Electric moving body

Abstract

To provide an electric moving body capable of suppressing current flowing between two inverters.SOLUTION: An electric moving body 1 moving by driving a motor 6 with an inverter 101 and an inverter 102 comprises: a switch 107 connecting a battery 103 and a DC part of an inverter 101; a switch 108 connecting the battery 103 and a battery 104; an electric moving body side connection part 111 supplying DC electric power to the DC part of the inverter 101 from the outside; and a controller 112. The battery 104 and a DC part of the inverter 102 are connected with each other, and the controller 112 forces the switch 107 to turn on and the switch 108 to turn off when the electric moving body 1 is in a traveling mode, and forces the switch 107 to turn off and the switch 108 to turn on when the moving body side connection part 111 is connected with an external charging facility and in a mode for charging the battery 103 and the battery 104.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric vehicle equipped with a rapid charging function. [Background technology]

[0002] In recent years, the spread (electrification) of electric vehicles (EVs) has been accelerating worldwide. In addition to EVs, attempts are being made to electrify ships and aircraft as electric vehicles. In addition, railway vehicles that run on non-electrified line sections using electricity stored in batteries, and other electrified agricultural machinery are also being developed. For example, EVs run using energy stored in on-board batteries, so the on-board batteries need to be charged at designated power supply facilities. Therefore, there is a demand for charging systems that can efficiently charge EVs while increasing the number of opportunities to charge.

[0003] To configure such a charging system, a system concept has been proposed in Patent Document 1 and Non-Patent Document 1 that links DC power generation (direct current power generation) using renewable energy with an EV equipped with a built-in rapid charging function. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6570779 [Non-patent literature]

[0005] [Non-Patent Document 1] Kazumasa Ide et al., "Proposal of a system concept to link DC power generation using renewable energy with electric vehicles equipped with quick charging functions," Journal of Electrical Engineering D, Vol. 140, No. 4, pp. 289-294, 2020 Summary of the Invention [Problem to be solved by the invention]

[0006] As an EV with a built-in quick charging function, there is a configuration in which one motor is driven by two inverters, as disclosed in FIG. 6(b) of Patent Document 1 and FIG. 4(b) of Non-Patent Document 1. However, in the case of this configuration, the AC terminals and DC terminals of the two inverters are connected to each other when the EV is running, so a loop circuit is generated between the two inverters, and if there is a voltage difference between the voltages that the two inverters output to their respective AC terminals, a current flows through the loop circuit. As a result, there is a risk that the inverter will stop due to an overcurrent.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide an electric vehicle capable of suppressing the current flowing between two inverters. [Means for solving the problem]

[0008] In order to achieve the above object, the electric vehicle of the present invention is an electric vehicle that includes a first storage device, a second storage device, a first power conversion device, and a second power conversion device, and moves by driving an electric motor with the first power conversion device and the second power conversion device, the electric vehicle includes a first switch that connects the first storage device and the DC part of the first power conversion device, a second switch that connects the first storage device and the second storage device, a DC connection part that supplies DC power from an external source to the DC part of the first power conversion device, and a controller, the second storage device and the DC part of the second power conversion device are connected, and the controller turns the first switch ON and the second switch OFF when the electric vehicle is in a mode in which the electric vehicle runs, and turns the first switch OFF and the second switch ON when the DC connection part is connected to an external charging facility and is in a mode in which the first storage device and the second storage device are charged. Other aspects of the present invention will be described in the embodiments described later. Effect of the Invention

