JP3099313B2 - Electric car power protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply protection device for an electric vehicle which performs a power supply protection operation by detecting an overcurrent flowing through a load.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional power supply protection device for an electric vehicle that detects an overcurrent flowing in a load and performs a power supply protection operation.
Is known. This conventional electric vehicle power supply protection device includes power supply devices 4 and 5 for receiving power to the overhead line 1 through a plurality of current collectors 2 and 3, respectively, and detects an overcurrent in each of the power supply devices 4 and 5. Noncontact high-speed overcurrent protection circuits 6 and 7 for shutting off power at high speed are mounted. Further, breakers 10 and 11 for performing a mechanical shutoff operation such as no-fuse breakers are provided on power supply lines 14 and 15 from the power supply devices 4 and 5 to the loads 8 and 9 respectively. A power supply / reception line 13 having a power supply / reception contactor 12 is connected between the power supply 14 and the power supply 15.

[0003] In such a conventional power supply protection device for an electric vehicle, as shown in the flowchart of FIG.
For example, when a ground fault occurs in the load 8 and an overcurrent flows through the power supply line 14 (step S1), the overcurrent protection circuit 6 in the power supply device 4 that operates at a high speed first activates the overcurrent (O).
C) to detect and shut off the power (steps S2, S
3). Thereafter, the overcurrent protection circuit 6 automatically recovers (step S4). However, since the ground fault on the load 8 side has not been resolved, an overcurrent flows again, so that the overcurrent protection circuit 6 restarts. Detects and performs power shutdown operation (step S
5) The power supply device 4 is locked out by the second protection operation as a preset limited number of times (step S6).

Even if one of the power supply devices 4 is locked out, the other power supply device 5 is alive, so that power is again supplied from the power supply device 5 to the load 8 through the power receiving contactor 12 and the power receiving line 13. (Steps S7 and S8), but since the ground fault on the load 8 side has not been eliminated, the overcurrent protection circuit 7 on the power supply 5
Lockout by performing the protection operation (steps S9 to S9).
S13), the whole system is down (step S14).

When the overcurrent protection operation is performed, the power supply line 1
The circuit breaker 10 performing the mechanical shut-off operation on the circuit 4 has a response to overcurrent of the order of several milliseconds, and the response of the contactless high-speed overcurrent protection circuit 6 is on the order of microseconds. As a result, the overcurrent protection circuit 6 responds to the overcurrent and shuts off the power supply, so that the breaker 10 does not perform the protection operation against the overcurrent and the system goes down. .

[0006]

However, in such a conventional power supply protection device for an electric vehicle, when a ground fault accident occurs in a load, the location where the accident occurs is not particularly important. If it can be disconnected from the system, it is often safe to supply power to other loads without shutting down the system, but the system will always go down regardless of the ground fault at any load As a result, there is a problem that it is necessary to immediately stop the running of the electric car and perform a garage inspection.

The present invention has been made in view of such a conventional problem. Even if a ground fault occurs in an unimportant load, the breaker is forcibly shut off with respect to the load, and an important load is prevented. An object of the present invention is to provide a power supply protection device for an electric vehicle that can continue to supply power to a normal vehicle.

[0008]

According to a first aspect of the present invention, a power supply unit that receives power from an overhead line through a current collector is equipped with a contactless high-speed overcurrent protection circuit having an automatic recovery function, and power is supplied from the power supply unit to a load. In a power supply protection device for an electric vehicle provided with a breaker having a mechanical contact on a power supply line, two breakers having a mechanical contact are connected in parallel to a power supply line from the power supply device, and a load is applied to an output side of each breaker. The power supply device includes a forced trip circuit for giving a forced trip command to a specific one of the two breakers by a limited number of overcurrent protection operations of the high-speed overcurrent protection circuit.

