Electric vehicles

Abstract

To provide an electric vehicle which can suppress shortage of energy of a second power storage device in vehicle travel while reducing the size of the second storage device, and can improve a life of a first power storage device.SOLUTION: An electric vehicle includes: a first power storage device 4; a second power storage device 5; a power converter 10; a first switch S3 for forming a circuit for connecting the power converter 10 and an inverter 2 without via the second power storage device 5; a second switch S4 for forming a circuit for connecting the power converter 10 and the inverter 2 via the second power storage device 5; and a third switch S5 for forming a circuit for connecting the second power storage device 5 and a ground, wherein in stopping of a motor 1 and / or power running of the motor 1, the first switch S3 is brought in a connection state, the second switch S4 is brought in a cut-off state and the third switch S5 is brought in the connection state, energy is supplied to the second power storage device 5 from the first power storage device 4 while stepping down an output voltage of the first power storage device 4.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric vehicle equipped with a motor capable of power running and regenerating, and an electricity storage device capable of supplying energy to the motor. [Background technology]

[0002] An example of an electric vehicle that is equipped with a motor capable of power running and regenerating electricity and a power storage device capable of supplying energy to the motor, obtains thrust from the driving force of the motor, and is capable of recovering energy in the power storage device by adjusting the braking torque of the drive wheels, is described in Patent Document 1. With such an electric vehicle, the motor can be driven by supplying energy to an inverter at any timing from both a battery with high-capacity characteristics and a capacitor with high-output characteristics. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-166367 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-described conventional technology, although the battery (first power storage device) and the capacitor (second power storage device) share the energy supply to drive the motor, if the capacitor runs out of energy because regeneration is not fast enough, it is necessary to supply energy from the battery alone. However, for example, when the vehicle accelerates, a sudden energy supply is required. If energy is supplied from the battery alone, the sudden energy supply may cause the battery to heat up and shorten its lifespan. In addition, to avoid a shortage of energy in the capacitor while the vehicle is running, it is possible to use a charger to charge the capacitor with more energy in advance, such as when the vehicle is not in use. However, in this case, the capacitor would become larger.

[0005] The present invention has been made in consideration of these circumstances, and aims to provide an electric vehicle that can reduce the size of the second storage device while preventing the second storage device from running out of energy when the vehicle is running, and can improve the life of the first storage device. [Means for solving the problem]

[0006] The invention of claim 1 is an electric vehicle having a motor capable of power running and an inverter capable of converting direct current to alternating current, the electric vehicle comprising: a first power storage device having high-capacity characteristics; a second power storage device having high-output characteristics; a power converter having a function of stepping down during power running; a circuit in which the power converter having a function of stepping down during power running is connected to the first power storage device and the second power storage device is connected in series between a reactor of the power converter and the inverter; a first switch forming a circuit connecting the power converter and the inverter without passing through the second power storage device; a second switch forming a circuit connecting the power converter and the inverter via the second power storage device; and a third switch forming a circuit connecting the second power storage device and ground. ,before When the motor is powered, the first switch is in a connected state, the second switch is in a disconnected state, and the third switch is in a connected state, and the output voltage of the first power storage device is reduced while the first power storage device is supplied with power. via the power converter the second power storage device and the inverter It is characterized by supplying energy to

[0007] The invention of claim 2 is characterized in that, in the electric vehicle of claim 1, the storage state of the second storage device can be determined based on the voltage of the second storage device, and when the storage state of the second storage device is below a predetermined value, energy is supplied to the second storage device while reducing the output voltage of the first storage device.

[0008] The invention of claim 3 is characterized in that, in the electric vehicle of claim 1 or claim 2, the motor is capable of power running and regeneration, the power converter has a function of reducing voltage during power running and a function of increasing voltage during regeneration, and during regeneration of the motor, the first switch is in a cut-off state, the second switch is in a connected state, and the third switch is in a cut-off state, and energy is recovered by the first storage device and the second storage device while the output voltage of the second storage device is increased.

[0009] The invention of claim 4 is characterized in that, in the electric vehicle of any one of claims 1 to 3, when the motor is powered, the first switch is in a cut-off state, the second switch is in a connected state, and the third switch is in a cut-off state, and energy is supplied to the inverter from the first storage device and the second storage device while reducing the output voltage of the first storage device.

[0010] The invention described in claim 5 is characterized in that, in the electric vehicle described in any one of claims 1 to 4, when the motor is powered, the first switch is in a cut-off state, the second switch is in a cut-off state, and the third switch is in a connect state, and energy is supplied from the second storage device to the inverter.

[0011] The invention of claim 6 is characterized in that, in the electric vehicle of claim 5, the temperature state of the first storage device can be determined based on the temperature of the first storage device, and when the temperature of the first storage device is equal to or higher than a predetermined value while the motor is powered, energy is supplied from the second storage device to the inverter.

[0012] The invention of claim 7 is characterized in that in the electric vehicle of any one of claims 1 to 6, the first power storage device has higher voltage characteristics than the second power storage device.

[0013] The invention of claim 8 is characterized in that in the electric vehicle of any one of claims 1 to 7, the amount of energy when the first power storage device is fully charged is greater than the amount of energy when the second power storage device is fully charged.

[0014] The invention of claim 9 is characterized in that in the electric vehicle of any one of claims 1 to 8, the first power storage device is a replaceable cassette-type power storage device.

