of the battery packs 17, 18, respectively, they transmit an electric signal including the potentials 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 detection of the potentials of the battery packs 17, 18. When the battery attachment detection sensors 19, 20 do not detect the potentials of the battery packs 17, 18, respectively, they transmit an electric signal including the non-detection of the potentials of the battery packs 17, 18 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 potentials of the battery packs 17, 18 are not detected.

[0033] 2, 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 power path 26 based on the potentials of the battery packs 17, 18 transmitted from the battery attachment detection sensors 19, 20.

[0034] The electric circuit 25 has switching elements 28, 29 electrically connected to the battery packs 17, 18 and the power path 26, respectively. The switching elements 28, 29 are each electrically connected to the switch box 22. The switching elements 28, 29 each switch between conduction and cut-off between the battery packs 17, 18 and the power path 26 in accordance with an electrical signal including an instruction for conduction and cut-off transmitted from the switch box 22. In this embodiment, the switching elements 28, 29 are each a relay element, but may also be a MOSFET.

[0035] The switch box 22 is an integrated circuit that is electrically connected to the control unit 24 and operates switching elements 28, 29 in accordance with an electrical signal sent from the control unit 24, the switching element 28, 29 switching between conduction and cut-off between the two battery packs 17, 18 and the power path 26, via the power path 26.

[0036] [Battery pack configuration] Fig. 3 is a circuit diagram of the battery pack 17 included in the electric circuit 25 of Fig. 2. In this embodiment, the battery pack 17 has a general configuration that does not include special specifications. Also, the battery pack 18 has the same configuration as the battery pack 17, so a description thereof will be omitted.

[0037] The battery pack 17 has a battery cell 17a that charges and discharges power to be supplied to the motor 14. In this embodiment, the battery cell 17a is composed of a plurality of battery cells, but may be composed of a single battery cell.

[0038] In this embodiment, the battery pack 17 has a charging switching element 17b electrically connected to the battery cell 17a, a discharging rectifier diode 17c electrically connected in parallel to the charging switching element 17b, a discharging switching element 17d electrically connected to the battery cell 17a via the charging switching element 17b and the discharging rectifier diode 17c, and a charging rectifier diode 17e electrically connected in parallel to the discharging switching element 17d.

[0039] The discharge-time rectifier diode 17c allows a current to flow from the battery cell 17a toward the inverter circuit 27 and prevents a current from flowing from the inverter circuit 27 toward the battery cell 17a. The charge-time rectifier diode 17e allows a current to flow from the inverter circuit 27 toward the battery cell 17a and prevents a current from flowing from the battery cell 17a toward the inverter circuit 27.

[0040] The battery pack 17 has a battery management unit 17f electrically connected to the charging switching element 17b and the discharging switching element 17d. The battery management unit 17f switches the opening and closing of the charging switching element 17b and the discharging switching element 17d to control the discharging or charging of the battery pack 17 to be permitted or prohibited, and is electrically connected to the control unit 24 to receive an electrical signal including an instruction to permit or prohibit discharging or charging of the battery pack 17, and to transmit an electrical signal including information such as the temperature and SOC (charging rate) of the battery pack 17 and the current flowing through the battery cell 17a.

[0041] In this embodiment, the charging switching element 17b and the discharging switching element 17d are each a MOSFET, and the gates are electrically connected to the battery management unit 17f, but they may be other relay elements.

[0042] The charging switching element 17b and the discharging switching element 17d have a characteristic that when a voltage is applied to the gate, they close to conduct between the source and the drain, and when no voltage is applied to the gate, they open to prevent conduction between the source and the drain. Therefore, the battery management unit 17f selectively switches between a chargeable state in which a current is permitted to flow from the inverter circuit 27 to the battery cell 17a and a charge-prohibited state in which a current is prohibited from flowing from the inverter circuit 27 to the battery cell 17a by controlling the voltage applied to the gate of the charging switching element 17b. More specifically, the battery management unit 17f switches the battery pack 17 to a chargeable state by closing the charging switching element 17b. Also, the battery management unit 17f switches the battery pack 17 to a charge-prohibited state by opening the charging switching element 17b.

[0043] Also, the battery management unit 17f selectively switches between a dischargeable state in which a current is permitted to flow from the battery cell 17a toward the inverter circuit 27 and a discharge-prohibited state in which a current is prohibited from flowing from the battery cell 17a toward the inverter circuit 27, by controlling the voltage applied to the gate of the discharge switching element 17d. More specifically, the battery management unit 17f switches the battery pack 17 to a dischargeable state by closing the discharge switching element 17d. Also, the battery management unit 17f switches the battery pack 17 to a discharge-prohibited state by opening the discharge switching element 17d.

[0044] The battery management unit 17f may switch the battery pack 17 to a chargeable state and a dischargeable state by closing both the charging switching element 17b and the discharging switching element 17d. The battery management unit 17f may also switch the battery pack 17 to a charge-prohibited state and a discharge-prohibited state by opening both the charging switching element 17b and the discharging switching element 17d.

[0045] The battery management unit 17f is an integrated circuit that switches the battery pack 17 between a dischargeable state, a discharge-prohibited state, a chargeable state, and a charge-prohibited state by controlling the voltage applied to the gates of the charging switching element 17b and the discharging switching element 17d.

[0046] When the SOC of the battery cell 17a is close to 100%, the battery cell 17a may deteriorate. Therefore, when the battery management unit 17f determines that the SOC of the battery cell 17a is close to 100%, it opens the charging switching element 17b to switch the battery pack 17 to a charging prohibited state in order to suppress deterioration of the battery cell 17a. When the battery management unit 17f determines via a temperature sensor 17h (described later) that the temperature of the battery pack 17 has reached a temperature condition under which charging should be prohibited, it similarly opens the charging switching element 17b to switch the battery pack 17 to a charging prohibited state in order to suppress deterioration of the battery cell 17a. Furthermore, when the electric motorcycle 1 is traveling, the battery management unit 17f may open the charging switching element 17b to switch the battery pack 17 to a charging prohibited state in order to prevent unintended charging.

