Electric vehicle, control device for electric vehicle, and control method for electric vehicle

Abstract

In the present invention, a dump truck is provided with a control device and a DC-DC converter that outputs electric power to an electric power converter. When switching power supply source for an electric motor from a battery to an overhead wire, the control device operates the DC-DC converter in an overhead wire connection stabilization standby state, and then operates the DC-DC converter in a power feed switch processing state. When switching power supply source for the electric motor from the overhead wire to the battery, the control device switches the state of the DC-DC converter, which is being operated in a power control state, so as to be operated in a voltage control state from the power control state, and, after operating the DC-DC converter in a first overhead wire disengagement preparation state in which the output current to be outputted to the electric power converter is limited to zero, operates the DC-DC converter in a second overhead wire disengagement preparation state in which the output current to be outputted from the DC-DC converter to the electric converter increases toward a target value.

Description

Technical Field

[0001] The present invention relates to an electric vehicle, a control device for an electric vehicle, and a control method for an electric vehicle.

Background Art

[0002] Patent Document 1 discloses a trolleybus as an electric vehicle, which has a power storage device capable of supplying power, a power generation device, and a pantograph for feeding power, and is driven by the power supplied from the power storage device, the power generation device, and the pantograph. When the trolleybus travels within an intersection, it disengages the pantograph from the overhead wire and is driven by the power from the power storage device or the power generation device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor of the present application is considering a trolley-charging type electric vehicle (for example, a trolley-charging type EV dump truck) that does not mount an engine, takes in power required for operation from an overhead wire, and simultaneously charges a battery, and adopts a "trolley-charging type".

[0005] The trolley-charging type electric vehicle travels by power supply from a battery when not connected to an overhead wire. The trolley-charging type electric vehicle travels by power supply from an overhead wire when connected to an overhead wire. In the trolley-charging type electric vehicle, the AC drive system and the battery are connected by a DCDC converter (bidirectional chopper). The trolley-charging type electric vehicle switches the charge and discharge of the battery by a DCDC converter (bidirectional chopper) according to the connection state with the overhead wire.

[0006] In trolley-powered electric vehicles, when switching the power supply source to the electric motor from batteries to overhead lines, and vice versa, it is required to switch the power supply source while minimizing adverse effects on the trolley-powered electric vehicle.

[0007] This invention was made to solve the above problems. Specifically, one of the objectives of this invention is to provide an electric vehicle, a control device for an electric vehicle, and a control method for an electric vehicle that can suppress adverse effects on the electric vehicle when switching the power supply source to the electric motor. [Means for solving the problem]

[0008] To solve the above problems, the electric drive vehicle of the present invention is a trolley-charging electric drive vehicle equipped with an electric motor, a battery and a current collector, which runs using the electric motor driven by power supplied from the battery and / or an overhead line as a power source, and which can charge the battery with power supplied from the overhead line, and includes a power converter that converts the input DC power into AC power and outputs it to the electric motor, and a voltage control state connected to the power converter that takes DC power from the battery as input, converts the voltage, and outputs the DC power of the converted voltage to the power converter, and the DC power from the overhead line A converter capable of operating in any power control state that takes current as input, converts it to voltage, and outputs the converted voltage as DC power to the battery; a current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter; a current collector that can be set to either a conductive state or a non-conductive state between the current collector and the connection point, and an overhead line power supply state in which power is supplied from the overhead line to the power converter via the current collector, or to both the power converter and the converter, by making the connection point conductive; and The device comprises a switch unit for switching to either a state of no overhead line power supply, which interrupts the power supply from the overhead line to the power converter via the current collector by making the connection point between the current collector and the current collector non-conductive, and a control device for controlling the converter and the switch unit, wherein when the power supply source to the motor is switched from the battery to the overhead line, the control device operates the converter in an overhead line connection stabilization waiting state in which the output current output from the converter, which is operating in the voltage control state, to the power converter, and then operates the converter in a power supply switching processing state in which the output current of the converter decreases toward zero, and when the power supply source to the motor is switched from the overhead line to the battery, the converter, which is operating in the power control state, is switched from the power control state to the voltage control state in which the converter is operating, and the converter is operated in a first overhead line disconnection preparation state in which the output current output from the converter to the power converter is limited to zero, and then operates the converter in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value.It is structured in such a way.

[0009] The electric drive vehicle control device of the present invention is applicable to a trolley-charging electric drive vehicle that includes an electric motor, a battery and a current collector, runs on the electric motor driven by power supplied from the battery and / or an overhead line, and can charge the battery with power supplied from the overhead line, wherein the electric drive vehicle includes a power converter that converts the input DC power into AC power and outputs it to the electric motor, and a power converter connected to the power converter that receives DC power from the battery, converts the voltage, and outputs the DC power of the converted voltage to the front A converter capable of operating in either a voltage control state that outputs to the power converter or a power control state that inputs DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery; a current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter; a current collector that can be set to either a conductive state or a non-conductive state between the current collector and the connection point, thereby enabling conductivity between the overhead line and the connection point, and the current from the overhead line to the power converter via the current collector, or the The control device includes a switch unit for switching between a power supply state in which power is supplied to both the power converter and the converter, and a power supply state in which power is not supplied from the overhead line to the power converter via the current collector by making the connection point non-conductive, wherein the control device is configured to control the converter and the switch unit, and when the power supply source to the motor is switched from the battery to the overhead line, the control device operates the converter in a power supply connection stabilization waiting state in which the output current output from the converter, which is operating in the voltage control state, to the power converter is limited, and then operates the converter in a power supply switching processing state in which the output current of the converter decreases toward zero, and when the power supply source to the motor is switched from the overhead line to the battery, the converter, which is operating in the power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first power line disconnection preparation state in which the output current output to the power converter is limited to zero,The converter is configured to operate in a second overhead line disconnection preparation state, where the output current output from the converter to the power converter increases toward a target value.