[0015] The invention described in claim 10 is characterized in that, in the electric vehicle described in any one of claims 1 to 9, the first power storage device is a high-capacity lithium-ion battery or a high-capacity nickel-metal hydride battery, and the second power storage device is any one of a high-output lithium-ion battery, a high-output nickel-metal hydride battery, a lithium-ion capacitor, or an electric double layer capacitor. [Effects of the Invention]

[0016] According to the present invention , Mo When the motor is powered, the first switch is in a connected state, the second switch is in a disconnected state, and the third switch is in a connected state, and the output voltage of the first power storage device is reduced while the first power storage device is supplied with power. Through a power converter Second power storage device and inverter Since energy is supplied to the first power storage device, it is possible to reduce the size of the second power storage device while preventing the second power storage device from running short of energy, and to extend the life of the first power storage device. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing an electric vehicle according to an embodiment of the present invention; [Figure 2] A circuit diagram showing a power conversion device of the electric vehicle [Figure 3] Conceptual diagram showing the power conversion device for the electric vehicle [Figure 4] Schematic diagram showing the control relationship of the electric vehicle [Figure 5] Time chart showing power control of the electric vehicle [Figure 6] 1 is a flowchart showing the overall power control of the electric vehicle. [Figure 7] Graph showing the required characteristics of the electric vehicle (vehicle requirements for drive wheels) [Figure 8]Graph showing the required characteristics of the electric vehicle (motor requirements for the drive wheels) [Figure 9] Graph showing the required characteristics of the electric vehicle (vehicle requirements for the driven wheels) [Figure 10] Graph showing the required characteristics of the electric vehicle (braking requirements for the driven wheels) [Figure 11] A flowchart showing the request processing control of the electric power control of the electric vehicle. [Figure 12] Graph showing the driver's request table (Table 1) of the electric vehicle [Figure 13] Graph showing the driver's request table (Table 2) of the electric vehicle [Figure 14] Graph showing the driver's request table (Table 3) of the electric vehicle [Figure 15] Graph showing the driver's request table (Table 4) of the electric vehicle [Figure 16] Graph showing the driver's request table (Table 5) of the electric vehicle [Figure 17] Graph showing the driver's request table (Table 6) of the electric vehicle [Figure 18a] 1 is a flowchart showing motor control for power control of the electric vehicle. [Figure 18b] 1 is a flowchart showing motor control for power control of the electric vehicle. [Figure 19] Table showing the power conversion circuit control of the electric vehicle [Figure 20] Graph showing the voltage requirement table (Table A) for the same electric vehicle [Figure 21] Graph showing the voltage requirement table (Table B) for the same electric vehicle [Figure 22] Graph showing the voltage requirement table (Table C) of the same electric vehicle [Figure 23] Graph showing the voltage requirement table (Table D) for the same electric vehicle [Figure 24] Graph showing the voltage requirement table (Table E) of the electric vehicle [Figure 25] Graph showing the state of charge of the first power storage device of the electric vehicle [Figure 26]Graph showing the state of charge of the second power storage device of the electric vehicle [Figure 27] Table showing combinations of storage devices for the electric vehicle DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The electric vehicle according to this embodiment is a saddle-type vehicle such as a motorcycle that can be driven by the driving force of a motor, and as shown in FIGS. 1 to 4, is mainly equipped with a motor 1, an inverter 2, mechanical brakes (3a, 3b), a first power storage device 4, a second power storage device 5, an accelerator operation means 6, a mechanical brake operation means 7, a regenerative brake operation means 8, a power converter 10, an ECU 11, a start switch 12, and a monitor 13 (auxiliary device).

[0019] The motor 1 is an electromagnetic motor that obtains driving force from energy supply, and as shown in Figures 2 and 3, is electrically connectable to the second power storage device 5, power converter 10, and first power storage device 4 via the inverter 2, and is capable of power running and regeneration. The inverter 2 (DC-AC inverter) is capable of converting direct current to alternating current, and in this embodiment, it is capable of converting the direct current of the first power storage device 4 and the second power storage device 5 into alternating current and supplying it to the motor 1.

[0020] The mechanical brakes are comprised of braking devices such as disc brakes or drum brakes that can apply braking by releasing energy, and are configured with a driving wheel mechanical brake 3a that applies braking by releasing the kinetic energy of the driving wheels Ta, and a driven wheel mechanical brake 3b that applies braking by releasing the kinetic energy of the driven wheels Tb. The driving wheel mechanical brakes 3a and driven wheel mechanical brakes 3b are connected to a mechanical brake operating means 7 via a brake actuator 9.

[0021] The mechanical brake operating means 7 is composed of a part (in this embodiment, an operating lever attached to the right end of the handlebar) that can control the mechanical brake (driven wheel mechanical brake 3b) to adjust the braking torque, and is configured so that the mechanical brake control unit 18 (see Figure 4) operates the brake actuator 9 in accordance with the amount of operation, thereby operating the driven wheel mechanical brake 3b.

[0022] The accelerator operation means 6 is made up of a part (in this embodiment, an accelerator grip attached to the right end of the handlebar) that can control the motor 1 to adjust the drive torque of the drive wheel Ta, and as shown in Figure 4, the inverter control unit 16 estimates the torque requirement according to the amount of operation and operates the motor 1 to obtain the desired drive force. The inverter control unit 16 is one of the control units formed in the ECU 11.