According to a second aspect of the present invention, each of a plurality of power supply devices receiving power from an overhead line through a current collector is provided with a high-speed overcurrent protection circuit having an automatic recovery function. A power supply protection device for an electric vehicle, comprising a breaker having a power contact and interconnecting power supply lines of a plurality of power supply devices by a power supply / reception line having a power supply / reception contactor. The two breakers having the electrical contacts are connected in parallel, the load is connected to the output side of each breaker, and each of the plurality of power supply units is provided with a limited number of times of the high-speed overcurrent protection circuit mounted on the power supply unit. A forced trip circuit for giving a forced trip command to a specific one of the two breakers by a current protection operation, and a forced trip circuit after the forced trip of the specific breaker by the forced trip circuit. Is provided with a receiving electric stop circuit to prohibit the receiving electric operation of the receiving electric contactor detects the overcurrent protection operation of fast overcurrent protection circuit.

[0010]

In the power supply protection device for an electric vehicle according to the first aspect of the present invention,
An important load and a normal load are separately connected to the output side of each of the two breakers connected in parallel to the power supply line from the power supply device. The breaker on the side to which the normal load is connected is a specific breaker. If the overcurrent protection circuit performs a limited number of overcurrent protection operations, a forced trip circuit provided in the power supply unit forcibly applies the specific breaker. A trip command is given to forcibly trip a specific breaker. If a specific breaker trips in this way, then
Normally, when the overcurrent protection circuit automatically recovers, the load side is disconnected from the power supply device and power is not supplied.

Therefore, if the cause of the overcurrent is on the normal load side, the normal load side is disconnected from the power supply device. Therefore, after the overcurrent protection circuit automatically recovers again, the important load side returns to the normal load side as usual. The power supply is restarted, and the lockout of the power supply device does not occur. On the other hand, if a ground fault has occurred on the important load side, an overcurrent will flow again after the overcurrent protection circuit automatically recovers again and the power supply will be cut off, and the power supply will be locked out. In the event that a ground fault occurs in a critical load, the vehicle should be immediately put in the garage and repaired, so that it can be reliably detected and protected, and the reliability of the overcurrent protection operation must be maintained. Can be done.

In the power supply protection device for an electric vehicle according to the second aspect of the present invention, an important load and a normal load are separately connected to the output side of each of two breakers connected in parallel to a power supply line from each power supply device. The breaker on the side to which the normal load is connected is a specific breaker. If the overcurrent protection circuit performs a limited number of overcurrent protection operations, a forced trip circuit provided in the power supply unit forcibly applies the specific breaker. A trip command is given to forcibly trip a specific breaker. If the specific breaker trips in this way, then, when the overcurrent protection circuit automatically recovers, the normal load side is disconnected from the power supply device and power is not supplied.

Therefore, if the cause of the overcurrent is on the normal load side, the normal load side is disconnected from the power supply device. Therefore, after the overcurrent protection circuit automatically recovers again, the important load side returns to the normal load side as usual. The power supply is restarted, and the lockout of the power supply device does not occur.

On the other hand, if a ground fault has occurred on the important load side, after the overcurrent protection circuit automatically recovers again, an overcurrent flows again and the power is cut off, and the power supply is locked out. become. After that, if the overcurrent protection operation is performed immediately after the automatic recovery from the overcurrent protection circuit, a ground fault has occurred on the important load side. If the power is supplied to the important load through the electric wire, the other power supply devices are also locked out, resulting in a system down.

Therefore, if an overcurrent protection operation occurs even after a breaker to which a normal load is connected in one power supply device is forcibly tripped, a ground fault occurs in the important load connected to this power supply device. The power supply / reception function is stopped assuming that a power failure has occurred, preventing the other power supply from affecting the system and causing the system to go down, and continuing its operation only on the power supply connected to a normal load. To minimize the effects of ground faults and improve the reliability of the system.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit diagram of a common embodiment of the first and second aspects of the present invention. In the power supply protection device for an electric vehicle according to this embodiment, a plurality of contactless high-speed overcurrent protection circuits 6 and 7 having an automatic return function are provided in a plurality of power supply devices 4 and 5 that receive power from the overhead line 1 through the current collectors 2 and 3 respectively. No-fuse breakers (NFB) 10A, 1 which are mounted and have mechanical contacts on power supply lines 14, 15 from power supply devices 4, 5, respectively.
0B, No fuse breaker (NFB) 11A, 11B
Are connected in parallel, and one of the breakers 10A and 11A on each of the feed lines 14 and 15 has a normal load 8A, 9 such as a cooler, ventilation, room light, etc., which are not so important.
A each is connected and the other breaker 10 on each feeder line
Important loads 8B and 9B, such as train radio, on-board control, and security devices, are connected to B and 11B, respectively.