[0010] The electric drive vehicle control method of the present invention is applicable to a trolley-charging electric drive vehicle equipped with an electric motor, a battery and a current collector, which runs using the electric motor driven by power supplied from the battery and / or an overhead line as a power source, and which can charge the battery with power supplied from the overhead line, wherein the electric drive vehicle includes a power converter that converts the input DC power into AC power and outputs it to the electric motor, and a power converter connected to the power converter that takes DC power from the battery as input, converts the voltage, and converts the DC power of the converted voltage A converter capable of operating in either a voltage control state that outputs to the power converter or a power control state that receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery; a current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter; and a current collector that can be set to either a conductive state or a non-conductive state between the current collector and the connection point, thereby enabling conductivity between the overhead line and the connection point, allowing power to be transmitted from the overhead line through the current collector to the power converter, or The device comprises a switch unit for switching between an overhead line power supply state, which supplies power to both the power converter and the converter, and an overhead line power non-supply state, which disconnects the power supply from the overhead line to the power converter via the current collector by making the connection point non-conductive, and a control device for controlling the converter and the switch unit, wherein when the control device switches the power supply source to the motor from the battery to the overhead line, the converter is operated in an overhead line connection stabilization waiting state in which the output current output from the converter, which is operating in the voltage control state, to the power converter is limited, and then the converter is operated in a power supply switching processing state in which the output current of the converter decreases toward zero, and when the power supply source to the motor is switched from the overhead line to the battery, the converter, which is operating in the power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero,The converter is operated in a second overhead line disconnection preparation state where the output current output from the converter to the power converter increases toward the target value. [Effects of the Invention]

[0011] According to the present invention, adverse effects on electric-driven vehicles when switching the power supply source to the electric motor can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows examples of non-trolley mode sections and trolley mode sections where dump trucks travel. [Figure 2] Figure 2 is a block diagram showing an example of the internal configuration of a trolley-type dump truck. [Figure 3A] Figure 3A is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 3B] Figure 3B is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 4A] Figure 4A is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 4B] Figure 4B is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 5A] Figure 5A is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 5B] Figure 5B is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 6A] Figure 6A is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 6B] Figure 6B is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 7A] Figure 7A is a diagram illustrating the switching operation from battery operation to trolley operation. [Figure 7B]FIG. 7B is a diagram for explaining the switching operation from battery operation to trolley operation. [Figure 8A] FIG. 8A is a diagram for explaining the switching operation from battery operation to trolley operation. [Figure 8B] FIG. 8B is a diagram for explaining the switching operation from battery operation to trolley operation. [Figure 9A] FIG. 9A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 9B] FIG. 9B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 10A] FIG. 10A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 10B] FIG. 10B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 11A] FIG. 11A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 11B] FIG. 11B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 12A] FIG. 12A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 12B] FIG. 12B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 13A] FIG. 13A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 13B] FIG. 13B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 14A] FIG. 14A is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 14B] FIG. 14B is a diagram for explaining the switching operation from trolley operation to battery operation. [Figure 15A]Figure 15A is a diagram illustrating the switching operation from trolley operation to battery operation. [Figure 15B] Figure 15B is a diagram illustrating the switching operation from trolley operation to battery operation. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. In all drawings of the embodiments, the same or corresponding parts may be denoted by the same reference numerals. <<Embodiment>> This section describes a dump truck 1, which is an example of a trolley-charging electric drive vehicle according to an embodiment of the present invention. Figure 1 shows examples of non-trolley mode sections and trolley mode sections in which the dump truck 1 travels.

[0014] Dump truck 1 is a "trolley-powered" dump truck that does not have an engine and draws the necessary power for operation from the overhead line 6, while simultaneously charging battery 2.

[0015] The dump truck 1 is equipped with a pantograph 5 as a current collector, and internally contains a battery 2 as a power source, a DC-DC converter 3 connected to the battery 2, and an electric motor 4 driven by AC power.

[0016] Dump truck 1 can be driven (forward or backward) by switching between two modes: battery operation (non-trolley mode) and trolley operation (trolley mode).

[0017] For example, sections where the dump truck 1 travels on a flat road are considered non-trolley mode sections where it operates on battery power. In these sections, the power output by the battery 2 is supplied to the electric motor 4 to drive the wheels 12 and propel the dump truck 1 forward.

[0018] The section where dump truck 1 travels up a steep slope is designated as a trolley mode section, where it operates in trolley mode. On such slopes, the output of battery 2 alone would be insufficient to keep dump truck 1 moving slowly, so it is operated in trolley mode to receive power from the overhead wire 6. At this time, pantograph 5 makes contact with the overhead wire 6 and collects DC power from it. Pantograph 5 supplies the DC power collected from the overhead wire 6 to the motor 4 via power converter 10. In the trolley mode section, battery 2 is charged by the power supplied from the overhead wire 6.