[0023] The power storage device is capable of supplying energy to the motor 1, and in this embodiment, is configured to include a first power storage device 4 and a second power storage device 5. The first power storage device 4 is made up of a storage battery having high-capacity characteristics, and as shown in FIG. 27, for example, a high-capacity lithium-ion battery or a high-capacity nickel-metal hydride battery can be used. The second power storage device 5 is made up of a storage battery having high-output characteristics, and as shown in FIG. 27, for example, any one of a high-output lithium-ion battery, a high-output nickel-metal hydride battery, a lithium-ion capacitor, or an electric double layer capacitor can be used.

[0024] More specifically, the first power storage device 4 has higher voltage characteristics than the second power storage device 5, and the amount of energy when fully charged of the first power storage device 4 is greater than the amount of energy when fully charged of the second power storage device 5. Furthermore, the first power storage device 4 according to this embodiment is a cassette-type power storage device that can be removed from the vehicle and replaced, and can be replaced with a first power storage device 4 in a fully charged state depending on the power storage state of the first power storage device 4.

[0025] The regenerative brake operation means 8 is made up of a component (in this embodiment, an operating lever attached to the left end of the handlebar) that controls the motor 1 to adjust the braking torque of the drive wheels Ta and recover energy in the power storage devices (first power storage device 4 and second power storage device 5), and is configured to perform regeneration of the motor 1 according to the amount of operation to obtain a desired braking force. By this regeneration of the motor 1, energy can be recovered in the first power storage device 4 and second power storage device 5.

[0026] The power converter 10 has a function of stepping down the voltage when the motor 1 is powered (when energy is supplied to the motor 1) and a function of stepping up the voltage when the motor 1 is regenerating (when energy is recovered from the motor 1), and is connected between the first power storage device 4 and the second power storage device 5 in the electric circuit as shown in Figures 2 and 3. More specifically, as shown in Figure 2, the power converter 10 is configured to have two semiconductor switch elements (MOSFETs) 10a and 10b, each having switches S1 and S2 and a diode as a rectifier, and a reactor 10c (coil).

[0027] Furthermore, according to the power converter 10 of this embodiment, by performing high-speed switching (duty control) on the switches S1 and S2 of the semiconductor switch elements 10a and 10b, when the motor 1 is powered (when current flows to the right in FIG. 3), the reactor 10c is located downstream of the semiconductor switch elements 10a and 10b, making it possible to step down the voltage, and when the motor 1 is regenerating (when current flows to the left in FIG. 3), the reactor 10c is located upstream of the semiconductor switch elements 10a and 10b, making it possible to step up the voltage.

[0028] More specifically, in this embodiment, as shown in Figures 2 and 3, a power converter 10 having a function of reducing voltage during power running is connected to the first storage device 4, and a circuit is provided in which a second storage device 5 is connected in series between a reactor 10c of the power converter 10 and the inverter 2, and when the motor 1 is powered, the output voltage (Vdc1) of the first storage device 4 is reduced by the power converter 10 and energy is supplied to the inverter 2 from the first storage device 4 and the second storage device 5, and when the motor 1 is regenerating, the output voltage (Vinv-Vdc2) of the second storage device 5 is increased by the power converter 10 and energy is recovered by the first storage device 4 and the second storage device 5.

[0029] 2, the present embodiment includes a first switch S3 that forms a circuit connecting the power converter 10 and the inverter 2 without the second power storage device 5, a second switch S4 that forms a circuit connecting the power converter 10 and the inverter 2 via the second power storage device 5, and a third switch S5 that forms a circuit connecting the second power storage device 5 and the ground (ground connection). Note that capacitors Ca and Cb for stabilization are connected to the circuit according to the present embodiment.

[0030] Furthermore, the first switch S3 and the second switch S4 according to this embodiment are configured by semiconductor switch elements (MOSFETs) 14 and 15 (which have diodes as rectifiers, similar to the semiconductor switch elements 10a and 10b), and the third switch S5 is configured by a switch that can turn on and off (connect or disconnect) the conduction of current. The first switch S3, the second switch S4, and the third switch S5 can be turned on and off (connected or disconnected) at any timing under the control of the circuit control unit 17.

[0031] 4, the ECU 11 has an inverter control unit 16, a circuit control unit 17, and a mechanical brake control unit 18, and is connected to the inverter 2, the power converter 10, the first power storage device 4, the second power storage device 5, and the brake actuator 9. The ECU 11 also has a voltage detection sensor 4a capable of detecting the voltage of the first power storage device 4, a temperature detection sensor 4b capable of detecting the temperature of the first power storage device 4, and a voltage detection sensor 5a capable of detecting the voltage of the second power storage device 5.

[0032] The voltage detection sensor 4a, the temperature detection sensor 4b, and the voltage detection sensor 5a are electrically connected to the circuit control unit 17, and the charge states of the first and second power storage devices 4 and 5 can be determined based on the voltages detected by the voltage detection sensor 4a and the voltage detection sensor 5a, respectively, and the temperature detection sensor 4b can detect the temperature of the first power storage device 4. The charge states of the first power storage device 4 and the second power storage device 5 are shown in FIG. 25 and FIG. 26, respectively.