[0009] According to the present invention, the current flowing between the two inverters can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of an electric vehicle according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a configuration of a controller according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing a configuration of a torque command correction calculation means according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an operation pattern of a switch control means according to the first embodiment. [Diagram 5] 5 is a diagram illustrating an example of the operation of a torque command correction calculation means according to the first embodiment. FIG. [Figure 6] 4 is a diagram showing a circuit configuration when an electric vehicle according to the first embodiment is in a traveling mode. FIG. [Figure 7] 4 is a diagram showing a circuit configuration when an electric vehicle according to the first embodiment is in a charging mode. FIG. [Figure 8] FIG. 11 is a diagram showing a configuration of an electric vehicle according to a second embodiment. [Figure 9] FIG. 11 is a diagram illustrating a configuration of a controller according to a second embodiment. [Figure 10] FIG. 11 is a diagram showing an operation pattern of a switch control means according to the second embodiment. [Figure 11] FIG. 11 is a diagram showing a circuit configuration when an electric vehicle according to a second embodiment is in a traveling mode. [Figure 12] FIG. 11 is a diagram showing a circuit configuration when an electric vehicle according to a second embodiment is in a charging mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of an electric vehicle according to the present invention will be described with reference to the drawings, taking an EV as an example. First Embodiment 1 is a diagram showing the configuration of an electric vehicle according to the first embodiment. The electric vehicle 1 of this embodiment has an inverter 101, an inverter 102, a battery 103, a battery 104, a transformer 105, a motor 106, a switch 107, a switch 108, a switch 109, a switch 110, an electric vehicle side connection unit 111, and a controller 112.

[0012] The DC side of the inverter 101 is connected to the electric vehicle side connection unit 111 and the switch 107, and the AC side of the inverter 101 is connected to the switch 109. The DC side of the inverter 102 is connected to the battery 104 and the switch 108, and the AC side of the inverter 102 is connected to the switch 110. The battery 103 is connected to the switches 107 and 108. The transformer 105 is connected to the switches 109 and 110. The motor 106 is connected to the switches 109 and 110.

[0013] Switches 107 and 108 are switches that select either an ON or OFF state. Switch 109 is a switch that selects either a state in which the inverter 101 is connected to the transformer 105 or a state in which the inverter 101 is connected to the motor 106. Switch 110 is a switch that selects either a state in which the inverter 102 is connected to the transformer 105 or a state in which the inverter 102 is connected to the motor 106.

[0014] Controller 112 receives a torque command, a charging command, an operating mode command, and detected battery voltage values ​​of batteries 103 and 104 as inputs, and outputs inverter control commands to inverters 101 and 102, and switch control commands to switches 107, 108, 109, and 110.

[0015] The power supply system 2 has a power supply system side connection unit 201 and a DC bus 202. Although not illustrated here, the DC bus 202 receives a predetermined DC voltage from a power generation system such as a solar power generation system, and supplies the predetermined DC voltage to the power supply system side connection unit 201.

[0016] When the batteries 103 and 104 of the electric vehicle 1 are charged, the power supply system side connection unit 201 and the electric vehicle side connection unit 111 are connected, and power is supplied from the power supply system 2 to the electric vehicle 1. On the other hand, when the electric vehicle 1 runs, the power supply system side connection unit 201 and the electric vehicle side connection unit 111 are not connected, and the electric vehicle 1 runs by driving the motor 106 using the energy stored in the batteries 103 and 104.

[0017] 2 is a diagram showing the configuration of the controller 112 according to the first embodiment. The controller 112 has a torque command correction calculation means 1121, a command switching means 1122, and a switch control means 1123.

[0018] A torque command correction calculation means 1121 receives a torque command and the detected battery voltage values ​​of the batteries 103 and 104, and outputs a torque command to the inverter 101 and the inverter .

[0019] The command switching means 1122 receives as input a torque command, a charge command, and an operation mode command for the inverters 101 and 102, and outputs an inverter control command to the inverters 101 and 102. When the operation mode command is a traveling mode, the electric vehicle 1 is traveling, so a torque command to the inverters 101 and 102 is output as an inverter control command to the inverters 101 and 102. On the other hand, when the operation mode command is a charging mode, the batteries 103 and 104 of the electric vehicle 1 are charging, so a charge command is output as an inverter control command to the inverters 101 and 102.

[0020] The switch control means 1123 receives an operation mode command and outputs operation commands to the switches 107, 108, 109, and 110. The operation of the switch control means 1123 will be described in detail later.

[0021] 3 is a diagram showing the configuration of the torque command correction calculation means 1121 according to the first embodiment. The torque command correction calculation means 1121 has a subtractor 11211, a gain 11212, an adder 11213, and a subtractor 11214.