[0047] The discharge rectifier diode 17c and the charge rectifier diode 17e have allowable currents that are upper limits of the currents that flow through the discharge rectifier diode 17c and the charge rectifier diode 17e, respectively. As described above, when the battery pack 17 is in a charge-prohibited state and in a dischargeable state, that is, when the charge switching element 17b is open and the discharge switching element 17d is closed, a large current is likely to flow through the discharge rectifier diode 17c when a current flows from the battery cell 17a toward the inverter circuit 27. Therefore, the current that flows through the discharge rectifier diode 17c may exceed the allowable current. If the current that flows through the discharge rectifier diode 17c exceeds the allowable current, the discharge rectifier diode 17c may be damaged.

[0048] The battery pack 17 includes a potential measuring 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 measuring circuit 17i that measures the current flowing through the battery cell 17a.

[0049] The potential measuring 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.

[0050] 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.

[0051] The current measuring circuit 17i is electrically connected to the battery cell 17a and the battery management unit 17f via the charging switching element 17b, the discharging rectifier diode 17c, the discharging switching element 17d, and the charging rectifier diode 17e, and transmits a signal including the measured current to the battery management unit 17f.

[0052] 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 to the control unit 24 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 17a.

[0053] In this embodiment, when there is an abnormality such as a short circuit or a disconnection in the circuit in each battery pack 17, 18, the battery management units 17f, 18f transmit an electrical signal including error information to the control unit 24. When the control unit 24 receives an electrical signal including the error information from either of the battery management units 17f, 18f, the control unit 24 opens the charging switching elements 17b, 18b and the discharging switching elements 17d, 18d via the battery management units 17f, 18f, respectively, to switch the abnormal battery pack 17, 18 to a discharge-prohibited state and a charge-prohibited state.

[0054] [Switch box configuration] In the embodiment shown in FIG. 2, the switch box 22 operates the switching elements 28, 29 based on an electrical signal sent from the control unit 24 to switch between connecting the two battery packs 17, 18 in parallel to the power path 26, or connecting only one of the two battery packs 17, 18 to the power path 26.

[0055] If the potential difference between the battery cells 17a, 18a is equal to or less than a predetermined threshold based on the potentials of the battery cells 17a, 18a contained 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 two battery packs 17, 18 in parallel to the switch box 22. By receiving the electrical signal including an instruction to connect the two battery packs 17, 18 in parallel from the control unit 24, the switch box 22 closes the switching elements 28, 29, respectively, and connects the two battery packs 17, 18 in parallel to the inverter circuit 27 via the power path 26. By electrically connecting the two battery packs 17, 18 in parallel to the inverter circuit 27 via the power path 26, the motor 14 is driven by power supplied from the two battery packs 17, 18 when the electric motorcycle 1 travels, and the two battery packs 17, 18 are charged by power supplied from the motor 14 when the electric motorcycle 1 performs regenerative braking.

[0056] When the electric motorcycle 1 is traveling, if the potential difference between the battery cells 17a, 18a is greater than a predetermined threshold based on the potentials of the battery cells 17a, 18a contained in the electrical signals transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electrical signal to the switch box 22 including an instruction to connect the battery pack having the greater potential of the two battery packs 17, 18. By receiving an electrical signal including an instruction to connect the battery pack having the greater potential of the two battery packs 17, 18 from the control unit 24, the switch box 22 closes one of the switching elements 28, 29 to connect the battery pack having the greater potential of the two battery packs 17, 18 to the inverter circuit 27 via the power path 26. By electrically connecting one of the battery packs 17, 18 to the inverter circuit 27 via the power path 26, the motor 14 is supplied with power from one of the battery packs 17, 18 to drive the electric motorcycle 1 when the electric motorcycle 1 is traveling.

[0057] When the electric motorcycle 1 performs regenerative braking, if the potential difference between the battery cells 17a, 18a is greater than a predetermined threshold based on the potentials of the battery cells 17a, 18a contained 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 pack having the lower potential of the two battery packs 17, 18 to the switch box 22. By receiving the electrical signal including an instruction to connect the battery pack having the lower potential of the two battery packs 17, 18 from the control unit 24, the switch box 22 closes one of the switching elements 28, 29 to connect the battery pack having the lower potential of the two battery packs 17, 18 to the inverter circuit 27 via the power path 26. By electrically connecting one of the battery packs 17, 18 to the inverter circuit 27 via the power path 26, one of the battery packs 17, 18 is supplied with power from the motor 14 and charged when the electric motorcycle 1 performs regenerative braking.

[0058] Even when the motor 14 is driven by power supplied from one of the battery packs 17, 18, or when one of the battery packs 17, 18 is charged by power supplied from the motor 14, if the control unit 24 determines that the potential difference between the battery cells 17a, 18a has become equal to or less than a predetermined threshold based on the potentials of the battery cells 17a, 18a contained in the electrical signals transmitted from the battery management units 17f, 18f, the control unit 24 transmits an electrical signal including an instruction to switch from a state in which only one of the two battery packs 17, 18 is connected to a state in which the two battery packs 17, 18 are electrically connected in parallel to the switch box 22. By receiving an electrical signal including an instruction to switch from a state in which only one of the two battery packs 17, 18 is connected to a state in which the two battery packs 17, 18 are electrically connected in parallel from 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 switching elements 28, 29, respectively, and electrically connects the two battery packs 17, 18 in parallel to the inverter circuit 27 via the power path 26.

[0059] [Control unit configuration] FIG. 4 is a block diagram showing a system for controlling the motor 14 included in the electric circuit 25 of FIG. 2, and in particular shows a control circuit included in the processor 24a of the control unit 24.