[0033] When the motor 1 is powered, if the state of charge of the second storage device 5 is below the charging judgment value (below the charging judgment value in Figure 26), the first switch S3 is connected (ON state), the second switch S4 is disconnected (OFF state), and the third switch S5 is connected (ON state), and energy is supplied from the first storage device 4 to the inverter 2 and the second storage device 5 while the output voltage (Vdc1) of the first storage device 4 is lowered.

[0034] That is, when the motor 1 is powered, the first switch S3 is connected (ON state), the second switch S4 is disconnected (OFF state), and the third switch S5 is connected (ON state), thereby supplying energy from the first storage device 4 to the inverter 2 and also supplying energy to the second storage device 5 for charging. Similarly, when the motor 1 is stopped, the first switch S3 is connected (ON state), the second switch S4 is disconnected (OFF state), and the third switch S5 is connected (ON state), thereby supplying energy from the first storage device 4 to the second storage device 5 while reducing the output voltage (Vdc1) of the first storage device 4.

[0035] In this way, the electric vehicle according to this embodiment is capable of charging the second power storage device 5 by supplying energy from the first power storage device 4 to the second power storage device 5 while the first switch S3 is in the connected state, the second switch S4 is in the disconnected state, and the third switch S5 is in the connected state when the motor 1 is stopped and / or when the motor 1 is powered. Furthermore, the electric vehicle according to this embodiment is capable of recovering energy (storing regenerative energy) in the first power storage device 4 and the second power storage device 5 while the output voltage (Vinv-Vdc2) of the second power storage device 5 is increased while the first switch S3 is in the disconnected state, the second switch S4 is in the connected state, and the third switch S5 is in the disconnected state when the motor 1 is regenerating.

[0036] Furthermore, when the motor 1 is powered, the electric vehicle according to this embodiment is configured such that, if the storage state of the second storage device 5 is equal to or greater than a predetermined value (above a predetermined lower limit value in FIG. 26), the first switch S3 is turned off, the second switch S4 is turned on, and the third switch S5 is turned off, so that the output voltage of the first storage device 4 is lowered while energy is supplied from the first storage device 4 and the second storage device 5 to the inverter 2.

[0037] Furthermore, when the motor 1 is powered, the first switch S3 is in an OFF state, the second switch S4 is in an OFF state, and the third switch S5 is in an ON state, and energy is supplied from the second power storage device 5 to the inverter 2. Specifically, the temperature state of the first power storage device 4 can be determined by the temperature sensor 4b based on the temperature of the first power storage device 4, and when the motor 1 is powered, if the temperature of the first power storage device 4 is equal to or higher than a predetermined value, the supply of energy from the first power storage device 4 is stopped and energy is supplied from the second power storage device 5 to the inverter.

[0038] The start switch 12 is an operating switch that enables the vehicle to run, and after operating the start switch 12, the accelerator operating means 6 is operated to start the motor 1 and make the vehicle run. The monitor 13 is an auxiliary device such as a liquid crystal monitor attached to the vehicle, and is capable of displaying, for example, the vehicle's status (speed, battery status, presence or absence of malfunctions, etc.) and a map from a navigation system.

[0039] 4, this embodiment is provided with detection means 19 consisting of a sensor that detects the rotation speed of motor 1, and is configured so that when the rotation speed of motor 1 detected by detection means 19 is equal to or greater than a predetermined value, a predetermined braking torque corresponding to the amount of operation of regenerative brake operation means 8 is generated by the regenerative brake (particularly in this embodiment, generated only by the regenerative brake). Furthermore, during regeneration of motor 1, the maximum value of the predetermined braking torque is set to the rated torque of motor 1.

[0040] Furthermore, when the rotation speed of motor 1 detected by detection means 19 is less than a predetermined value, braking torque is generated by the mechanical brake (driving wheel mechanical brake 3a) in accordance with the amount of operation of regenerative brake operation means 8. In addition, when the amount of charge of first power storage device 4 is equal to or greater than a predetermined value, braking torque is generated by the mechanical brake (driving wheel mechanical brake 3a) in accordance with the amount of operation of regenerative brake operation means 8.

[0041] Fig. 5 shows changes in each parameter when the accelerator operation means 6 and the regenerative brake operation means 8 are operated after the start switch 12 is turned on in the electric vehicle according to the above embodiment. In this embodiment, charging begins after the start switch 12 is turned on, and the second power storage device 5 stores electricity when the motor 1 is stopped or in power running. Note that "FCCNO" (function circuit control number) in the table in the same figure corresponds to the "FCCNO" shown in Figs. 4, 18, and 19.

[0042] Next, the control (main control) of the electric vehicle according to this embodiment will be described with reference to the flowchart of FIG. First, in S1, it is determined whether or not start switch 12 is turned on. If it is determined that start switch 12 is turned on, it is determined in S2 whether or not the state of charge (Soc1) of first power storage device 4 is greater than a predetermined lower limit (see FIG. 25). If it is determined that the state of charge (Soc1) is greater than the predetermined lower limit, request processing (S3), motor control (S4), and mechanical brake control (S5) are performed in this order.

[0043] Next, the required characteristics of the electric vehicle according to this embodiment will be described with reference to FIGS. The relationship between the driving torque and braking torque at the driving wheels Ta and the vehicle speed has the characteristics shown in Figure 7, and the relationship between the motor torque at the driving wheels Ta and the rotation speed (ω) of the motor 1 has the characteristics shown in Figure 8. In particular, in Figure 7, when traveling at high speed, the driving torque gradually decreases with the vehicle speed, while the braking torque remains constant. In Figure 8, the positive side (upper half) of the vertical axis indicates the driving torque corresponding to the amount of operation of the accelerator operation means 6, and the negative side (lower half) of the vertical axis indicates the braking torque corresponding to the amount of operation of the regenerative brake operation means 8. The symbol Tm1 in the figure indicates the rated torque of the motor 1.