[0022] The subtractor 11211 receives the battery voltage detection values ​​of the battery 103 and the battery 104, calculates a difference between them, and outputs it as a battery voltage difference value. The gain 11212 multiplies the battery voltage difference value by a predetermined gain and outputs the result as a torque command correction amount. The adder 11213 receives the torque command and the torque command correction amount output by the gain 11212, calculates an added value thereof, and outputs it as a torque command to the inverter 101. The subtractor 11214 receives the torque command and the torque command correction amount output by the gain 11212, calculates a difference between them, and outputs it as a torque command to the inverter 102.

[0023] 4 is a diagram showing an operation pattern of the switch control means 1123 according to the first embodiment. When the operation mode command is a traveling mode, the switch control means 1123 outputs an ON command to the switch 107, outputs an OFF command to the switch 108, outputs a command to the switch 109 to connect to the motor 106, and outputs a command to the switch 110 to connect to the motor 106. When the operation mode command is a charging mode, the switch control means 1123 outputs an OFF command to the switch 107, outputs an ON command to the switch 108, outputs a command to the switch 109 to connect to the transformer 105, and outputs a command to the switch 110 to connect to the transformer 105.

[0024] 5 is a diagram showing an example of the operation of the torque command correction calculation means 1121 according to the first embodiment. Until time T1, the battery voltage detection values ​​of the battery 103 and the battery 104 match, and therefore the torque commands to the inverter 101 and the inverter 102 match.

[0025] Here, assume that the remaining capacity of battery 104 decreases relative to the remaining capacity of battery 103, and accordingly, from time T1, the battery voltage detection value of battery 104 decreases relative to the battery voltage detection value of battery 103. Then, the torque command to inverter 101 increases, and the torque command to inverter 102 decreases. As a result, the power discharged from battery 104 decreases relative to the power discharged from battery 103, so that the difference between the remaining capacities of batteries 103 and 104 is controlled to be small. Then, the difference between the battery voltage detection values ​​of batteries 103 and 104 also decreases, and the voltage detection values ​​of batteries 103 and 104 match at time T2.

[0026] In this way, when a difference occurs between the battery voltage detection values ​​of battery 103 and battery 104, the torque commands to inverters 101 and 102 are corrected in a direction to reduce the difference, so that the battery voltage detection values ​​of battery 103 and battery 104 are always maintained to be the same while the electric vehicle 1 is traveling.

[0027] 6 is a diagram showing a circuit configuration when the electric vehicle 1 according to the first embodiment is in a traveling mode. As described above, when the electric vehicle 1 is traveling, the electric vehicle side connection unit 111 is not connected to the power supply system 2. Also, the switch 107 is ON, the switch 108 is OFF, the switch 109 is connected to the motor 106, and the switch 110 is connected to the motor 106. Therefore, the inverter 101 is supplied with DC power from the battery 103 and drives the motor 106 according to an inverter control command from the controller 112. Similarly, the inverter 102 is supplied with DC power from the battery 104 and drives the motor 106 according to an inverter control command from the controller 112.

[0028] That is, in this mode, the switch 108 is OFF, and therefore no loop circuit is generated between the inverters 101 and 102. Therefore, no current flows between the inverters 101 and 102, and there is no risk of the inverters 101 and 102 stopping due to an overcurrent flowing between the inverters 101 and 102.

[0029] Also, when the electric vehicle 1 is in a traveling mode, the inverter control command is given as a torque command as described in the description of Fig. 2, and the torque command is corrected in accordance with the battery voltage detection values ​​of the batteries 103 and 104 as described in the description of Fig. 3. Therefore, the inverter control command given to the inverters 101 and 102 is a torque command corrected so that the battery voltage detection values ​​of the batteries 103 and 104 always match.

[0030] As a result, the battery voltages of the battery 103 and the battery 104 are always maintained equal while the electric vehicle 1 is traveling. The purpose of maintaining the battery voltages of the battery 103 and the battery 104 equal will be described later.