[0060] The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general purpose processors, application specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. Processors include transistors and other circuits and are considered to be circuitry or processing circuitry. A processor may be a programmed processor that executes a program stored in a memory. In this specification, a circuitry, unit, or means is hardware that is programmed to perform or executes the described functions. The hardware may be any hardware disclosed in this specification or any hardware that is programmed to perform or is known to perform the described functions. When the hardware is a processor, which is considered to be a type of circuitry, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0061] The processor 21 a includes a current-related upper limit setting circuit 30 , a torque upper limit calculation circuit 31 , a command torque calculation circuit 32 , and a battery charging determination circuit 33 .

[0062] The current-related upper limit setting circuit 30 sets an upper limit current for the battery packs 17, 18 based on a signal including the SOC of the battery cells 17a, 18a and the temperatures of the battery packs 17, 18 transmitted from the battery management units 17f, 18f, and sets a current-related upper limit value for a current-related value such as power or temperature related to the current flowing through the battery packs 17, 18 based on the upper limit current.

[0063] In this embodiment, the memory 24b of the control unit 24 stores a map of upper limit current with respect to the SOC and temperature of the battery pack, which will be described later. The current-related upper limit value setting circuit 30 uses the map to set the upper limit current of the battery packs 17, 18, and sets a current-related upper limit value of a current-related value, such as power or temperature, related to the current flowing through the battery packs 17, 18, based on the upper limit current. The memory 24b of the control unit 24 may also store an arithmetic expression for calculating the upper limit current based on the SOC and temperature of the battery packs, instead of the map. In this case, the current-related upper limit value setting circuit 30 uses the arithmetic expression to set the upper limit current of the battery packs 17, 18, and sets a current-related upper limit value of a current-related value, such as power or temperature, related to the current flowing through the battery packs 17, 18, based on the upper limit current.

[0064] The torque upper limit calculation circuit 31 calculates a torque upper limit of a command torque to be issued to the motor 14 via the motor driver 21, based on a signal including the accelerator operation amount transmitted from the accelerator grip sensor 12 and the current-related upper limit value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value. More specifically, the torque upper limit calculation circuit 31 calculates the torque upper limit from the characteristics between the applied current and output torque of the motor 14, based on the upper limit current related to the current-related upper limit value.

[0065] 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, the command torque is calculated as a value equal to or less than the torque upper limit value based on the accelerator operation amount and the rotation speed of the motor 14 so that the current-related value is equal to or less than the current-related upper limit value. Furthermore, when the accelerator operation amount is at a maximum, the command torque is calculated so that it increases in response to an increase in the accelerator operation amount so that the current-related value becomes the current-related upper limit value, and is suppressed to be equal to or less than the torque upper limit value.

[0066] When the electric motorcycle 1 performs regenerative braking, the battery charging determination circuit 33 determines whether or not to charge the battery packs 17, 18 according to 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 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 charging prohibited state and charging is stopped.

[0067] The memory 24b of the control unit 24 stores processing programs 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 charging determination circuit 33 described above.

[0068] The processor 24a realizes each of 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 by executing processing programs for executing each of 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, which are stored in the memory 21b.

[0069] In this embodiment, the processor 24a 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 individually as an integrated circuit, but it may also 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.

[0070] [Current-related upper limit setting circuit] In this embodiment, the current-related upper limit setting circuit 30 sets an upper limit current of the current flowing through the battery packs 17, 18 as the current-related upper limit value.

[0071] The current-related upper limit setting circuit 30 sets an upper limit current for each of the battery packs 17, 18 based on an electrical signal including the SOC of the battery cells 17a, 18a and the temperatures of the battery packs 17, 18 transmitted from the battery management units 17f, 18f, and sets the smallest upper limit current among the upper limit currents set for each of the battery packs 17, 18 as the current-related upper limit value.

[0072] The upper limit current of the battery packs 17, 18 varies depending on whether the battery packs 17, 18 are in a discharged state or a charged state. More specifically, when the battery packs 17, 18 are in a discharged state, the upper limit current of the battery packs 17, 18 is set to a value larger than that when the battery packs 17, 18 are in a charged state so that the motor 14 can output a sufficiently large torque. Also, when the battery packs 17, 18 are in a charged state, the upper limit current of the battery packs 17, 18 is set to a value smaller than that when the battery packs 17, 18 are in a discharged state in order to electrically protect the battery packs 17, 18.

[0073] Fig. 5 is a map of the upper limit current when the battery packs 17, 18 are in a discharging state, used by the current-related upper limit setting circuit 30 in Fig. 4, 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. In the map in Fig. 5, upper limit current regions I1, I2, and I3 corresponding to the temperature and SOC of the battery packs 17, 18 are defined. The magnitudes of the current values ​​[A] in the upper limit current regions I1, I2, and I3 have a relationship of I1>I2>I3.

[0074] The map of Fig. 5 is stored in the memory 24b of the control unit 24. The current-related upper limit setting circuit 30 uses the map of Fig. 5 to set upper limit currents for the corresponding regions I1, I2, I3 for each of the battery packs 17, 18 based on the temperatures and SOC of the battery packs 17, 18, and sets the minimum value of the upper limit currents of the battery packs 17, 18 as the current-related upper limit value.

[0075] Fig. 6 is a map of the upper limit current when the battery packs 17, 18 are in a charging state, used by the current-related upper limit setting circuit 30 in Fig. 4, 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. In the map in Fig. 6, upper limit current regions I11, I12, and I13 corresponding to the temperature and SOC of the battery packs 17, 18 are defined. The magnitudes of the current values ​​[A] in the upper limit current regions I11, I12, and I13 have a relationship of I11>I12>I13.

[0076] The map of Fig. 6 is stored in the memory 24b of the control unit 24. The current-related upper limit setting circuit 30 uses the map of Fig. 6 to set upper limit currents for the corresponding regions I11, I12, I13 for each of the battery packs 17, 18 based on the temperatures and SOC of the battery packs 17, 18, and sets the minimum value of the upper limit currents of the battery packs 17, 18 as the current-related upper limit value.