[0044] The relationship between the braking torque at the driven wheel Tb and the vehicle speed has the characteristics shown in FIG. 9, and the relationship between the braking torque at the driven wheel Tb (mechanical braking torque (Tbmf)) and the rotation speed (ω) of the motor 1 has the characteristics shown in FIG. 10. Note that, since FIGS. 9 and 10 show the characteristics of the driven wheel Tb, only the characteristics (braking torque) on the negative side (lower half) of the vertical axis are shown.

[0045] Next, control (request processing control) of the electric vehicle according to this embodiment will be described with reference to the flowchart of FIG. First, in S1, it is determined whether the regenerative system is normal or not based on the presence or absence of a fault signal. If it is determined that there is no fault signal, it is determined in S2 whether the accelerator operation means 6 is being operated (whether the accelerator operation amount Ap is greater than 0). If it is determined that the accelerator operation means 6 is being operated, the process proceeds to S5, where the motor torque (Tm) corresponding to the operation amount of the accelerator operation means 6 is calculated based on Table 1 shown in FIG. 12.

[0046] After the calculation in S5, the process proceeds to S9, where a mechanical braking torque (Tbmr) corresponding to the amount of operation of the regenerative brake operation means 8 is calculated based on Table 5 shown in Fig. 16, and then the process proceeds to S13, where a mechanical braking torque (Tbmf) corresponding to the amount of operation of the mechanical brake operation means 7 is calculated based on Table 6 shown in Fig. 17. The mechanical braking torque (Tbmr) calculated in S9 is used as the braking torque of the driving wheel Ta, and the mechanical braking torque (Tbmf) calculated in S13 is used as the braking torque of the driven wheel Tb.

[0047] If it is determined in S2 that the accelerator operation means is not being operated, then in S3 it is determined whether regeneration of the motor 1 is possible. This determination is made if the state of charge (Soc1) of the first power storage device 4 is equal to or less than a predetermined upper limit (see FIG. 27) and the motor rotation speed is equal to or greater than ω1 (see FIG. 8). If it is determined that regeneration of the motor 1 is possible, then in S4 it is determined whether the state of charge (Soc2) of the second power storage device 5 is greater than a predetermined upper limit (see FIG. 26).

[0048] If it is determined in S4 that the state of charge (Soc2) of the second power storage device 5 is greater than a predetermined upper limit (see FIG. 26), the process proceeds to S6, where a motor torque (Tm) corresponding to the amount of operation of the regenerative brake operation means 8 is calculated based on Table 2 shown in FIG. 13. Here, in calculating the motor torque (Tm) based on Table 2, if the rotation speed of the motor 1 is equal to or less than a predetermined rotation speed (ω2) shown in FIG. 8, a correction of Tm=Tm(ω-ω1) / (ω2-ω1) is made. After the calculation in S6, the process proceeds to S10, where a mechanical braking torque (Tbmr) corresponding to the amount of operation of the regenerative brake operation means 8 is calculated based on Table 4 shown in FIG. 15, and then the above-mentioned S13 is sequentially performed.

[0049] Furthermore, if it is determined in S4 that the state of charge (Soc2) of the second power storage device 5 is not greater than a predetermined upper limit (see FIG. 26), the process proceeds to S7, where the motor torque (Tm) corresponding to the amount of operation of the regenerative brake operation means 8 is calculated based on Table 3 shown in FIG. 14. Here, in calculating the motor torque (Tm) based on Table 3, as with Table 2, if the rotation speed of the motor 1 is equal to or less than the predetermined rotation speed (ω2) shown in FIG. 8, a correction of Tm=Tm(ω-ω1) / (ω2-ω1) is made. After the calculation in S7, the mechanical braking torque (Tbmr) is set to 0 in S11, and then the above-mentioned S13 is performed.

[0050] On the other hand, if it is determined in S1 that a fault signal is present or if it is determined in S3 that regeneration is not possible, the process proceeds to S8, where the motor torque (Tm) is set to 0, and then the process proceeds to S12, where the mechanical braking torque (Tbmr) corresponding to the amount of operation of the regenerative brake operation means 8 is calculated based on Table 5 shown in Fig. 16. As a result, when it is determined that there is a fault in the regenerative system or that regeneration is not possible, braking torque can be generated by the mechanical brake (drive wheel mechanical brake 3a) according to the amount of operation of the regenerative brake operation means 8. After the calculation in S12, the already-mentioned S13 is performed.

[0051] Next, control (motor control) of the electric vehicle according to this embodiment will be described with reference to the flowcharts of FIGS. 18a and 18b. First, in S1, it is determined whether the regenerative system is normal or not based on the presence or absence of a fault signal. If it is determined that there is no fault signal, it is determined in S2 whether the accelerator operation means 6 is being operated (whether the accelerator operation amount Ap is greater than 0). If it is determined that the accelerator operation means 6 is being operated, it is determined in S3 whether the storage state (Soc2) of the second storage device 5 is greater than a predetermined lower limit value (see Figure 26).