[0031] 7 is a diagram showing a circuit configuration when the electric vehicle 1 according to the first embodiment is in a charging mode. As described above, when the electric vehicle 1 is charging, the electric vehicle side connection unit 111 is connected to the power supply system side connection unit 201, and power is supplied from the power supply system 2 to the electric vehicle 1. In addition, the switch 107 is OFF, the switch 108 is ON, the switch 109 is connected to the transformer 105, and the switch 110 is connected to the transformer 105.

[0032] Therefore, the DC power supplied from the power supply system 2 is converted to three-phase AC power by the inverter 101 and input to the primary side of the transformer 105. The three-phase AC power input to the primary side of the transformer 105 is insulated by the transformer 105, and the voltage level is further converted, and output as three-phase AC power from the secondary side of the transformer 105. The three-phase AC power output from the secondary side of the transformer 105 is converted to DC power by the inverter 102. The DC power is supplied to both the battery 103 and the battery 104, and charges the battery 103 and the battery 104. When the electric vehicle 1 is in a charging mode, the inverter control command is given as a charging command as described in the explanation of FIG. 2.

[0033] Therefore, the inverter control command given to the inverter 101 and the inverter 102 becomes a charging command to operate the inverter 101 and the inverter 102 so as to charge the battery 103 and the battery 104. That is, when the electric vehicle 1 is in a charging mode, the inverter 101, the transformer 105, and the inverter 102 form an insulating DC / DC converter, and the direct current power supplied from the power supply system 2 is DC / DC converted and charged into the battery 103 and the battery 104. As a result, the battery 103 and the battery 104 are charged to a predetermined charge amount.

[0034] Here, the purpose of controlling the battery voltages of the battery 103 and the battery 104 to be equal when the electric vehicle 1 is in a traveling mode will be described. This is to enable the battery 103 and the battery 104 to be connected in parallel by turning on the switch 108 when the electric vehicle 1 is in a charging mode, and to charge the battery 103 and the battery 104 simultaneously. If the battery voltages of the battery 103 and the battery 104 are not equal, turning on the switch 108 may cause an overcurrent to flow between the two batteries due to the voltage difference between the batteries 103 and 104. However, if the battery voltages of the battery 103 and the battery 104 are equal, there is no risk of such an overcurrent flowing.

[0035] Therefore, by always maintaining the battery voltages of the battery 103 and the battery 104 equal when the electric vehicle 1 is in a traveling mode, the battery 103 and the battery 104 can be connected in parallel and charged simultaneously when the electric vehicle 1 is in a charging mode. This eliminates the need to charge the battery 103 and the battery 104 separately, simplifying the charging process.

[0036] With the above configuration, in this embodiment, when the electric vehicle 1 runs, a loop circuit is not generated between the inverters 101 and 102, and it is possible to prevent a current from flowing through the loop circuit. Therefore, it is possible to prevent the inverters 101 and 102 from stopping due to an overcurrent caused by the current.

[0037] Furthermore, when the electric vehicle 1 is to be charged, the batteries 103 and 104 can be connected in parallel and charged simultaneously, which simplifies the charging process.

[0038] In addition, although the circuit configuration in the traveling mode is shown in Fig. 6, the operation mode of the eco mode and the power mode may be adopted in the traveling mode. That is, in the traveling mode in Fig. 6, in the eco mode, the inverter 101 or the inverter 102 supplies power to the motor 106. In the power mode, it is preferable to supply power to the motor 106 from both the inverter 101 and the inverter 102.

[0039] <Embodiment 2> 8 is a diagram showing the configuration of an electric vehicle 3 according to the second embodiment. The electric vehicle 3 of this embodiment has an inverter 101, an inverter 102, a battery 103, a transformer 105, a motor 106, a switch 107, a switch 109, a switch 110, a reactor 113, a reactor 114, an electric vehicle side connection unit 111, and a controller 115. Compared to the electric vehicle 1 of the first embodiment, the electric vehicle 3 of the second embodiment does not have the battery 104 and the switch 108, and the reactor 113 and the reactor 114 are added.