[0019] When operating as a trolley, dump truck 1 can run without using power from battery 2, and battery 2 can be charged by power from the overhead line 6. After dump truck 1 has climbed the slope and is running on a flat road again, it switches to battery operation.

[0020] Figure 2 is a block diagram showing an example of the internal configuration of a trolley-powered dump truck 1. As shown in Figure 2, the dump truck 1 comprises a battery 2, a DC-DC converter 3, an electric motor 4, a pantograph 5, a current detector 7, a voltage detector 8, a smoothing capacitor 9, a power converter 10, a gear 11, wheels 12, a control device 13, a changeover switch 14, a voltage detector 15, a current detector 16, a connection point 18, and a mode switching command unit 19. A rectification station 17 is installed on the overhead line 6.

[0021] Battery 2 is a battery module including a battery pack composed of multiple rechargeable secondary batteries. The current detector 7 is connected between one terminal of the DC-DC converter 3 and the connection point 18. The current detector 7 outputs the DC current value detected between the DC-DC converter 3 and the connection point 18 to the DC-DC converter 3.

[0022] The voltage detector 8 is connected to both terminals of the DC-DC converter 3. When the voltage detector 8 detects a DC voltage (internal DC bus voltage), the detected DC voltage value is sent to the control device 13.

[0023] The smoothing capacitor 9 is connected in parallel to the DC-DC converter 3. The smoothing capacitor 9 charges and smooths the DC voltage supplied from the DC-DC converter 3, or the DC voltage supplied from the overhead line 6 via the changeover switch 14.

[0024] The power converter 10 is connected in parallel to the smoothing capacitor 9 and converts the smoothed DC power output from the smoothing capacitor 9 into AC power.

[0025] The electric motor 4 is driven by AC power output from the power converter 10 and drives the gear 11. The wheels 12 are driven by the electric motor 4 via the gear 12. This allows the dump truck 1 to move.

[0026] The control device 13 receives a DC current value from the current detector 7 and a DC voltage value from the voltage detector 8. The control device 13 controls the DC-DC converter 3. The control device 13 is, for example, an ECU (Electronic Control Unit). An ECU is a control unit (Electronic Control Unit) that mainly consists of a microcomputer, and is also called a controller. The microcomputer includes a CPU, ROM, RAM, and interface (I / F), etc. The CPU realizes various functions by executing instructions (programs, routines) stored in ROM.

[0027] The changeover switch 14 is connected between the pantograph 5 and the connection point 18, and switches the power source input to the power converter 10 between the overhead line 6 and the battery 2. In battery operation, the changeover switch 14 cuts off the DC power supplied from the overhead line 6, and in trolley operation, it outputs the DC power supplied from the overhead line 6 to the power converter 10 from the connection point 18. In other words, the changeover switch 14 can be set to either a conductive state or a non-conductive state between the pantograph 5 and the connection point 18. By setting the connection point 18 to conductive, the changeover switch 14 switches to either an overhead line power supply state, which supplies power from the overhead line 6 to the power converter 10 via the pantograph 5, or to both the power converter 10 and the DC-DC converter 3, or to an overhead line power non-supply state, which cuts off the power supply from the overhead line 6 to the pantograph 5 via the pantograph 5 by setting the connection point 18 to non-conductive.

[0028] The voltage detector 15 detects the DC voltage between the two pantographs 5 that are in contact with the overhead wire 6, and outputs this DC voltage value to the control device 13.

[0029] The current detector 16 is connected between the overhead wire 6, which flows through one of the two pantographs 5, and the changeover switch 14. The current detector 18 outputs the DC current value detected between the overhead wire 6 and the changeover switch 14 during trolley operation to the control device 13.

[0030] The rectification station 17 rectifies the DC power supplied to the overhead line 6. The connection point 18 is used to receive the output power of the DC-DC converter 3 and the DC power of the pantograph 5. The changeover switch 14 is connected in parallel to the DC-DC converter 3 and the smoothing capacitor 9 via the connection point 18.

[0031] The mode switching command unit 19 commands the control device 13 to switch between battery operation, in which DC power supplied from the DC-DC converter 3 is output to the power converter 10, and trolley operation, in which DC power supplied from the overhead line 6 is output to the power converter 10.

[0032] Next, we will explain the operation of each part of the dump truck 1. When operating on battery power, the changeover switch 14 is off (non-conductive). At this time, DC power is output from the battery 2 via the DC-DC converter 3. The DC power output by the DC-DC converter 3 is smoothed by the smoothing capacitor 9 and converted into AC power by the power converter 10. This AC power is output to the electric motor 4. The electric motor 4, which is connected to the power converter 10, is connected to the wheels 12 via the gear 11. When the electric motor 4 drives the gear 11, the wheels 12 rotate, causing the dump truck 1 to move forward or backward or accelerate.

[0033] During trolley operation, the changeover switch 14 is ON (conductive). At this time, the pantograph 5 is connected to the overhead wire 6, and the DC power rectified by the rectification station 17 is supplied to the power converter 10 via the connection point 18. The power converter 10 converts the DC power supplied from the overhead wire 6 into AC power. The power converter 10 then drives the motor 4. The motor 4 is connected to the wheels 12 via the gear 11, and the motor 4 rotates the wheels 12. At this time, the DC-DC converter 3 operates in charge control mode, which controls the power to charge the battery 2. In charge control mode, DC power from the overhead wire 6 is also supplied to the battery 2 by the DC-DC converter 3. The overhead wire voltage is detected by the voltage detector 15. The overhead wire current is detected by the current detector 16. <Switching operation from battery operation to trolley operation> The switching operation from battery operation to trolley operation (the switching operation when switching the power supply source to the motor 4 from battery 2 to overhead line 6) will be explained using Figures 3A to 8B. As shown in Figure 3A, the DC-DC converter 3 is in battery operation mode from time t0 to the time immediately before time t1. In battery operation mode, the DC-DC converter 3 operates in voltage control mode (also referred to as "voltage control state") in which it controls the internal DC bus voltage by the output voltage.