[0052] Then, if it is determined in S3 that the state of charge (Soc2) of the second storage device 5 is not greater than a predetermined lower limit (see Figure 26), the process proceeds to S10, where FCC (function circuit control) is set to 1, and if it is determined in S3 that the state of charge (Soc2) of the second storage device 5 is greater than a predetermined lower limit (see Figure 26), the process proceeds to S4, where it is determined whether the rotation speed (ω) of the motor 1 is smaller than ω3.

[0053] If it is determined in S4 that the rotation speed (ω) of the motor 1 is not smaller than ω3, the process proceeds to S11, where FCC is set to 2, and if it is determined in S4 that the rotation speed (ω) of the motor 1 is smaller than ω3, the process proceeds to S5, where it is determined whether or not the temperature of the first power storage device 4 is smaller than a predetermined value. If it is determined in S5 that the temperature of the first power storage device 4 is not smaller than the predetermined value, the process proceeds to S13, where FCC is set to 4, and if it is determined in S5 that the temperature of the first power storage device 4 is smaller than the predetermined value, the process proceeds to S6, where it is determined whether or not the accelerator operation amount Ap is smaller than a predetermined value.

[0054] Thereafter, if it is determined in S6 that the accelerator operation amount Ap is not smaller than the predetermined value, the process proceeds to S11, where FCC = 2 is set, and if it is determined in S6 that the accelerator operation amount Ap is smaller than the predetermined value, the process proceeds to S12, where FCC = 3. On the other hand, if it is determined in S2 that the accelerator operation means 6 is not being operated, the process proceeds to S7, where it is determined whether regeneration of the motor 1 is possible, and if it is determined that regeneration is possible, the process proceeds to S8, where it is determined whether the state of charge (Soc2) of the second power storage device 5 is greater than a predetermined upper limit value.

[0055] If it is determined in S8 that the state of charge (Soc2) of the second storage device 5 is greater than the predetermined upper limit, the process proceeds to S14, where FCC is set to 5, and if it is determined in S8 that the state of charge (Soc2) of the second storage device 5 is not greater than the predetermined upper limit, the process proceeds to S15, where FCC is set to 6. Furthermore, if it is determined in S7 that regeneration of the motor 1 is not possible, the process proceeds to S9, where it is determined whether the state of charge (Soc2) of the second storage device 5 is equal to or less than a charge determination value.

[0056] If it is determined in S9 that the state of charge (Soc2) of the second storage device 5 is equal to or less than the charging determination value, the process proceeds to S16, where FCC is set to 7, and if it is determined in S9 that the state of charge (Soc2) of the second storage device 5 is greater than the charging determination value, the process proceeds to S17, where FCC is set to 8. Note that even if it is determined in S1 that a fault signal is present, the process proceeds to S17, where FCC is set to 8.

[0057] After modes (FCC) 1 to 8 are determined as described above, a determination is made in S18 as to whether the mode (FCC) determined in this process has changed from the mode (FCCO) determined in the previous process, and if it is determined that there has been no mode change, the process proceeds to S19, where the FCC determined in S10 to S17 is maintained, and if it is determined that there has been a mode change, the process proceeds to S20, where FCCNO = 8. Thereafter, circuit control according to FCCNO is performed in S21, and charging control according to FCCNO is performed in S22, and then the mode (FCC) determined in this process is stored in FCCO in S23, and inverter control is performed in S24.

[0058] Here, the control of S21 is performed based on the control table of Fig. 19. The control content according to this control table will be explained below. When FCCNO=1, switches S1 and S2 of semiconductor switch elements 10a and 10b are duty controlled during power running, so that power converter 10 reduces the output voltage of first power storage device 4, and also first switch S3 is connected (on state), second switch S4 is disconnected (off state), and third switch S5 is disconnected (off state). When FCCNO=1, current control of inverter 2 is performed based on table A shown in FIG.

[0059] According to Table A, on the premise that the current control of the inverter 2 is performed by PWM control (pulse width modulation), the DC voltage of the inverter 2 can be controlled in accordance with the rotation speed (ω) of the motor 1, as shown in Fig. 20. Note that Tables B to E, which will be described later, also assume that the current control of the inverter 2 is performed by PWM control.

[0060] When FCCNO=2, switches S1 and S2 of semiconductor switch elements 10a and 10b are duty controlled during power running, so that power converter 10 reduces the output voltage of first power storage device 4, and also first switch S3 is brought into a cut-off state (off state), second switch S4 is brought into a connective state (on state), and third switch S5 is brought into a cut-off state (off state). When FCCNO=2, current control of inverter 2 is performed based on table B shown in FIG.

[0061] When FCCNO=3, switches S1 and S2 of semiconductor switch elements 10a and 10b are duty controlled during powering and charging, so that power converter 10 reduces the output voltage of first power storage device 4, and also first switch S3 is connected (on state), second switch S4 is disconnected (off state), and third switch S5 is connected (on state). When FCCNO=3, current control of inverter 2 is performed based on table C shown in FIG.

[0062] When FCCNO=4, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are turned off (the power converter 10 is turned off), the first switch S3 and the second switch element S4 are turned off (off), and the third switch S5 is turned on (on). When FCCNO=4, the current control of the inverter 2 is performed based on table C shown in FIG.