[0040] The DC side of the inverter 101 is connected to the electric vehicle side connection unit 111 and the switch 107, and the AC side of the inverter 101 is connected to the switch 109 via a reactor 113. The DC side of the inverter 102 is connected to the battery 103 and the switch 107, and the AC side of the inverter 102 is connected to the switch 110 via a reactor 114. The battery 103 is connected to the switch 107 and the inverter 102. The transformer 105 is connected to the switch 109 and the switch 110. The motor 106 is connected to the switch 109 and the switch 110.

[0041] The switch 107 is a switch that selects either an ON or OFF state. The switch 109 is a switch that selects either a state in which the inverter 101 is connected to the transformer 105 via the reactor 113 or a state in which the inverter 101 is connected to the motor 106 via the reactor 113. The switch 110 is a switch that selects either a state in which the inverter 102 is connected to the transformer 105 via the reactor 114 or a state in which the inverter 102 is connected to the motor 106 via the reactor 114.

[0042] Controller 115 receives a torque command, a charge command, and an operation mode command as input, and outputs inverter control commands to inverters 101 and 102 and control commands to switches 107, 109, and 110.

[0043] The power supply system 2 has a power supply system side connection unit 201 and a DC bus 202. Although the description of the DC bus 202 is omitted here, a predetermined DC voltage is supplied from a power generation system such as a solar power generation system, and the predetermined DC voltage is supplied to the power supply system side connection unit 201.

[0044] When charging the battery 103 of the electric vehicle 3, the power supply system side connection unit 201 and the electric vehicle side connection unit 111 are connected, and power is supplied from the power supply system 2 to the electric vehicle 3. On the other hand, when the electric vehicle 3 runs, the power supply system side connection unit 201 and the electric vehicle side connection unit 111 are not connected, and the electric vehicle 3 runs by driving the motor 106 using the energy stored in the battery 103.

[0045] 9 is a diagram showing the configuration of the controller 115 according to the second embodiment. The controller 115 has a command switching means 1151 and a switch control means 1152.

[0046] The command switching means 1151 receives as input a torque command, a charge command, and an operation mode command, and outputs an inverter control command to the inverters 101 and 102. When the operation mode command is a traveling mode, the electric vehicle 3 is traveling, so a torque command is output as an inverter control command to the inverters 101 and 102. On the other hand, when the operation mode command is a charging mode, the battery 103 of the electric vehicle 3 is to be charged, so a charge command is output as an inverter control command to the inverters 101 and 102.

[0047] Switch control means 1152 receives an operation mode command and outputs operation commands to switches 107, 109, and 110. The operation of switch control means 1152 will be described in detail later.

[0048] 10 is a diagram showing an operation pattern of the switch control means 1152 according to the second embodiment. When the operation mode command is a traveling mode, the switch control means 1152 outputs an ON command to the switch 107, outputs a command to the switch 109 to connect to the motor 106, and outputs a command to the switch 110 to connect to the motor 106. When the operation mode command is a charging mode, the switch control means 1152 outputs an OFF command to the switch 107, outputs a command to the switch 109 to connect to the transformer 105, and outputs a command to the switch 110 to connect to the transformer 105.

[0049] 11 is a diagram showing a circuit configuration when the electric vehicle 3 according to the second embodiment is in a traveling mode. As described above, when the electric vehicle 3 is traveling, the electric vehicle side connection unit 111 is not connected to the power supply system 2. Also, the switch 107 is ON, the switch 109 is connected to the motor 106, and the switch 110 is connected to the motor 106. Therefore, the inverter 101 is supplied with DC power from the battery 103 and drives the motor 106 according to an inverter control command from the controller 115. Similarly, the inverter 102 is supplied with DC power from the battery 103 and drives the motor 106 according to an inverter control command from the controller 115.

[0050] In this mode, since switch 107 is ON, a loop circuit is generated between inverter 101 and inverter 102, but since this loop circuit includes reactor 113 and reactor 114, even if a voltage difference occurs between the voltages output to the AC terminals of inverter 101 and inverter 102, the current flowing through this loop circuit is suppressed by the effects of reactor 113 and reactor 114. Therefore, the inverter does not stop due to an overcurrent. Note that since the same effect can be obtained with either reactor 113 or reactor 114, a configuration having only reactor 113 or only reactor 114 may be used.