[0034] The control device 13 transmits a voltage command to the DC-DC converter 3 to control the internal DC bus voltage. The control device 13 sets the changeover switch 14 to the off state (non-conductive state). The DC-DC converter 3 converts the DC power from the battery 2 input to the DC-DC converter 3 into a voltage according to the voltage command and outputs it.

[0035] The DC-DC converter 3 has a power upper limit limiter and a power lower limit limiter function. The control device 13 can set the power upper limit limiter and the power lower limit limiter for the DC-DC converter 3. The output power of the DC-DC converter 3 is limited to the power upper limit limit so that the output power (output current) does not exceed the power upper limit limit. The output power of the DC-DC converter 3 is limited to the power lower limit limit so that the output power (output current) does not fall below the power lower limit limit.

[0036] During the period from time t0 to the time immediately preceding time t1, the control device 13 sets both the power upper limit limiter and the power lower limit limiter to unrestricted.

[0037] During the period from time t0 to the time immediately preceding time t1, as shown by arrows a31 and a32 in Figure 3B, the DC power input from battery 2 to DC-DC converter 3 is converted by DC-DC converter 3 to a voltage according to the voltage command, and the DC power of the converted voltage is output from DC-DC converter 3. The DC power output from DC-DC converter 3 is input to power converter 10. The DC power input to power converter 10 is converted to AC power and output to motor 4 as a drive voltage (drive power) to drive motor 4.

[0038] As shown in Figure 4A, at time t1, when a mode switching operation button (not shown) on the dump truck 1 is operated, the mode switching command unit 19 sends a command to the control device 13 to switch the dump truck 1 from battery operation to trolley operation. The control device 13 controls the DC-DC converter 3 to operate in a ready state for switching (switches it).

[0039] During the period from time t1 to the time immediately preceding time t2 (period A), the control device 13 controls the DC-DC converter 3 to operate in a switching-ready state. In the switching-ready state, the DC-DC converter 3 operates in voltage control mode and operates to increase the output voltage so that the internal DC bus voltage is equal to or greater than the overhead line voltage.

[0040] The control device 13 sets both the upper and lower power limiters to unlimited. The control device 13 sends a voltage command to the DC-DC converter 3 to gradually increase the voltage to "overhead line voltage + predetermined voltage," thereby converting the voltage of the battery 2 input to the DC-DC converter 3 to a voltage according to the voltage command value and outputting it. This prevents a large potential difference from occurring when the changeover switch 14 is later set to the ON state and the operating state of the dump truck 1 switches from battery operation to trolley operation, thereby reducing the possibility of equipment damage due to rush current flowing as a result of a large potential difference. During the period from time t1 to time t4, the dump truck 1 is controlled to maintain a constant vehicle speed by disabling accelerator operation in order to stabilize the output current.

[0041] As shown in Figure 4B, during period A, as indicated by arrows a41 and a42, the DC power input from battery 2 to DC-DC converter 3 is converted by DC-DC converter 3 to a voltage according to the voltage command and output from DC-DC converter 3. The DC power output from DC-DC converter 3 is input to power converter 10. The DC power input to power converter 10 is converted to AC power and output to motor 4 as drive power to drive motor 4.

[0042] As shown in Figure 5A, at time t2, the control device 13 sets (switches) the changeover switch 14 from the off state (non-conductive state) to the on state (conductive state).

[0043] During the period from time t2 to the time immediately preceding time t3 (period B), the control device 13 controls (switches) the DC-DC converter 3 to operate in a state of waiting for the overhead line connection to stabilize.

[0044] While the overhead line connection is awaiting stabilization, the DC-DC converter 3 operates in voltage control mode, converting the DC power from the battery 2 input to the DC-DC converter 3 into a DC voltage (overhead line voltage + predetermined voltage) according to the voltage command and outputting it. The control device 13 controls the output power of the DC-DC converter 3. Specifically, the control device 13 sets the power upper limiter to "the final power value at the time immediately preceding time t2 + predetermined power". The control device 13 sets the power lower limiter to "the final power value at the time immediately preceding time t2 - predetermined power". As a result, the output power (output current) of the DC-DC converter 3 is limited so as not to exceed the power upper limiter ("the final power value at the time immediately preceding time t2 + predetermined power"), with the power upper limit being the upper limit. The output power (output current) of the DC-DC converter 3 is limited so as not to fall below the power lower limiter ("the final power value at the time immediately preceding time t2 - predetermined power"), with the power lower limit being the lower limit.

[0045] When the changeover switch 14 switches from the off state (non-conductive state) to the on state (conductive state), the overhead line 6 and the internal busbar are connected, which may cause the output current of the DC-DC converter 3 to be affected by fluctuations in the overhead line voltage. To suppress the effects of these overhead line voltage fluctuations, the output current is limited.