The power supply lines 14 and 15 of the plurality of power supply devices 4 and 5
A power receiving / feeding line 13 is connected between the power receiving and feeding lines 13, and a power receiving / feeding contactor 12 is provided on the power receiving / feeding line 13.

A plurality of contactless high-speed overcurrent protection circuits 6 mounted on each of the plurality of power supply devices 4 and 5 are provided.
7. Each of the two breakers 10A, 10B; 11 by a limited number of times, in this embodiment, two times of overcurrent protection operation.
The forced trip circuits 16 and 17 for giving a forced trip command to the specific breakers 10A and 11A on the side to which the normal loads 8A and 9A are connected, respectively, and the forced trip circuits 16 and 17 respectively. The contactless high-speed overcurrent protection circuits 6 and 7 after the forcible trip of the breakers 10A and 11A respectively detect the overcurrent protection operation (the third protection operation in this embodiment) to detect the overcurrent protection operation.
Power supply / reception stop circuits 18, 19 for stopping the power supply / reception operation 2
Each is provided.

Next, the operation of the power supply protection device for an electric vehicle having the above configuration will be described. In the normal state, the power supply contactor 12
Is open, and each of the power supply devices 4 and 5 operates independently to load two loads 8A,
8B; power is equally supplied to 9A and 9B.

When one of the power supply devices 4 and 5 is stopped, the power receiving / contacting device 12 is turned on in response to an external command, and the load connected to the stopped power supply device is in operation. The power is continuously supplied from the power supply device. For example, if the power supply 4 is stopped now,
Power is supplied to the loads 8A and 8B connected to the power supply unit 4 from the power supply unit 5 through the power supply and receiving lines 13A and 13B.

Next, a case where a ground fault has occurred in the normal load 8A of the power supply device 4 and an overcurrent has started to flow will be described with reference to the flowchart of FIG. When a ground fault occurs in the normal load 8A and an overcurrent flows through the power supply device 4 (step S21), the overcurrent protection circuit 6 performs a protection operation by detecting an overcurrent, and stops power supply (step S2).
2, S23).

Thereafter, when the overcurrent protection circuit 6 automatically recovers and the power supply device 4 is restarted, the specific breaker 10A for the normal load 8A has not tripped, so that the current starts to flow again to the normal load 8A. The overcurrent protection circuit 6 performs the second overcurrent protection operation set as the limited number of times (step S25), the power supply device 4 is stopped, and the forced trip circuit 16 causes the specific breaker (NFB) on the normal load 8A side. 10A is forcibly tripped,
The normal load 8A in which the ground fault has occurred is disconnected (steps S26 and S27).

Thereafter, the overcurrent protection circuit 6 automatically recovers again (step S28). However, since the normal load 8A in which the ground fault has occurred is disconnected from the power supply line 14, power is supplied to the normal load 8A. Therefore, the overcurrent stops flowing, and the power supply from the power supply device 4 to the important load 8B is resumed as usual (step S29).

In this way, by connecting the normal load 8A to the specific breaker 10A side tripped by the forced trip circuit 16 and connecting the important load 8B to the other breaker 10B side, a ground fault occurs in the normal load 8A. Does not lock out the power supply device 4 even if the power failure occurs, the power can be continuously supplied to the subsequent important load 8B.

Next, the operation when a ground fault has occurred in the important load 8B will be described. In this case, the restart of the power supply unit 4 is stopped, and the power receiving / supplying function is also stopped, and the important load 8B is stopped. It is necessary to perform a protection operation so that overcurrent is continuously supplied to prevent burnout and other serious accidents, and at the same time, on the power supply unit 5 side where no ground fault accident occurs, the load 9A directly connected to the power supply unit 5 is connected. , 9B.