[0063] When FCCNO=5, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are duty-controlled during regeneration to boost the voltage, and the first switch S3 is in a connected state (on state), the second switch S4 is in a disconnected state (off state), and the third switch S5 is in a disconnected state (off state). When FCCNO=5, the current control of the inverter 2 is performed based on table D shown in FIG.

[0064] When FCCNO=6, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are duty-controlled during regeneration to boost the voltage, and the first switch S3 is in a cutoff state (off state), the second switch S4 is in a connective state (on state), and the third switch S5 is in a cutoff state (off state). When FCCNO=6, the current control of the inverter 2 is performed based on table E shown in FIG.

[0065] When FCCNO=7, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are duty-controlled to step down the voltage when stopped, and the first switch S3 is in a connected state (on state), the second switch S4 is in a disconnected state (off state), and the third switch S5 is in a connected state (on state). When FCCNO=7, the current control of the inverter 2 is performed based on table C shown in FIG.

[0066] When FCCNO=8, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are turned off (the power converter 10 is turned off), and the first switch S3, the second switch S4, and the third switch S5 are turned off. When FCCNO=9, the switches S1 and S2 of the semiconductor switch elements 10a and 10b are duty controlled, and the first switch S3, the second switch S4, and the third switch S5 are turned off.

[0067] According to the electric vehicle of the above embodiment, when the motor 1 is stopped and / or powered, the first switch S3 is connected, the second switch S4 is disconnected, and the third switch S5 is connected, and energy is supplied from the first power storage device 4 to the second power storage device 5 while the output voltage (Vdc1) of the first power storage device 4 is reduced, so that the second power storage device 5 can be charged when the motor 1 is stopped and / or powered. Therefore, it is possible to reduce the size of the second power storage device 4 and prevent the second power storage device 5 from running out of energy while the vehicle is running, and the life of the first power storage device 4 can be improved.

[0068] In particular, the electric vehicle according to this embodiment is capable of determining the state of charge of the second storage battery 5 based on the voltage of the second storage battery 5, and when the state of charge of the second storage battery 5 is equal to or lower than a predetermined value, the output voltage of the first storage battery 4 is reduced while energy is supplied to the second storage battery 5, so that the second storage battery 5 can be charged according to the state of charge of the second storage battery 5. Furthermore, during regeneration of the motor 1, the first switch S3 is in an interrupted state, the second switch S4 is in an connected state, and the third switch S5 is in an interrupted state, and energy (regenerative energy) is recovered by the first storage battery 4 and the second storage battery 5, so that the regenerative energy can be recovered efficiently.

[0069] Furthermore, when the motor 1 is powered, the first switch S3 is in an off state, the second switch S4 is in an on state, and the third switch S5 is in an off state, and energy is supplied to the inverter 2 from the first storage device 4 and the second storage device 5 while the output voltage of the first storage device 4 is reduced, so that energy can be supplied to the inverter 2 from both the first storage device 4 and the second storage device 5 to run the electric vehicle.

[0070] Furthermore, when the motor 1 is powered, the first switch S3 is in an OFF state, the second switch S4 is in an OFF state, and the third switch S5 is in an ON state, and energy is supplied from the second power storage device 5 to the inverter 2, so that the electric vehicle can run by supplying energy from the second power storage device 5 while stopping the first power storage device 4. In particular, the temperature state of the first power storage device 4 can be determined based on the temperature of the first power storage device 4, and when the temperature of the first power storage device 4 is equal to or higher than a predetermined value, energy is supplied from the second power storage device 5 to the inverter 2, so that overheating of the first power storage device 4 can be avoided while the electric vehicle can run by supplying energy from the second power storage device 5.

[0071] In addition, the storage device is configured to have a first storage device 4 having high-capacity characteristics and a second storage device 5 having high-output characteristics, and a power converter having a function of reducing voltage during power running is connected to the first storage device 4, and a circuit is provided in which the second storage device 5 is connected in series between the reactor 10c of the power converter 10 and the inverter 2, and energy is recovered to the first storage device 4 and the second storage device 5 using this circuit during regeneration of the motor 1.Therefore, during regeneration of the motor 1, the rated torque can be generated by regenerative braking alone up to a higher motor rotation speed than the motor rotation speed at which the rated torque can be generated by the first storage device 4 alone.

[0072] Furthermore, when the motor is powered, the output voltage of the first power storage device 4 is stepped down and energy is supplied to the inverter 2 from the first power storage device 4 and the second power storage device 5, so that step-up and step-down are possible in combination with the step-up function of the second power storage device 5. Therefore, by stepping up and down the output voltage of the first power storage device 4, it is possible to adjust it to match the DC voltage setting of the inverter 2, so that even if the set value of the DC voltage of the inverter 2 changes, a storage battery with a standard voltage can be used, preventing an increase in manufacturing costs.

[0073] In particular, according to this embodiment, during power running, by duty controlling the switches S1 and S2 in the semiconductor switch elements 10a and 10b of the power converter 10, it is possible to optimally control the inverter DC voltage of the motor 1 to increase or decrease the voltage relative to the voltage of the first power storage device 4. Furthermore, since the power running energy is shared and supplied by the first power storage device 4 and the second power storage device 5, the current of the first power storage device 4 is smaller than when the same amount of power running energy is supplied by the first power storage device 4 alone, and even when the power running energy is large, the current of the first power storage device 4 can be reduced, thereby improving the life of the first power storage device 4.