[0051] 12 is a diagram showing a circuit configuration when the electric vehicle 3 according to the second embodiment is in a charging mode. As described above, when the electric vehicle 3 is charging, the electric vehicle side connection unit 111 is connected to the power supply system side connection unit 201, and power is supplied from the power supply system 2 to the electric vehicle 3. In addition, the switch 107 is OFF, the switch 109 is connected to the transformer 105, and the switch 110 is connected to the transformer 105.

[0052] Therefore, the DC power supplied from the power supply system 2 is converted to three-phase AC power by the inverter 101 and input to the primary side of the transformer 105 via the reactor 113. The three-phase AC power input to the primary side of the transformer 105 is insulated by the transformer 105, and the voltage level is further converted, and output as three-phase AC power from the secondary side of the transformer 105. The three-phase AC power output from the secondary side of the transformer 105 is converted to DC power by the inverter 102 via the reactor 114. The DC power is supplied to the battery 103 to charge the battery 103. When the electric vehicle 3 is in a charging mode, the inverter control command is given as a charging command as described in the explanation of FIG. 9. Therefore, the inverter control command given to the inverters 101 and 102 is a charging command that operates the inverters 101 and 102 so as to charge the battery 103.

[0053] That is, when the electric vehicle 3 is in a charging mode, the inverter 101, the reactor 113, the transformer 105, the reactor 114, and the inverter 102 constitute an insulating DC / DC converter, which converts the DC power supplied from the power supply system 2 into DC / DC power and charges the battery 103. As a result, the battery 103 is charged to a predetermined charge level.

[0054] With the above configuration, in this embodiment, the reactor 113 and the reactor 114 are provided in the loop circuit generated between the inverter 101 and the inverter 102 when the electric vehicle 3 runs, thereby making it possible to suppress the current flowing through the loop circuit. As a result, it becomes possible to suppress the inverter 101 and the inverter 102 from stopping due to an overcurrent caused by the current.

[0055] The electric vehicle of this embodiment described above has the following features. The electric vehicle 1 according to the first embodiment is an electric vehicle that includes a first power storage device (e.g., battery 103) and a second power storage device (e.g., battery 104), a first power conversion device (e.g., inverter 101) and a second power conversion device (e.g., inverter 102), and runs (moves) by driving an electric motor (e.g., motor 106) to rotate with the first power conversion device and the second power conversion device. The electric vehicle includes a first switch (e.g., switch 107) that connects the first power storage device and the DC section of the first power conversion device, a second switch (e.g., switch 108) that connects the first power storage device and the second power storage device, a DC connection section (e.g., electric vehicle side connection section 111) that supplies DC power from the outside to the DC section of the first power conversion device, and a controller 112.

[0056] The DC sections of the second storage device and the second power conversion device are connected, and the controller 112 turns the first switch ON and the second switch OFF when the electric vehicle is in a mode in which it runs, and turns the first switch OFF and the second switch ON when the DC connection section is connected to an external charging equipment (e.g., power supply system 2) and in a mode in which the first storage device and the second storage device are charged.

[0057] That is, the electric vehicle 1 that runs by rotating the motor 6 with the inverter 101 and the inverter 102 includes a switch 107 that connects the battery 103 and the DC part of the inverter 101, a switch 108 that connects the battery 103 and the battery 104, an electric vehicle side connection part 111 that supplies DC power from an external part to the DC part of the inverter 101, and a controller 112, and the DC parts of the battery 104 and the inverter 102 are connected, and the controller 112 turns the switch 107 ON and the switch 108 OFF when the electric vehicle 1 is in a mode in which the electric vehicle 1 runs, and turns the switch 107 OFF and the switch 108 ON when the electric vehicle side connection part 111 is in a mode in which the battery 103 and the battery 104 are charged by connecting to an external charging facility. As a result, in this embodiment, a loop circuit is not generated between the inverter 101 and the inverter 102 when the electric vehicle 1 runs, and it is possible to prevent a current from flowing through the loop circuit. Therefore, it is possible to prevent the inverter 101 and the inverter 102 from being stopped due to an overcurrent caused by that current.

