Electric vehicle

Abstract

An electric vehicle (1) is provided with: a current collector (2); one or more charging devices (3) that are charged by an auxiliary power supply device connected to the current collector (2); a travel inverter (5) for driving the main motor (9); and a switch (61) that switches the connection between the charging device (3) and the travel inverter (5) from disconnection to connection when the current collector (2) is disconnected from the power supply.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Japanese Patent Application No. 2023-007681 filed on January 20, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to an electric vehicle capable of traveling with power supply cut off. Background Art

[0003] Electric railway vehicles generally travel by receiving power from overhead wires or third rails. In addition, when the overhead wires or substations that are the power supply sources fail, they are usually unable to travel. In particular, when a vehicle stops at a dangerous place such as a bridge during a large-scale disaster where passengers cannot get off, it is necessary to use some method to move the vehicle slightly, let the passengers get off and evacuate to a safer place.

[0004] Therefore, a storage battery connected to the main circuit system and its charging and discharging system are usually mounted on the vehicle. Patent Document 1 solves the above-mentioned problem by providing a large power storage device in the DC unit.

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent No. 5161816 Summary of the invention

[0006] Technical issues However, for the purpose of emergency running, the general method of using a large-capacity storage battery and applying the rated voltage to the system in an emergency situation results in a system that is too large, and the cost of installing it in the entire train becomes a problem.

[0007] The present invention has been made in view of the above circumstances and has an object to provide an electric vehicle capable of performing mode switching in an emergency without mounting a large-scale power storage system.

[0008] Technical Solution An electric vehicle system in one embodiment comprises: a power collection device; one or more charging devices that are charged by an auxiliary power supply device connected to the power collection device; a driving inverter that drives a main motor; and a switch that switches the connection between the charging device and the driving inverter from disconnection to connection when the power collection device is disconnected from the power supply.

[0009] Furthermore, in one embodiment, a total voltage of the one or more charging devices may be greater than or equal to 10% and less than or equal to 20% of the voltage of the power source.

[0010] Furthermore, in one embodiment, a current collection detection device may be provided, the current collection detection device mechanically detecting a connection state between the current collection device and the overhead wire and outputting a signal indicating a detection result.

[0011] Furthermore, in one embodiment, the switch can also switch the connection between the charging device and the driving converter from disconnection to connection when the current collection detection device outputs a signal indicating that the current collection device has been disconnected from the overhead line, the capacitors of the auxiliary power supply device and the driving converter have been discharged, and no current is flowing through the auxiliary power supply device and the driving converter.

[0012] Technical Effects According to the present invention, it is possible to perform mode switching in an emergency without installing a large-scale power storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a configuration diagram showing an example of an electric vehicle according to an embodiment of the present invention.

[0014] Figure 2 This is a simplified circuit diagram of an electric vehicle according to one embodiment of the present invention.

[0015] Explanation of symbols 1: electric vehicle, 2: power collection device, 3: charging device, 4: auxiliary power supply device, 5: driving inverter, 6: switching switch box, 9: main motor, 10: power collection detection device, 11: air conditioning device, 12: high-voltage power supply line, 13: control power line in the vehicle, 20: overhead line, 61: switch. DETAILED DESCRIPTION

[0016] Hereinafter, one embodiment will be described in detail with reference to the drawings.

[0017] Figure 1 It is a structural diagram showing an example of an electric vehicle according to one embodiment. Figure 1 The electric vehicle 1 shown includes: a power collection device 2, one or more charging devices (second power supply, Batt) 3, an auxiliary power supply device (APU) 4, a driving inverter (PropINV) 5, a switching switch box (SW) 6, a main motor 9, a power collection detection device 10, an air conditioning device (HVAC) 11, a high-voltage power supply line 12 and an in-vehicle control power supply line 13.

[0018] The power collector 2 supplies the electric power collected from the overhead wire (first power source) 20 to the driving inverter 5, the auxiliary power source device 4, and the switch box 6 via the high-voltage power supply line 12. Figure 1In the present embodiment shown, an overhead tram line method (overhead line power collection method) is shown in which a pantograph is used as the power collection device 2 to collect power from the overhead line 20, but the present invention can also be applied to a third rail method in which a collector shoe is used as the power collection device 2 to collect power from a third rail (first power source).

[0019] The driving inverter 5 supplies power to a main motor 9 for driving the vehicle (for driving), and drives the main motor 9. In the present embodiment, three-phase AC power is temporarily supplied to the main motor 9, but the main motor 9 may be a DC motor.

[0020] The auxiliary power supply device 4 is a power conversion device connected to the power collection device 2. The auxiliary power supply device 4 supplies power to the charging device 3 (second power supply), the control power supply of the driving inverter 5, the control power supply of the auxiliary power supply device 4, the air conditioner 11, and the switch box 6 via the in-vehicle control power supply line 13.

[0021] The charging device 3 is a small-capacity control battery, which is charged by the auxiliary power supply device 4 .

[0022] In order to detect whether the current collector 2 is receiving power supply, the current collection detection device 10 mechanically detects the connection state between the current collector 2 and the overhead wire 20, and outputs a signal indicating the detection result. For example, when the current collector 2 is a pantograph, the current collector 2 is usually folded and not connected to the overhead wire 20 when the vehicle power is turned on, and the current collection detection device 10 outputs a contact signal of "not raised".

[0023] The switch box 6 has a switch 61 for switching current, such as a mechanical switch or a semiconductor switch. The switch 61 switches the connection between any charging device 3 and the driving inverter 5 from disconnection to connection when the collector 2 is disconnected from the overhead line 20 and the current consumption of the collector 2 is below a threshold.