[0074] However, since the first storage battery 4 has higher voltage characteristics than the second storage battery 5, the output voltage of the first storage battery 4 can be stepped down to supply energy to the second storage battery 5. Furthermore, since the amount of energy in the first storage battery 4 when fully charged is greater than the amount of energy in the second storage battery 5 when fully charged, energy can be smoothly supplied from the first storage battery 4 to the second storage battery 5. Furthermore, since the first storage battery 4 is formed as a replaceable cassette-type battery, the first storage battery 4 can be replaced in a short time when necessary, allowing a stable supply of energy from the first storage battery 4 to the second storage battery 5.

[0075] Although the present embodiment has been described above, the present invention is not limited to this. For example, the first switch S3, the second switch S4, and the third switch S5 may be of other types of switches, or additional switches may be added. Furthermore, the semiconductor switch elements may be IGBTs instead of MOSFETs. Furthermore, the present invention may be applied to vehicles that do not include a monitor 13, or to three-wheeled or four-wheeled vehicles such as buggies. [Industrial Applicability]

[0076] Mo When the motor is powered, the first switch is in a connected state, the second switch is in a disconnected state, and the third switch is in a connected state, and the output voltage of the first power storage device is reduced while the first power storage device is supplied with power. Through a power converter Second power storage device and inverterThe present invention can be applied to electric vehicles that have different external shapes or that have other functions added thereto, as long as the electric vehicles supply energy to the vehicle. [Explanation of symbols]

[0077] 1 motor 2 inverters 3a Drive wheel mechanical brake 3b Driven wheel mechanical brake 4. First storage device 4a Voltage detection sensor 4b Temperature detection sensor 5 Second storage device 5a Voltage detection sensor 6 Accelerator operation means 7 Mechanical brake operation means 8. Regenerative braking operation means 9 Brake Actuator 10 Power Converter 10a, 10b Semiconductor switch element (MOSFET) 10c reactor (coil) 11 ECU 12 Start switch 13 Monitor (auxiliary device) 14, 15 Semiconductor switching element (MOSFET) 16 Inverter control unit 17 Circuit control section 18 Mechanical brake control unit 19 Detection methods Ta drive wheel Tb driven wheel S3 First switch S4 Second switch S5 3rd switch Ca smoothing capacitor Cb smoothing capacitor Vdc1 First storage device (battery) voltage Vdc2 Second storage device (capacitor) voltage Vinv Inverter DC voltage V1 S2 terminal average voltage

Claims

1. a motor capable of power running; an inverter capable of converting direct current to alternating current; An electric vehicle having a first power storage device having high-capacity characteristics; a second power storage device having high-output characteristics; a power converter having a function of stepping down during power running; a circuit in which the power converter having a function of stepping down voltage during power running is connected to the first power storage device, and the second power storage device is connected in series between a reactor of the power converter and the inverter; a first switch that forms a circuit that connects the power converter and the inverter without passing through the second power storage device; a second switch forming a circuit connecting the power converter and the inverter via the second power storage device; a third switch that forms a circuit connecting the second power storage device and ground; Equipped with an inverter for supplying energy from the first power storage device to the inverter through the power converter while reducing an output voltage of the first power storage device; and a power converter for supplying energy from the first power storage device to the inverter through the power converter while reducing an output voltage of the first power storage device.

2. 2. The electric vehicle according to claim 1, wherein the state of charge of the second storage device can be determined based on the voltage of the second storage device, and when the state of charge of the second storage device is equal to or lower than a predetermined value, energy is supplied to the second storage device while reducing the output voltage of the first storage device.

3. 3. The electric vehicle according to claim 1, wherein the motor is capable of power running and regeneration, the power converter has a function of reducing voltage during power running and a function of increasing voltage during regeneration, and during regeneration of the motor, the first switch is in a cut-off state, the second switch is in a connected state, and the third switch is in a cut-off state, so that an output voltage of the second power storage device is increased while energy is recovered by the first power storage device and the second power storage device.

4. 4. The electric vehicle according to claim 1, wherein, when the motor is powered, the first switch is in an interrupted state, the second switch is in an connected state, and the third switch is in an interrupted state, and energy is supplied to the inverter from the first storage device and the second storage device while reducing the output voltage of the first storage device.

5. 5. The electric vehicle according to claim 1, wherein, when the motor is powered, the first switch is in an interrupted state, the second switch is in an interrupted state, and the third switch is in a connected state, and energy is supplied from the second storage device to the inverter.

6. 6. The electric vehicle according to claim 5, wherein a temperature state of the first power storage device can be determined based on the temperature of the first power storage device, and when the temperature of the first power storage device is equal to or higher than a predetermined value during power running of the motor, energy is supplied from the second power storage device to the inverter.

7. 7. The electric vehicle according to claim 1, wherein the first power storage device has higher voltage characteristics than the second power storage device.

8. 8. The electric vehicle according to claim 1, wherein the amount of energy in the first power storage device when fully charged is greater than the amount of energy in the second power storage device when fully charged.

9. 9. The electric vehicle according to claim 1, wherein the first power storage device is a replaceable cassette-type power storage device.

10. 10. The electric vehicle according to claim 1, wherein the first power storage device is a high-capacity lithium-ion battery or a high-capacity nickel-metal hydride battery, and the second power storage device is any one of a high-output lithium-ion battery, a high-output nickel-metal hydride battery, a lithium-ion capacitor, or an electric double layer capacitor.

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