[0058] The electric vehicle 1 includes a transformer 105, a third switch (e.g., switch 109) that connects the first power conversion device to either the transformer 105 or the electric motor, and a fourth switch (e.g., switch 110) that connects the second power conversion device to either the transformer 105 or the electric motor. When the electric vehicle 1 is in a traveling mode, the third switch connects the first power conversion device to the electric motor, and the fourth switch connects the second power conversion device to the electric motor. This allows power to be supplied from the inverters 101 and 102 to the motor 106 when in the traveling mode (see FIG. 6).

[0059] In a mode in which the DC connection unit is connected to an external charging facility to charge the first and second power storage devices, the third switch connects the first power conversion device to one end of the transformer, and the fourth switch connects the second power conversion device to the other end of the transformer. This allows batteries 103 and 104 to be charged from power supply system 2 via inverter 101, transformer 105, and inverter 102 in the charging mode (see FIG. 7).

[0060] When the electric vehicle 1 is in a traveling mode, the controller 112 corrects the torque command given to the first power conversion device and the second power conversion device according to the difference between the terminal voltages of the first power storage device and the second power storage device. This allows the battery voltages of the battery 103 and the battery 104 to be always kept equal when the electric vehicle 1 is in a traveling mode, so that the battery 103 and the battery 104 can be connected in parallel and charged simultaneously when the electric vehicle 1 is in a charging mode. This eliminates the need to charge the battery 103 and the battery 104 separately, simplifying the charging operation (see FIG. 5).

[0061] The electric vehicle 1 according to the first embodiment is an electric vehicle that includes a first power storage device (e.g., battery 103) and a second power storage device (e.g., battery 104), a first power conversion device (e.g., inverter 101) and a second power conversion device (e.g., inverter 102), and runs by driving an electric motor (e.g., motor 106) to rotate using the first power conversion device and the second power conversion device. The electric vehicle is also includes a first switch (e.g., switch 107) that connects the first power storage device and the DC section of the first power conversion device, a second switch (e.g., switch 108) that connects the first power storage device and the second power storage device, and a controller 112.

[0062] The controller 112 switches the states of the first switch and the second switch depending on the operation mode of the electric vehicle, that is, the traveling mode and the charging mode. As a result, in this embodiment, when the electric vehicle 1 travels, a loop circuit is not generated between the inverters 101 and 102, and it is possible to prevent a current from flowing through the loop circuit. Therefore, it is possible to prevent the inverters 101 and 102 from stopping due to an overcurrent caused by the current.

[0063] The electric vehicle 3 of the second embodiment is an electric vehicle that includes a power storage device (e.g., a battery 103), a first power conversion device (e.g., an inverter 101), and a second power conversion device (e.g., an inverter 102), and runs by rotating an electric motor (e.g., a motor 106) using the first power conversion device and the second power conversion device. The power storage device is connected to a DC part of the second power conversion device (102), and the electric vehicle includes a first switch (e.g., a switch The inverter circuit includes a first switch (e.g., switch 107), a transformer 105, a third switch (e.g., switch 109) that connects the first power conversion device to either the transformer 105 or the electric motor, a fourth switch (e.g., switch 110) that connects the second power conversion device to either the transformer 105 or the electric motor, and a controller 115. The inverter circuit includes a first switch (e.g., switch 107), a transformer 105, a third switch (e.g., switch 109) that connects the first power conversion device to either the transformer 105 or the electric motor, a fourth switch (e.g., switch 110) that connects the second power conversion device to either the transformer 105 or the electric motor, and a controller 115. The inverter circuit includes a first switch (e.g., switch 107), a transformer 105, a third switch (e.g., switch 109) that connects the first power conversion device to either the transformer 105 or the electric motor, and ....

[0064] With this, by providing the reactors 113 and 114 in a loop circuit generated between the inverters 101 and 102 when the electric vehicle 3 runs, it is possible to suppress the current flowing through the loop circuit. As a result, it is possible to suppress the inverters 101 and 102 from stopping due to an overcurrent caused by that current.