[0046] As shown in Figure 5B, during period B, as indicated by arrows a51 and a52, DC power is input from battery 2 to DC-DC converter 3, converted to a voltage according to the voltage command, and output. As explained in the description of the blown-out frame SF50, the output voltage of DC-DC converter 3 controls the internal DC bus voltage. The DC power output from DC-DC converter 3 is input to power converter 10. The DC power input to power converter 10 is converted to AC power and output to motor 4 as drive power to drive motor 4.

[0047] As shown in Figure 6A, during the period C from time t3, which is a certain period (predetermined period) after time t2, to the time immediately preceding time t3a, the control device 13 controls (switches) the DC-DC converter 3 to operate in the power supply switching processing state. In the power supply switching processing state, the DC-DC converter 3 operates in voltage control mode. The internal DC bus voltage is maintained by the overhead line voltage supplied from the overhead line 6.

[0048] The control device 13 controls the output power of the DC-DC converter 3. Specifically, the control device 13 sets the power upper limiter to gradually or stepwise decrease from "the final power value at the time immediately preceding time t2 + predetermined power" to zero at a predetermined rate of change per unit time as time progresses. The control device 13 also sets the power lower limiter to gradually or stepwise decrease from "the final power value at the time immediately preceding time t2 - predetermined power" to zero at the same predetermined rate of change per unit time as above as time progresses.

[0049] As a result, as shown in Figure 6B, during period C, the output current (output power) of the DC-DC converter 3, indicated by arrow a61, is controlled to decrease toward zero. Meanwhile, as described in the explanatory text of the blown-out frame SF60, the overhead line current supplied to the power converter 10, indicated by arrow a63, gradually increases.

[0050] Therefore, the control device 13 can smoothly switch the power source for supplying power to the electric motor 4, indicated by arrow a62, from the battery 2 to the overhead line 6 (smoothly switching without sudden power fluctuations), thus minimizing the impact on the movement of the dump truck 1 when switching from battery operation to trolley operation. As shown in Figure 7A, at time t3a, when the output current of the DC-DC converter 3 reaches a threshold (for example, zero), the control device 13 sends a command to the DC-DC converter 3 to change its operating mode from voltage control mode to power control mode (also referred to as "power control state"), which operates to charge the battery 2 with power supplied by the DC-DC converter 3. The DC-DC converter 3 switches its operation from voltage control mode to power control mode. During this switch, the operation of the DC-DC converter 3 stops, as described in the explanation in the blown-out box SF71. As shown in Figure 7B, from time t3a to the time immediately before time t4, the overhead line current indicated by arrow a71 gradually increases, as described in the explanation in the blown-out box SF72.

[0051] As shown in Figure 8A, from time t4 onward, the control device 13 controls (switches) the DC-DC converter 3 to operate in trolley running mode. In trolley running mode, the DC-DC converter 3 operates in power control mode. In power control mode, DC power is input from the overhead line 6 to the DC-DC converter 3, the voltage is converted, and the DC power output from the DC-DC converter 3 is output. The DC power output from the DC-DC converter 3 is input to the battery 2 to charge the battery 2. The control device 13 sets the voltage upper limit limiter of the DC-DC converter 3 to the overvoltage threshold and sets the voltage lower limit limiter of the DC-DC converter 3 to zero. As shown in the explanations of arrows a81 to a83 and the blown-out frames SF81 and SF82 in Figure 8B, from time t4 onward, the power supplied from the overhead line 6 drives the motor 4 and charges the battery 2. <Switching operation from trolley operation to battery operation> The switching operation from trolley operation to battery operation (the switching operation when switching the power supply source to the motor 4 from the overhead line 6 to the battery 2) will be explained using Figures 9A to 15B. As shown in Figure 9A, the DC-DC converter 3 is in trolley operation mode from time t10 to the time immediately before time t11. In trolley operation mode, the DC-DC converter 3 operates in power control mode, which is a control state in which it operates to charge the battery 2 by outputting the DC power input from the overhead line 6 to the battery 2. The control device 13 sets the changeover switch 14 to the ON state (conductive state).

[0052] During the period from time t10 to the time immediately preceding time t11, the electric motor 4 is driven and the battery 2 is charged by power supplied from the overhead line 6, as shown by arrows a91 to a93 in Figure 9B and the explanatory text for the blown-out frame SF90.

[0053] As shown in Figure 10A, when a mode switching operation button (not shown) on the dump truck 1 is operated at time t11, the mode switching command unit 19 sends a command to the control device 13 to switch the dump truck 1 from trolley operation to battery operation. The control device 13 switches the DC-DC converter 3 to operate in the switching start state.

[0054] During the period from time t11 to the time immediately preceding time t12 (Period A), the DCDC converter 3 operates in a switching start state. In the switching start state, the DCDC converter 3 operates in power control mode. The control device 13 sets the voltage upper limit limiter of the DCDC converter 3 to the overvoltage threshold and sets the voltage lower limit limiter of the DCDC converter 3 to zero. As a result, in the switching start state, the DCDC converter 3 operates so that the output current (output power) of the DCDC converter 3, indicated by arrow a101, gradually becomes zero, as shown in the explanatory text for the blown-out frame SF100 in Figure 10B. During the period from time t11 to time t15a, the dump truck 1 is controlled to maintain a constant vehicle speed by disabling accelerator operation in order to stabilize the output current.

[0055] As shown in Figure 11A, when the output current (output power) of the DC-DC converter 3 becomes zero at time t12, the control device 13 sends a command to the DC-DC converter 3 to change its operating mode from power control mode to voltage control mode. The control device 13 controls (switches) the DC-DC converter 3 to operate in the first overhead line disconnection preparation state.