[0077] In the embodiment shown in FIG. 2, two battery packs 17, 18 are electrically connected to the power path 26, but when only one of the battery packs 17, 18 is electrically connected to the power path 26, the current-related upper limit setting circuit 30 sets the upper limit current of the connected battery pack 17, 18 as the current-related upper limit.

[0078] In this embodiment, when the SOC of the battery cells 17a, 18a is close to 100%, when the temperature of the battery packs 17, 18 reaches a temperature condition that prohibits charging, or when it is necessary to prevent unintended charging of the battery packs 17, 18, the battery management units 17f, 18f open the charging switching elements 17b, 18b to switch the battery packs 17, 18 to a charging prohibited state in order to prevent the battery cells 17a, 18a from being overcharged and degraded. When the electric motorcycle 1 runs with the charging switching elements 17b, 18b open, the battery management units 17f, 18f close the discharging switching elements 17d, 18d to switch the battery packs 17, 18 to a discharging enabled state. At this time, the current flows intensively through the discharging rectifier diodes 17c, 18c, and there is a risk that the current flowing through the discharging rectifier diodes 17c, 18c may exceed the allowable current.

[0079] As described above, when the battery packs 17, 18 are in a charging-prohibited state and in a discharging-enabled state, in order to electrically protect the discharging rectifier diodes 17c, 18c, the current-related upper limit setting circuit 30 sets the allowable current of the discharging rectifier diodes 17c, 18c as the upper limit current of the battery packs 17, 18. Furthermore, the current-related upper limit setting circuit 30 sets the minimum value of the upper limit currents of the battery packs 17, 18 for which the allowable currents of the discharging rectifier diodes 17c, 18c have been set, as the current-related upper limit.

[0080] [Upper torque calculation circuit] The torque upper limit calculation circuit 31 calculates a torque upper limit of a command torque to be issued to the motor 14 via the motor driver 21 so as to maintain a state in which the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current, based on the accelerator operation amount transmitted from the accelerator grip sensor 12 and the current-related upper limit set by the current-related upper limit setting circuit 30. More specifically, the torque upper limit calculation circuit 31 calculates the torque upper limit from the characteristic between the applied current and output torque of the motor 14, based on the upper limit current related to the current-related upper limit.

[0081] [Command torque calculation circuit] 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 amount of accelerator operation transmitted from the accelerator grip sensor 12 and the rotation speed of the motor 14 transmitted from the motor rotation speed sensor 16.

[0082] When the command torque exceeds the torque upper limit calculated by the torque upper limit calculation circuit 31, the command torque calculation circuit 32 corrects the command torque so that the command torque is equal to or less than the torque upper limit in order to maintain a state in which the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current.

[0083] Fig. 7 is a graph showing one embodiment of the command torque corrected by command torque calculation circuit 32 of Fig. 4, with the horizontal axis representing the accelerator operation amount and the vertical axis representing the command torque. The solid line in the graph of Fig. 7 represents the progress of the command torque after correction, the dashed line represents the torque upper limit value calculated by torque upper limit value calculation circuit 31, and the dashed line represents the progress of the command torque before correction based on the accelerator operation amount. As shown by the solid line in the graph of Fig. 7, when the command torque reaches the torque upper limit value, the command torque is corrected to the torque upper limit value which is a steady value.

[0084] FIG. 8 is a graph showing another example of the command torque corrected by the command torque calculation circuit 32 of FIG. 4, where the horizontal axis indicates the accelerator operation amount and the vertical axis indicates the command torque. The solid line in the graph of FIG. 8 indicates the change in the command torque after correction, the dashed line indicates the torque upper limit calculated by the torque upper limit calculation circuit 31, and the dashed line indicates the change in the pre-correction command torque based on the accelerator operation amount. As shown by the solid line in the graph of FIG. 8, the command torque is suppressed to be equal to or lower than the torque upper limit value until the accelerator operation amount becomes maximum, and the rate of increase according to the accelerator operation amount is suppressed so that the current flowing through the battery packs 17, 18 is equal to or lower than the upper limit current, and the command torque is corrected to increase more gradually than the pre-correction command torque. More specifically, the command torque is corrected according to the following relationship. Command torque = Pre-correction command torque × (current-related upper limit value / maximum current-related upper limit value) The maximum current-related upper limit value is the maximum value of the current-related upper limit value, and is a value corresponding to the upper limit current regions I1 and I11 in the maps shown in FIG. 5 and FIG.

[0085] [Battery charging determination circuit] When the electric motorcycle 1 performs regenerative braking, the battery charging determination circuit 33 determines whether or not to charge the battery packs 17, 18 according to 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 lower than the upper limit current, the battery management units 17f, 18f close the charging switching elements 17b, 18b, thereby switching the battery packs 17, 18 to a chargeable state and charging is 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 switching elements 17b, 18b, thereby switching the battery packs 17, 18 to a charging prohibited state and charging is stopped.

[0086] [Control method] The control method executed by the electrical circuit 25 shown in FIG. 2 includes a drive control for driving the motor 14 by putting the battery packs 17, 18 into a discharging state in which they release power toward the motor 14, and a regenerative control for charging the battery packs 17, 18 by putting the battery packs 17, 18 into a charging state in which they receive power from the motor 14.

[0087] Fig. 9 is a flowchart of the control of the motor 14 performed using the electric circuit 25 of Fig. 2, and particularly shows the control process executed by the processor 24a. A program for performing control according to the illustrated flowchart is stored in the memory 24b of the control unit 24.

[0088] 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 both battery packs 17, 18 are electrically connected to the power path 26, or whether only one of the battery packs 17, 18 is electrically connected to the power path 26.

[0089] Next, in step S2, the control unit 24 acquires the SOCs of the battery cells 17a, 18a and the temperatures of the battery packs 17, 18 transmitted from the battery management units 17f, 18f.