[0065] When the electric vehicle 3 is in a traveling mode, the controller 115 turns on the first switch, the third switch connects the first power conversion device to the electric motor, and the fourth switch connects the second power conversion device to the electric motor. This allows power to be supplied from the inverters 101 and 102 to the motor 106 when in the traveling mode (see FIG. 11).

[0066] The electric vehicle 3 includes a DC connection unit (e.g., electric vehicle side connection unit 111) that supplies DC power from an external source to a DC unit of the first power conversion device, and the controller 115 turns off the first switch, connects the first power conversion device to one end of a transformer with a third switch, and connects the second power conversion device to the other end of the transformer with a fourth switch when the DC connection unit is connected to an external charging facility (e.g., power supply system 2) to charge the power storage device. This allows the battery 103 to be charged from the power supply system 2 via the inverter 101, the transformer 105, and the inverter 102 when in the charging mode (see FIG. 12).

[0067] The present invention can be applied not only to vehicles but also to the electrification of ships and aircraft, as well as to railway vehicles that run on non-electrified line sections using power stored in storage batteries, agricultural machinery, and the like. [Explanation of symbols]

[0068] 1 Electric mobile object 2 Power supply system (external charging equipment) 3 Electric mobile objects 101 inverter (first power conversion device) 102 inverter (second power conversion device) 103 Battery (first power storage device, power storage device) 104 Battery (second power storage device) 105 Transformer 106 Motor (electric motor) 107 Switch (First Switch) 108 Switch (Second Switch) 109 Switch (third switch) 110 Switch (4th Switch) 111 Electric vehicle side connection part (DC connection part) 112 Controller 113 Reactor 114 Reactor 115 Controller 201 Power supply system side connection 202 DC Bus 1121 Torque command correction calculation means 1122 Command switching means 1123 Switch control means 1151 Command switching means 1152 Switch control means 11211 Subtractor 11212 Gain 11213 Adder 11214 Subtractor

Claims

1. An electric vehicle including a first power storage device, a second power storage device, a first power conversion device, and a second power conversion device, the electric vehicle moving by driving an electric motor with the first power conversion device and the second power conversion device, the electric vehicle includes a first switch that connects the first power storage device and a DC unit of the first power conversion device, a second switch that connects the first power storage device and the second power storage device, a DC connection unit that supplies DC power from an external source to the DC unit of the first power conversion device, and a controller; the second power storage device and a DC portion of the second power conversion device are connected to each other, The controller: When the electric vehicle is in a traveling mode, the first switch is turned ON and the second switch is turned OFF; When the DC connection unit is in a mode in which it is connected to an external charging facility to charge the first power storage device and the second power storage device, the first switch is turned OFF and the second switch is turned ON. An electrically powered vehicle.

2. The electric vehicle according to claim 1, The electric vehicle includes a transformer, a third switch that connects the first power conversion device to either the transformer or the electric motor, and a fourth switch that connects the second power conversion device to either the transformer or the electric motor, When the electric vehicle is in a traveling mode, the third switch connects the first power conversion device to the electric motor, and the fourth switch connects the second power conversion device to the electric motor. An electrically powered vehicle.

3. The electric vehicle according to claim 2, When the DC connection unit is in a mode in which it is connected to the external charging facility to charge the first power storage device and the second power storage device, the third switch connects the first power conversion device to one end of the transformer, and the fourth switch connects the second power conversion device to the other end of the transformer. An electrically powered vehicle.

4. The electric vehicle according to claim 2, The controller corrects torque commands to be provided to the first power conversion device and the second power conversion device in accordance with a difference between terminal voltages of the first power storage device and the second power storage device when the electric vehicle is in a traveling mode. An electrically powered vehicle.

5. An electric vehicle including a first power storage device, a second power storage device, a first power conversion device, and a second power conversion device, the electric vehicle moving by driving an electric motor with the first power conversion device and the second power conversion device, the electric vehicle includes a first switch that connects the first power storage device and a DC section of the first power conversion device, a second switch that connects the first power storage device and the second power storage device, and a controller; The electric vehicle, wherein the controller switches states of the first switch and the second switch depending on an operation mode of the electric vehicle, that is, a running mode or a charging mode.

Images