[0056] During the period from time t12 to the time immediately preceding time t13 (period B), the DC-DC converter 3 operates in the first overhead line disconnection preparation state. In the first overhead line disconnection preparation state, the DC-DC converter 3 operates in voltage control mode. The control device 13 sets the power upper limiter to zero and the power lower limiter to zero. In the first overhead line disconnection preparation state, the DC-DC converter 3 is in standby mode with zero output current from the DC-DC converter 3.

[0057] This reduces the impact of fluctuations in the overhead line voltage on the output current of the DC-DC converter 3 when the DC-DC converter 3 switches from power control mode to voltage control mode, thereby suppressing effects such as unnecessary discharge of the battery 2 or excessive current flowing into the battery 2.

[0058] As shown by arrows a111 and a112 in Figure 11B, during period B, the motor 4 is driven by power supplied from the overhead line 6.

[0059] As shown in Figure 12A, during the period from time t13, which is a certain period (predetermined period) after time t12, to the time immediately before time t14 (period C), the control device 13 controls the DC-DC converter 3 to operate in the second overhead line disconnection preparation state. In the second overhead line disconnection preparation state, the DC-DC converter 3 operates in voltage control mode. The control device 13 sets the power upper limit limiter from "final power value at the time immediately before time t13 + predetermined power" to gradually or stepwise increase as time progresses at a predetermined rate of change per unit time. The control device 13 sets the power lower limit limiter from "final power value at the time immediately before time t13 - predetermined power" to gradually or stepwise increase as time progresses at the same predetermined rate of change per unit time as above.

[0060] Furthermore, the control device 13 transmits a voltage command to the DC-DC converter 3 so that the output voltage becomes "overhead line voltage + predetermined voltage". The DC-DC converter 3 converts the voltage of the DC power input from the battery 2 to a voltage according to the voltage command value and outputs DC power with a voltage according to the voltage command.

[0061] As a result, as shown in Figure 12B, during period C, the output current (output power) of the DC-DC converter 3 indicated by arrow a121 is controlled to gradually increase, as described in the explanatory text for the blower frame SF120. Meanwhile, the overhead line current supplied to the power converter 10 indicated by arrow a123 gradually decreases toward zero.

[0062] As a result, the control device 13 can smoothly switch the power supply source for the electric motor 4, indicated by arrow a122, from the overhead line 6 to the battery 2 (smoothly switching without sudden power fluctuations), thereby minimizing the impact on the running of the dump truck 1 when switching from battery operation to trolley operation.

[0063] As shown in Figure 13A, at time t14, when the overhead line current reaches a threshold (for example, zero), the control device 13 switches the changeover switch 14 from the ON state (conductive state) to the OFF state (non-conductive state). The control device 13 controls (switches) the DC-DC converter 3 to operate in the state of being disconnected from the overhead line.

[0064] During the period from time t14 to the time immediately preceding time t15 (period D), the DC-DC converter 3 operates in a decoupled state. In the decoupled state, the DC-DC converter 3 operates in voltage control mode. The control device 13 sends a voltage command to the DC-DC converter 3 so that the output voltage becomes "overhead line voltage + predetermined voltage". The DC-DC converter 3 converts the voltage of the DC power input from the battery 2 to a voltage according to the voltage command value and outputs DC power with a voltage according to the voltage command.

[0065] The control device 13 controls the output power of the DC-DC converter 3. Specifically, the control device 13 sets the upper power limiter to "the final power value at the time immediately preceding time t14 + predetermined power". The control device 13 sets the lower power limiter to "the final power value at the time immediately preceding time t14 - predetermined power". As a result, the output power (output current) of the DC-DC converter 3 is limited to the upper power limiter ("the final power value at the time immediately preceding time t14 + predetermined power"), and the output current is limited to the lower power limiter ("the final power value at the time immediately preceding time t14 - predetermined power").

[0066] As shown in Figure 13B, during period D, as indicated by arrows a131 and a132, DC power is input from battery 2 to DC-DC converter 3, converted to a voltage according to the voltage command, and output from DC-DC converter 3. The DC power output from DC-DC converter 3 is input to power converter 10. The DC power input to power converter 10 is converted to AC power and output, which is input to motor 4 as driving power to drive motor 4. As indicated in the description of the blower frame SF130, the output current of DC-DC converter 3 is kept at the target value.

[0067] As shown in Figure 14A, at time t15, after a certain period (a predetermined period) has elapsed from time t14, the control device 13 controls (switches) the DCDC converter 3 to operate in battery-powered mode. During the period from time t15 to the time immediately preceding time t15a, the DCDC converter 3 operates in battery-powered mode. In battery-powered mode, the DCDC converter 3 operates in voltage control mode. The control device 13 transmits a voltage command to control the internal DC bus voltage. The DCDC converter 3 converts the DC power input from the battery 2 into a voltage according to the voltage command and outputs DC power of the converted voltage.

[0068] The control device 13 controls the output power of the DC-DC converter 3. The control device 13 sets the power upper limiter from "the final power value at the time immediately preceding time t15 + predetermined power" to gradually or stepwise increase as time progresses at a predetermined rate of change per unit time. The control device 13 also sets the power lower limiter from "the final power value at the time immediately preceding time t15 - predetermined power" to gradually or stepwise decrease as time progresses at a predetermined rate of change per unit time. As a result, the limit on the output power output from the DC-DC converter 3 is gradually released. As shown in Figure 14B, the motor 4 is driven by power supplied from the battery 2 during the period from time t15 to the time immediately preceding time t15a.