[0090] Next, in step S3, the current-related upper limit setting circuit 30 of the control unit 24 sets the upper limit current of the current flowing through the battery packs 17, 18 as the current-related upper limit value, as described above. More specifically, when drive control is being performed, that is, when the battery packs 17, 18 are in a discharging state, the current-related upper limit 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, using the map shown in FIG. 5. Alternatively, when regenerative control is being performed, that is, when the battery packs 17, 18 are in a charging state, the current-related upper limit 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, using the map shown in FIG. 6. When the two battery packs 17, 18 are electrically connected to the power path 26, the minimum value of the upper limit currents of the two battery packs 17, 18 is set as the current-related upper limit value. Moreover, 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 pack 17, 18 is set as the current-related upper limit value. Furthermore, when the switch box 22 closes one of the switching 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 pack 17, 18 is set as the current-related upper limit value.

[0091] Next, in step S4, when drive control is being performed by the control unit 24, it is determined whether or not the battery packs 17, 18 are in a charging prohibited state. More specifically, when drive control is being performed, i.e., when the battery packs 17, 18 are in a discharging state, if the battery packs 17, 18 are in a charging prohibited state (YES in step S4), the control process proceeds to step S5, whereas if the battery packs 17, 18 are not in a charging prohibited state (NO in step S4), the control process skips step S5 and proceeds to step S6.

[0092] In step S5, since the battery packs 17, 18 are in a dischargeable state and a charge-prohibited state, the current-related upper limit setting circuit 30 sets the allowable currents of the discharge rectifier diodes 17c, 18c as the upper limit currents of the battery packs 17, 18 for the purpose of electrically protecting the discharge rectifier diodes 17c, 18c, as described above. Furthermore, the current-related upper limit setting circuit 30 resets the minimum value of the upper limit currents of the battery packs 17, 18 for which the allowable currents of the discharge rectifier diodes 17c, 18c have been set, as the current-related upper limit. When only one of the battery packs 17, 18 is electrically connected to the power path 26, the current-related upper limit setting circuit 30 resets the allowable currents of the discharge rectifier diodes 17c, 18c of the connected battery packs 17, 18 as the current-related upper limit.

[0093] Next, in step S6, the control unit 24 determines whether regeneration control is being performed, i.e., whether the battery packs 17, 18 are in a charging state where power is being supplied from the motor 14. More specifically, if the battery packs 17, 18 are in a charging state (YES in step S6), the control process proceeds to step S7, whereas if the battery packs 17, 18 are not in a charging state (NO in step S6), i.e., if drive control is being performed, the control process skips steps S7 and S8 and proceeds to step S9.

[0094] In step S7, the battery charging determination circuit 33 of the control unit 24 determines whether the current-related value, i.e., the current, of the battery packs 17, 18 is greater than a current-related upper limit value, i.e., the upper limit current. More specifically, if the current flowing through the battery packs 17, 18 is greater than the upper limit current (YES in step S7), the control process proceeds to step S8, whereas if the current flowing through the battery packs 17, 18 is equal to or less than the upper limit current (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 are charged by regenerative control.

[0095] In step S8, since the current flowing through the battery packs 17, 18 is greater than the upper limit current, the battery charging determination circuit 33 transmits an electrical signal including an instruction to open the charging switching elements 17b, 18b to the battery management units 17f, 18f as described above. By opening the charging switching elements 17b, 18b, the battery management units 17f, 18f switch the battery packs 17, 18 to a charging prohibited state, release the charging state of the battery packs 17, 18, and stop charging the battery packs 17, 18.

[0096] Next, in step S9, the torque upper value calculation circuit 31 of the control unit 24 calculates the torque upper value from the characteristics between the applied current and the output torque of the motor 14 based on the current-related upper limit value, i.e., the upper limit current of the battery packs 17, 18, as described above.

[0097] 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.

[0098] 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.

[0099] Next, in step S12, the command torque calculation circuit 32 determines whether or not the command torque needs to be corrected. More specifically, if the command torque exceeds the torque upper limit value (YES in step S12), it is determined that the command torque needs to be corrected, and the control process proceeds to step S13, whereas if the command torque is equal to or less than the torque upper limit value (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.

[0100] In step S13, the command torque calculation circuit 32 corrects the command torque so that the command torque is equal to or less than the torque upper limit value in order 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 command torque after correction is calculated by the method of correcting the command torque shown in FIG.

[0101] Next, in step S14, the control unit 24 transmits a command torque to be output by the motor 14 as an electrical signal to the motor driver 21. By receiving 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 regeneratively brake the motor 14 so that the motor 14 outputs the command torque.

[0102] Following the flow including steps S1 to S14, the motor 14 is controlled, including the drive control and regeneration control.

[0103] [Effects] The electric motorcycle 1 configured in this manner has the following features.

[0104] The method for controlling the motor 14 of the electric motorcycle 1 according to the present embodiment is as follows: setting a current-related upper limit value of a current-related value related to a current flowing through a battery pack (17, 18) of the electric motorcycle (1) in accordance with a vehicle state when the electric motorcycle (1) is driven by the motor (14); The torque upper limit value of a command torque to be commanded to the motor 14 is calculated based on the accelerator operation amount input to the electric motorcycle 1 and the current-related upper limit value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value.

[0105] According to this embodiment, the method for controlling the motor 14 of the electric motorcycle 1 calculates a torque upper limit value of a command torque to the motor 14 so that a current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than a current-related upper limit value. By calculating the torque upper limit value of the command torque, it is possible to electrically protect battery-related components even if the battery packs 17, 18 mounted have a small allowable current or do not have a current limiting function. Therefore, the electric motorcycle 1 is provided with a function for protecting battery-related components, and various batteries and battery control circuits can be freely selected and mounted thereon. Furthermore, by calculating the upper torque limit of the command torque, it is easier to suppress the influence on the driving feeling compared to the case where the current of the battery packs 17, 18 themselves is controlled.