[0024] The voltage of the charging device 3 is generally rated at 100 to 110V DC, or rated at 24V, 36V or 48V DC. The voltage of the overhead wire 20 is generally 600V, 750V, 1500V or 3000V DC. In the case of 24V, 36V or 48V DC, the voltage is lower than the original rated voltage, and the torque required to drive the electric vehicle 1 cannot be output from the main motor 9. In order to drive the electric vehicle 1, it is considered that the total voltage of the charging devices 3 needs to be 10% or more relative to the voltage of the overhead wire 20. Therefore, when the voltage of each charging device 3 when fully charged is less than 10% of the voltage of the overhead wire 20, it is necessary to set a plurality of charging devices 3. However, in order to achieve the purpose of moving the vehicle slightly to a safe place in an emergency, it is considered that a voltage exceeding 20% ​​relative to the voltage of the overhead wire 20 is not necessary. Therefore, the total voltage of the charging devices 3 is preferably 10% or more and 20% or less relative to the voltage of the overhead wire 20.

[0025] <Normal mode and emergency driving mode> Next, refer to Figure 2 Switching between the normal mode and the emergency travel mode will be described. Figure 2 It is a simplified circuit diagram of the electric vehicle 1 .

[0026] In the normal mode, the main motor 9 is driven by the power supplied from the power collector 2. In addition, the auxiliary power supply device 4 is operated by the power supplied from the power collector 2. The auxiliary power supply device 4 supplies power to auxiliary devices such as the air conditioner 11, interior lights, and a compressor. In addition, the auxiliary power supply device 4 charges the charging device 3 via the in-vehicle control power supply line 13, and supplies power to the control power supply of the driving inverter 5.

[0027] When the power supply from the overhead wire 20 is disconnected, the normal mode is switched to the emergency travel mode. At this time, the power collector 2 must be reliably separated from the overhead wire 20 before the potentials of the in-vehicle control power supply line 13 and the high-voltage power supply line 12 become the same.

[0028] Therefore, first, a mode switching command is set from within the vehicle. Then, the electric vehicle 1 simultaneously executes the following operations (1), (2), and (3).

[0029] (1) The current collector 2 is lowered and separated from the overhead wire 20. When the current collector 2 is lowered, the current collection detection device 10 outputs a signal indicating that the current collector 2 is separated from the overhead wire 20 (a signal indicating that the current collector 2 is not raised).

[0030] (2) Auxiliary power supply device 4 and driving inverter 5 The contactors inside the auxiliary power supply device 4 and the driving inverter 5 are opened to discharge the charges stored in the capacitors inside the auxiliary power supply device 4 and the driving inverter 5. This operation can eliminate the influence of the charges stored in the capacitors.

[0031] (3) The control circuit detects that the current values ​​of the driving inverter 5 and the auxiliary power supply device 4 are zero.

[0032] After confirming the above three conditions, i.e., confirming that (1) the current collection detection device 10 outputs a signal indicating that the current collection device 2 has been disconnected from the overhead line 20, (2) the capacitors of the auxiliary power supply device 4 and the driving inverter 5 have been discharged, and (3) there is no current flowing in the auxiliary power supply device 4 and the driving inverter 5, the control circuit of the electric vehicle 1 switches both sets of switches 61 in the switch box 6 from off to on. In this way, the normal mode is switched to the emergency driving mode.

[0033] At this time, the power collector 2 is disconnected from the overhead line 20. Therefore, the potential of the in-vehicle control power line 13 becomes equal to the potential of the high-voltage power supply line 12, and power can be supplied from the charging device 3 to the driving inverter 5.

[0034] In the emergency driving mode, the driving inverter 5 starts to operate and starts to supply power to the main motor 9. Thus, the electric vehicle 1 of the present invention can switch to driving based on the charging device 3 as the second power source even in an emergency situation where the power supply from the first power source that normally consumes power is disconnected. In addition, the system of the electric vehicle 1 can be constructed by increasing the number of small, small-capacity low-voltage batteries installed in existing equipment, and since a large, large-capacity battery is not required if the vehicle is only moved, it can be realized in a low-cost and small manner.

[0035] The above-mentioned embodiments are described as representative examples, but it is obvious to those skilled in the art that various changes and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited by the above-mentioned embodiments, but can be variously deformed or changed within the scope of the claims. For example, multiple building blocks recorded in the structural diagram of the embodiment can be merged, or one building block can be split.

Claims

1. An electric vehicle, characterized in that: have: Current collecting device; one or more charging devices, which are charged by an auxiliary power supply device connected to the power collection device; A driving inverter that drives the main electric motor; as well as A switch switches the connection between the charging device and the driving inverter from disconnection to connection when the power collection device is disconnected from the power supply.

2. The electric vehicle according to claim 1, characterized in that A total voltage of the one or more charging devices is greater than or equal to 10% and less than or equal to 20% of a voltage of the power source.

3. The electric vehicle according to claim 1 or 2, characterized in that: The electric vehicle includes a current collection detection device that mechanically detects a connection state between the current collection device and the overhead wire and outputs a signal indicating a detection result.

4. The electric vehicle according to claim 3, characterized in that: The switch switches the connection between the charging device and the driving inverter from disconnection to connection when the current collection detection device outputs a signal indicating that the current collection device has been disconnected from the overhead line, the capacitors of the auxiliary power supply device and the driving inverter have been discharged, and no current is flowing through the auxiliary power supply device and the driving inverter.

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