[0069] As shown in Figure 15A, from time t15a onward, the control device 13 controls the DC-DC converter 3 to continue operating in battery-powered mode. From time t15a onward, the DC-DC converter 3 operates in battery-powered mode. In battery-powered mode, it operates in voltage control mode.

[0070] The control device 13 transmits a voltage command to control the internal DC bus voltage. The DC-DC converter 3 converts the DC power input from the battery 2 into a voltage according to the voltage command and outputs DC power of the converted voltage. The control device 13 sets both the power upper limiter and the power lower limiter to unrestricted. As shown in Figure 15B, the motor 4 is driven by the power supplied from the battery 2 during the period from time t15 to the time immediately preceding time t15a. <Effects> As described above, the dump truck 1 according to the embodiment of the present invention can switch the power supply source to the electric motor while suppressing adverse effects on the dump truck 1. <<Variation>> The present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention. For example, the present invention can also take the following configuration. [1] A control device for an electric drive vehicle, which is a trolley-charging type electric drive vehicle that is equipped with an electric motor, a battery and a current collector, runs on the electric motor which is driven by power supplied from the battery and / or an overhead line, and is capable of charging the battery with power supplied from the overhead line, The aforementioned electric vehicle is A power converter that converts the input DC power into AC power and outputs it to the motor, A converter connected to the aforementioned power converter, capable of operating in either a voltage-controlled state in which it receives DC power from the battery, converts the voltage, and outputs the converted DC power to the power converter, or a power-controlled state in which it receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery, A current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter, The current collector and the connection point can be set to either a conductive state or a non-conductive state, and a switch unit for switching between either a power supply state, in which power is supplied from the overhead line to the power converter, or to both the power converter and the converter, by setting the connection point to a conductive state, and a non-conductive state, in which power is cut off from the power supply from the overhead line to the power converter via the current collector by setting the connection point to a non-conductive state. Equipped with, The control device is configured to control the converter and the switch unit, The control device is When switching the power supply source to the electric motor from the battery to the overhead line, After operating the converter in a state of waiting for the overhead line connection to stabilize, which limits the output current output from the converter to the power converter while it is operating in the voltage control state, the converter is then operated in a power supply switching state in which the output current of the converter decreases toward zero. When switching the power supply source to the electric motor from the overhead line to the battery, The converter, which is operating in the aforementioned power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero, and then the converter is operated in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value. It is configured in such a way. Control device for electric vehicles. [2] A control method for an electric drive vehicle applicable to a trolley-charging electric drive vehicle equipped with an electric motor, a battery and a current collector, which runs using the electric motor driven by power supplied from the battery and / or an overhead line as a power source, and which is capable of charging the battery with power supplied from the overhead line, The aforementioned electric vehicle is A power converter that converts the input DC power into AC power and outputs it to the motor, A converter connected to the aforementioned power converter, capable of operating in either a voltage-controlled state in which it receives DC power from the battery, converts the voltage, and outputs the converted DC power to the power converter, or a power-controlled state in which it receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery, A current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter, The current collector and the connection point can be set to either a conductive state or a non-conductive state, and a switch unit for switching between either a power supply state, in which power is supplied from the overhead line to the power converter, or to both the power converter and the converter, by setting the connection point to a conductive state, and a non-conductive state, in which power is cut off from the power supply from the overhead line to the power converter via the current collector by setting the connection point to a non-conductive state. A control device that controls the converter and the switch unit, Equipped with, The aforementioned control device, When switching the power supply source to the electric motor from the battery to the overhead line, After operating the converter in a state of waiting for the overhead line connection to stabilize, which limits the output current output from the converter to the power converter while it is operating in the voltage control state, the converter is then operated in a power supply switching state in which the output current of the converter decreases toward zero. When switching the power supply source to the electric motor from the overhead line to the battery, The converter, which is operating in the aforementioned power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero, and then the converter is operated in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value. A control method for electric vehicles. [Explanation of Symbols]

[0071] 1...Dump truck, 2...Battery, 3...DC-DC converter, 4...Electric motor, 5...Pantograph, 6...Overhead line, 10...Power converter, 13...Control device, 14...Changeover switch

Claims

1. A trolley-charging electric vehicle equipped with an electric motor, a battery and a current collector, which runs using the electric motor, driven by power supplied from the battery and / or overhead lines, as its power source, and which is capable of charging the battery with power supplied from the overhead lines, A power converter that converts the input DC power into AC power and outputs it to the motor, A converter connected to the aforementioned power converter, capable of operating in either a voltage-controlled state in which it receives DC power from the battery, converts the voltage, and outputs the converted DC power to the power converter, or a power-controlled state in which it receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery, A current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter, The current collector and the connection point can be set to either a conductive state or a non-conductive state, and a switch unit for switching between either a power supply state, in which power is supplied from the overhead line to the power converter, or to both the power converter and the converter, by setting the connection point to a conductive state, and a non-conductive state, in which power is cut off from the power supply from the overhead line to the power converter via the current collector by setting the connection point to a non-conductive state. A control device that controls the converter and the switch unit, Equipped with, The control device is When switching the power supply source to the electric motor from the battery to the overhead line, After operating the converter in a state of waiting for the overhead line connection to stabilize, which limits the output current output from the converter to the power converter while it is operating in the voltage control state, the converter is then operated in a power supply switching state in which the output current of the converter decreases toward zero. When switching the power supply source to the electric motor from the overhead line to the battery, The converter, which is operating in the aforementioned power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero, and then the converter is operated in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value. It is configured in such a way. Electrically driven vehicle.