[0106] Furthermore, the command torque is calculated so as to increase with an increase in the accelerator operation amount, when the accelerator operation amount is at a maximum, so that the current-related value becomes the current-related upper limit value.

[0107] According to this embodiment, the command torque can be changed according to the accelerator operation amount. Also, 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 becomes maximum, the command torque can be increased according to an increase in the accelerator operation amount, thereby making it possible to approach the operation feeling of the driver.

[0108] Moreover, the command torque is calculated according to the following relationship: Command torque = Pre-correction command torque × (current-related upper limit value / maximum current-related upper limit value) The pre-correction command torque is a torque based on the accelerator operation amount input by the driver. The maximum current-related upper limit value is the maximum value of the current-related upper limit values.

[0109] According to this embodiment, the command torque is suppressed to be equal to or less than the torque upper limit value until the accelerator depression amount becomes maximum, and the current-related value is equal to or less than the current-related upper limit value, thereby electrically protecting the battery-related components.

[0110] The command torque is calculated based on the accelerator operation amount and the rotation speed of the motor 14.

[0111] According to this embodiment, the command torque can be made different between when starting and when traveling at a constant speed because the command torque is calculated based on the accelerator operation amount and the rotation speed of the motor 14. For example, by setting the command torque taking into consideration the rotation speed of the motor 14, it is possible to prevent the current-related value from exceeding the current-related upper limit value even when the rotation speed is low, such as when starting, and to provide an appropriate starting torque to the electric motorcycle 1.

[0112] In addition, the current-related upper limit value is set based on the upper limit current permitted to flow through the battery packs 17 and 18.

[0113] According to this embodiment, the current-related upper limit value is set based on the upper limit current allowed to flow through the battery packs 17, 18, and the current flowing through the battery packs 17, 18 is controlled to be equal to or less than the upper limit current, making it easier to electrically protect the battery packs 17, 18. In addition, the current flowing through the battery packs 17, 18 can be controlled to be equal to or lower than the upper limit current by using the power or temperature related to the current as a current-related value.

[0114] In addition, an upper limit current is set for each of the battery packs 17 and 18. The current-related upper limit value is set based on the smallest upper limit current among the upper limit currents set for the battery packs 17 and 18.

[0115] According to the present embodiment, the current-related upper limit value is set based on the smallest upper limit current among the upper limit currents set for each of the battery packs 17, 18, and the current flowing through the battery packs 17, 18 is controlled to be equal to or less than the smallest upper limit current, making it easy to electrically protect all of the battery packs 17, 18.

[0116] The control method is as follows: A drive control for driving the motor 14 by putting the battery packs 17 and 18 into a discharging state in which the battery packs 17 and 18 discharge power toward the motor 14; and regenerative control for charging the battery packs 17, 18 by putting the battery packs 17, 18 into a charging state in which power is supplied from the motor 14 when the electric motorcycle 1 performs regenerative braking. The upper limit current varies depending on whether the battery packs 17, 18 are in a discharging or charging state.

[0117] According to this embodiment, the upper limit current varies depending on whether the battery packs 17, 18 are in a discharging state or a charging state, and an appropriate value is set. Therefore, even if the battery packs 17, 18 are in a discharging state or a charging state, it is easy to electrically protect the battery packs 17, 18.

[0118] In addition, regenerative control is When the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 is equal to or lower than an upper limit current, the battery packs 17, 18 are in a charging state and the battery packs 17, 18 are charged; When the electric motorcycle 1 performs regenerative braking, if the current flowing through the battery packs 17, 18 exceeds an upper limit current, the charging state of the battery packs 17, 18 is released.

[0119] According to this embodiment, 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 released from their charged state. This makes it difficult for the battery packs 17, 18 to be overcharged, and makes it easier to electrically protect the battery packs 17, 18.

[0120] The current-related upper limit value is set based on the upper limit current of the circuit elements included in the electric circuit 25 electrically connected to the battery packs 17 and 18 and the motor 14 .

[0121] According to this embodiment, the current-related upper limit value is set based on the upper limit current for electrically protecting the circuit element, and the current flowing through the circuit element is controlled to be equal to or less than the upper limit current, making it easier to electrically protect the circuit element.

[0122] In addition, the electric circuit 25 includes: charging switching elements 17b, 18b and discharging switching elements 17d, 18d electrically connected to the battery cells 17a, 18a; a discharge-time rectifier diode 17c, 18c and a charge-time rectifier diode 17e, 18e electrically connected in parallel to the charge-time switching elements 17b, 18b, The current-related upper limit is set to the allowable current of the rectifier diodes 17c, 18c during discharge when the charging switching elements 17b, 18b are open.

[0123] According to this embodiment, when the battery packs 17, 18 are in a discharging state in which they release power toward the motor 14 and the charging switching elements 17b, 18b are open, the current-related upper limit value is set to the allowable current of the discharge-time rectifier diodes 17c, 18c, making it easy to electrically protect the discharge-time rectifier diodes 17c, 18c.

[0124] In addition, when the battery packs 17, 18 are in a chargeable state in which the charging switching elements 17b, 18b are closed to allow current to flow from the motor 14 to the battery packs 17, 18, when the conditions for preventing overcharging of the battery cells 17a, 18a are satisfied, the charging switching elements 17b, 18b are opened to switch to a charge-prohibited state in which current is prohibited from flowing from the motor 14 to the battery packs 17, 18.

[0125] According to this embodiment, when the battery packs 17, 18 are in a chargeable state, if the conditions for preventing overcharging of the battery cells 17a, 18a are satisfied, the battery packs 17, 18 are switched to a charging prohibited state, thereby preventing overcharging of the battery cells 17a, 18a.