2. In the electric drive vehicle according to claim 1, The control device is When switching the power supply source from the battery to the overhead line, the switch unit operates the converter in a switching preparation state, before the timing of making the overhead line and the connection point conductive, such that the output power of the converter is increased to be equal to or greater than the overhead line voltage. It is configured in such a way. Electrically driven vehicle.

3. In the electric drive vehicle according to claim 2, The control device, via the switch unit, switches the converter to operate in the overhead line connection stabilization waiting state at the timing when the overhead line and the connection point are made conductive. It is configured in such a way. Electrically driven vehicle.

4. In the electric drive vehicle described in claim 3, The control device operates the converter for a predetermined period of time while waiting for the overhead line connection to stabilize, and then operates the converter while in the power supply switching processing state. It is configured in such a way. Electrically driven vehicle.

5. In the electric drive vehicle according to claim 1, When the control device switches the power supply source from the overhead line to the battery, Before the first overhead line disconnection preparation state, the converter is operated in a switching start state in which the output current to the battery is reduced to zero. It is configured in such a way. Electrically driven vehicle.

6. In the electric drive vehicle according to claim 5, The control device switches to operating the converter in the first overhead line disconnection preparation state at the timing when the output current to the battery becomes zero. It is configured in such a way. Electrically driven vehicle.

7. In the electric drive vehicle according to claim 6, The control device operates the converter for a predetermined period of time in the first overhead line disconnection preparation state, then operates the converter in the second overhead line disconnection preparation state, and when the overhead line current supplied from the overhead line to the power converter reaches a predetermined threshold, the switch unit causes the connection between the current collector and the connection point to become non-conductive. It is configured in such a way. Electrically driven vehicle.

8. A control device for an electric drive vehicle, which is a trolley-charging type electric drive vehicle that is equipped with an electric motor, a battery and a current collector, runs on the electric motor which is driven by power supplied from the battery and / or an overhead line, and is capable of charging the battery with power supplied from the overhead line, The aforementioned electric vehicle is A power converter that converts the input DC power into AC power and outputs it to the motor, A converter connected to the aforementioned power converter, capable of operating in either a voltage-controlled state in which it receives DC power from the battery, converts the voltage, and outputs the converted DC power to the power converter, or a power-controlled state in which it receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery, A current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter, The current collector and the connection point can be set to either a conductive state or a non-conductive state, and a switch unit for switching between either a power supply state, in which power is supplied from the overhead line to the power converter, or to both the power converter and the converter, by setting the connection point to a conductive state, and a non-conductive state, in which power is cut off from the power supply from the overhead line to the power converter via the current collector by setting the connection point to a non-conductive state. Equipped with, The control device is configured to control the converter and the switch unit, The control device is When switching the power supply source to the electric motor from the battery to the overhead line, After operating the converter in a state of waiting for the overhead line connection to stabilize, which limits the output current output from the converter to the power converter while it is operating in the voltage control state, the converter is then operated in a power supply switching state in which the output current of the converter decreases toward zero. When switching the power supply source to the electric motor from the overhead line to the battery, The converter, which is operating in the aforementioned power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero, and then the converter is operated in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value. It is configured in such a way. Control device for electric vehicles.

9. A control method for an electric drive vehicle applicable to a trolley-charging electric drive vehicle equipped with an electric motor, a battery and a current collector, which runs using the electric motor driven by power supplied from the battery and / or an overhead line as a power source, and which is capable of charging the battery with power supplied from the overhead line, The aforementioned electric vehicle is A power converter that converts the input DC power into AC power and outputs it to the motor, A converter connected to the aforementioned power converter, capable of operating in either a voltage-controlled state in which it receives DC power from the battery, converts the voltage, and outputs the converted DC power to the power converter, or a power-controlled state in which it receives DC power from the overhead line, converts the voltage, and outputs the converted DC power to the battery, A current collector whose power input side is connected to the overhead line and whose power output side is connected at the connection point between the converter and the power converter, The current collector and the connection point can be set to either a conductive state or a non-conductive state, and a switch unit for switching between either a power supply state, in which power is supplied from the overhead line to the power converter, or to both the power converter and the converter, by setting the connection point to a conductive state, and a non-conductive state, in which power is cut off from the power supply from the overhead line to the power converter via the current collector by setting the connection point to a non-conductive state. A control device that controls the converter and the switch unit, Equipped with, The aforementioned control device, When switching the power supply source to the electric motor from the battery to the overhead line, After operating the converter in a state of waiting for the overhead line connection to stabilize, which limits the output current output from the converter to the power converter while it is operating in the voltage control state, the converter is then operated in a power supply switching state in which the output current of the converter decreases toward zero. When switching the power supply source to the electric motor from the overhead line to the battery, The converter, which is operating in the aforementioned power control state, is switched from the power control state to the voltage control state, and the converter is operated in a first overhead line disconnection preparation state in which the output current output to the power converter is limited to zero, and then the converter is operated in a second overhead line disconnection preparation state in which the output current output from the converter to the power converter increases toward a target value. A control method for electric vehicles.

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