[0126] In addition, the control unit 24 of the motor 14 of the electric motorcycle 1 of this embodiment is a current-related upper limit setting circuit 30 that sets a current-related upper limit value related to a current flowing through the battery packs 17, 18 of the electric motorcycle 1 in accordance with a vehicle state when the electric motorcycle 1 is driven by the motor 14; The electric motorcycle 1 is provided with a torque upper limit calculation circuit 31 that calculates a torque upper limit value of a command torque to be commanded to the motor 14 based on the accelerator operation amount and the current-related upper limit value input to the electric motorcycle 1 so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value.

[0127] According to this embodiment, the control unit 24 of the motor 14 of the electric motorcycle 1 calculates a torque upper limit value of a command torque to the motor 14 so that a current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than a current-related upper limit value. By calculating the torque upper limit value of the command torque, it is possible to electrically protect battery-related components even if the battery packs 17, 18 mounted have a small allowable current or do not have a current limiting function. Therefore, the electric motorcycle 1 is provided with a function to protect battery-related components, and various batteries and battery control circuits can be freely selected and mounted thereon. Furthermore, by calculating the upper torque limit of the command torque, it is easier to suppress the influence on the driving feeling compared to the case where the current of the battery packs 17, 18 themselves is controlled.

[0128] The electric motorcycle 1 of this embodiment also includes a control unit 24.

[0129] According to this embodiment, the torque upper limit value of the command torque to the motor 14 is calculated so that a current-related value related to the current flowing through the battery packs 17, 18 is equal to or less than a current-related upper limit value when the electric motorcycle 1 is driven. By calculating the torque upper limit value of the command torque, it is possible to electrically protect the battery-related components even if the battery packs 17, 18 mounted have a small allowable current or do not have a current limiting function. Therefore, the electric motorcycle 1 is provided with a function to protect the battery-related components, and various batteries and battery control circuits can be freely selected and mounted thereon. Furthermore, by calculating the torque upper limit of the command torque, the influence on the driving feeling can be easily suppressed compared to the case where the battery packs 17, 18 themselves are subjected to current control. For example, when the command torque is equal to or less than the torque upper limit, the command torque is not suppressed and is issued to the motor 14, making it easier to suppress the influence on the driving feeling. When the command torque is greater than the torque upper limit, the command torque is corrected to be suppressed and issued to the motor 14, making it possible to electrically protect battery-related components. In particular, the method of correcting the command torque shown in FIG. 8 makes it difficult for the command torque to suddenly change near the torque upper limit, making it easier to suppress the influence on the driving feeling.

[0130] [Other embodiments] The present disclosure is not limited to the configurations of the above-described embodiments, and various modifications are possible.

[0131] In the above-described embodiment, the electric vehicle 1 is a two-wheeled electric vehicle, but it may be a three-wheeled or four-wheeled vehicle. It is preferably used for a saddle-type vehicle, which is lighter than a four-wheeled vehicle in which the left and right wheels are spaced apart in the vehicle width direction, and has a large effect on the driving feeling. A saddle-type vehicle refers to a type of vehicle in which the driver sits on a seat with a saddle so that both feet of the driver are positioned on the left and right sides of the vehicle when in a riding position.

[0132] In the above embodiment, the two battery packs 17 and 18 are connected in parallel, but they may be connected in series. Also, a single battery pack may be electrically connected to the power path.

[0133] In the above-described embodiment, the two battery packs 17 and 18 are detachable from the main body 2. However, they may be mounted on the main body 2 so as not to be detachable.

[0134] In the above-described embodiment, the upper limit current of the battery packs 17, 18 is set as the 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 power or temperature that increases as the current increases, may also be set as the current-related upper limit value.

[0135] In the above-described embodiment, when the battery packs 17, 18 are in a charging-prohibited state but in a discharging-enabled state, the current-related upper limit setting circuit 30 sets the allowable current of the discharging rectifier diodes 17c, 18c as the upper limit current of the battery packs 17, 18 in order to electrically protect the discharging rectifier diodes 17c, 18c. However, when the battery packs 17, 18 are in a discharging-prohibited state but in a charging-enabled state, the allowable current of the charging rectifier diodes 17e, 18e may be set as the upper limit current of the battery packs 17, 18 in order to electrically protect the charging rectifier diodes 17e, 18e from excessive discharging of the battery packs 17, 18.

[0136] The present disclosure is not limited to electric vehicles, but can also be applied to hybrid vehicles equipped with a mode in which the vehicle runs on a motor. The vehicle structure, i.e., the layout of components such as the battery pack and the motor, may be other than the arrangement disclosed in the above embodiment. For example, the motor may be an in-wheel motor, and the battery pack may be mounted on a part other than the main body.

[0137] In the above-described embodiment, the electric motorcycle includes the electric circuit 25, but may include an electric circuit of another configuration. For example, the control unit may have some or all of the functions of the battery management unit. Also, as an alternative to a switch box, the control unit may have the functions of a switch box and control the electrical connection between the battery pack and the inverter circuit via the power path by switching the opening and closing of a switching element. Furthermore, the switch box may have some of the functions of the control unit.

[0138] The first aspect of the present disclosure is setting a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle in accordance with a vehicle state when the electric vehicle is driven by a motor; The present invention provides a method for controlling a motor of an electric vehicle, comprising: calculating a torque upper limit value of a command torque to be commanded to the motor based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value.

[0139] A second aspect of the present disclosure is The present invention provides a control method according to a first aspect, wherein the command torque is calculated to increase in accordance with an increase in the accelerator operation amount so that, when the accelerator operation amount is maximum, the current-related value becomes the current-related upper limit value.

[0140] A third aspect of the present disclosure is The control method according to the second aspect provides a control method, wherein the command torque is calculated according to the following relationship: Command torque = Pre-correction command torque × (current-related upper limit value / maximum current-related upper limit value) The pre-correction command torque is a torque based on the accelerator operation amount input by the driver. The maximum current-related upper limit value is the maximum value of the current-related upper limit values.

[0141] A fourth aspect of the present disclosure is In the control method according to the first or second aspect, the command torque is calculated based on the accelerator operation amount and a rotation speed of the motor.

[0142] A fifth aspect of the present disclosure is The control method according to any one of the first to fourth aspects, wherein the current-related upper limit value is set based on an upper limit current allowed to flow through the battery.

[0143] A sixth aspect of the present disclosure is When the battery includes a plurality of batteries electrically connected in parallel, The current-related upper limit value is set for each of the plurality of batteries, The present invention provides a control method according to any one of the first to fifth aspects, wherein the current-related upper limit value is set based on the smallest current-related upper limit value among the current-related upper limit values ​​set for each of the plurality of batteries.

[0144] A seventh aspect of the present disclosure is The control method includes: a drive control for driving the motor by putting the battery into a discharging state in which the battery discharges electric power toward the motor; and regenerative control for charging the battery by bringing the battery into a charging state in which electric power is supplied from the motor when the electric vehicle performs regenerative braking. The control method according to any one of the first to sixth aspects, wherein the current-related upper limit varies depending on whether the battery is in the discharging state or the charging state.

[0145] An eighth aspect of the present disclosure is The regenerative control includes: When the electric vehicle performs regenerative braking, if the current-related value is equal to or less than the current-related upper limit value, the battery is in the charging state and the battery is charged; The present invention provides a control method according to a seventh aspect, comprising: releasing the state of charge of the battery if the current-related value exceeds the current-related upper limit value when the electric vehicle performs regenerative braking.

[0146] A ninth aspect of the present disclosure is a method for producing a semiconductor device comprising: A control method according to any one of the first to eighth aspects is provided, wherein the current-related upper limit value is set based on an upper limit current of a circuit element included in an electric circuit electrically connected to the battery and the motor.

[0147] A tenth aspect of the present disclosure is a method for manufacturing a semiconductor device comprising: The electrical circuit includes: a switching element electrically connected to the battery; a diode electrically connected in parallel to the switching element, A ninth aspect provides a control method according to the present invention, wherein the current-related upper limit is set to an allowable current of the diode when the switching element opens.

[0148] An eleventh aspect of the present disclosure is a method for manufacturing a semiconductor device comprising: A control method according to a tenth aspect is provided, in which, when the battery is in a chargeable state in which the switching element is closed to allow current to flow from the motor to the battery, when a condition for preventing overcharging of the battery is satisfied, the switching element is opened to switch to a charge-prohibited state in which current is prohibited from flowing from the motor to the battery.

[0149] A twelfth aspect of the present disclosure is a method for manufacturing a semiconductor device comprising: a current-related upper limit setting unit that sets a current-related upper limit value related to a current flowing through a battery of an electric vehicle in accordance with a vehicle state when the electric vehicle is driven by a motor; Provided is a control device for a motor of an electric vehicle, comprising: a torque upper value calculation unit that calculates a torque upper value of a command torque to be commanded to the motor based on an accelerator operation amount input to the electric vehicle and the current-related upper value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper value.

[0150] A thirteenth aspect of the present disclosure is a method for producing a semiconductor device comprising the steps of: An electric vehicle is provided, comprising the control device according to a twelfth aspect. [Explanation of symbols]

[0151] 1. Electric vehicles (electric two-wheelers) 14 Motor 17,18 Battery pack 17a,18a Battery cells 17b, 18b Charging switching element 17c,18c Discharge rectifier diode 17d, 18d Discharge switching element 17e,18e Charging rectifier diode 24 Control Unit 25 Electrical Circuits 30 Current-related upper limit setting unit (current-related upper limit setting circuit) 31 Torque upper limit calculation unit (torque upper limit calculation circuit)

Claims

1. setting a current-related upper limit value of a current-related value related to a current flowing through a battery of the electric vehicle in accordance with a vehicle state when the electric vehicle is driven by a motor; a torque upper limit value of a command torque to be commanded to the motor, based on an accelerator operation amount input to the electric vehicle and the current-related upper limit value, so as to maintain a state in which the current-related value is equal to or less than the current-related upper limit value.

2. 2 . The control method according to claim 1 , wherein the command torque is calculated to increase with an increase in the accelerator operation amount so that, when the accelerator operation amount is maximum, the current-related value becomes the current-related upper limit value.

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

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

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

6. When the battery includes a plurality of batteries electrically connected in parallel, The current-related upper limit value is set for each of the plurality of batteries, 3. The control method according to claim 1, wherein the current-related upper limit value is set based on a smallest current-related upper limit value among the current-related upper limit values ​​set for the plurality of batteries.

7. The control method includes: a drive control for driving the motor by putting the battery into a discharging state in which the battery discharges electric power toward the motor; and regenerative control for charging the battery by bringing the battery into a charging state in which electric power is supplied from the motor when the electric vehicle performs regenerative braking.

3. The method of claim 1 or 2, wherein the current-related upper limit varies depending on whether the battery is in the discharging state or the charging state.

8. The regenerative control includes: When the electric vehicle performs regenerative braking, if the current-related value is equal to or less than the current-related upper limit value, the battery is in the charging state and the battery is charged; The method of claim 7, further comprising releasing the state of charge of the battery if the current-related value exceeds the current-related upper limit value when the electric vehicle is performing regenerative braking.

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 an electric circuit electrically connected to the battery and the motor.

10. The electrical circuit includes: a switching element electrically connected to the battery; a diode electrically connected in parallel to the switching element, 10. The method of claim 9, wherein the current-related upper limit is set to an allowable current of the diode when the switching element opens.

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

12. a current-related upper limit setting unit that sets a current-related upper limit value related to a current flowing through a battery of an electric vehicle in accordance with a vehicle state when the electric vehicle is driven by a motor; a torque upper value calculation unit that calculates a torque upper value of a command torque to be commanded to the motor, based on an accelerator operation amount input to the electric vehicle and the current-related upper value, so as to maintain a state where the current-related value is equal to or less than the current-related upper value.

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

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