In this embodiment, the protection operation is performed as follows. That is, as shown in the flowchart of FIG. 3, when a ground fault occurs in the important load 8B of the power supply device 4 and an overcurrent flows (step S31), the overcurrent protection circuit 6 detects the overcurrent and protects the overcurrent. It operates and stops the power supply device 4 (steps S32 and S33).

Thereafter, the overcurrent protection circuit 6 automatically recovers,
The power supply device 4 is restarted (step S34), and power is again supplied to the important load 8B, so that an overcurrent starts to flow,
The overcurrent protection circuit 6 performs the second protection operation set as the limited number of times (step S35), and the power supply device 4
Is stopped, and the specific breaker 10A on the normal load 8A side is forcibly tripped by the forcible trip circuit 16 (steps S36 and S37).

However, since this forced trip is for the breaker 10A connected to the normal load 8A where no ground fault has occurred, the overcurrent protection circuit 6 automatically returns again after this, and the power supply becomes important. When power is supplied to the load 8B, an overcurrent flows again and the overcurrent protection circuit 6 performs an overcurrent protection operation, and the power supply device 4 locks out (step S40). Along with this lockout, the power supply / reception stop circuit 18 also operates to output a power supply / reception stop command to the power supply / reception contactor 12, and power is supplied from the other power supply device 5 to the important load 8B side via the power supply / reception line 13. Is prohibited (step S41). After this protection operation, only the power supply device 5 to which the normal loads 9A and 9B are connected continues normal operation (step S42).

In this way, when a ground fault occurs in the important load 8B connected to one power supply 4 and an overcurrent flows, the power supply is not operated unless the important load 8B operates. It is not meaningful for the electric vehicle as a whole even if the power supply 4 continues to supply power only to the normal load 8A. In such a case, the power supply 4 is securely locked out and the other power supply 5 is also prohibited, and the important load 8B is protected from any further serious accident.

Although the protection operation at the time of detecting an overcurrent on the side of the power supply device 4 has been described above, the same operation is performed when the overcurrent is detected on the side of the power supply device 5. This is executed by the stop circuit 19.

When the power supply device 4 or the power supply device 5 is stopped for a reason other than the protection operation at the time of detecting an overcurrent, the normal load is supplied from the power supply device 5 or the power supply device 4 on the normal side through the power receiving contactor and the power receiving line 13. And the power supply to the important load is continued.

Further, in the above-mentioned embodiment, the overcurrent protection circuit, the forced trip circuit and the power supply / reception stop circuit can be constituted as electronic circuits using semiconductors. It is also possible to realize by software, and the realization method is not particularly limited.

In the first aspect of the present invention, the present invention is not particularly limited to the above-described circuit configuration.
Each power supply unit operates independently to protect against overcurrent.In the event of a ground fault at a normal load, only the specific breaker is forcibly tripped and disconnected, and power can be continuously supplied to the normal critical load side. A simple configuration that locks out the power supply unit when an overcurrent cannot be resolved even after a preset number of restarts, for example, a third restart, when a ground fault occurs in a critical load Can also.

[0034]

As described above, according to the first aspect of the present invention,
An important load and a normal load are separately connected to the output side of each of the two breakers connected in parallel to the power supply line from the power supply device, and the breaker on the side to which the normal load is connected is a specific breaker, and an overcurrent protection circuit If the overcurrent protection operation occurs a limited number of times, a specific breaker is forcibly tripped by the forced trip circuit provided in the power supply to disconnect the normal load side. If the overcurrent protection circuit is automatically reset again, power can be resumed to the important load side as usual, and lockout of the power supply device does not occur, and the electric vehicle Can continue to operate, minimizing the effects of a ground fault, and if a ground fault has occurred on the critical load side, the overcurrent protection circuit is automatically reset again. Later, an overcurrent will flow again and the power supply will be cut off and the power supply will be locked out.However, if a ground fault accident occurs in a critical load, it should be put in the garage immediately and repaired properly. As a result, the protection operation can be performed by detection, and the reliability of the overcurrent protection operation can be maintained.

According to the second aspect of the present invention, in addition to the first aspect, the overcurrent protection operation can be performed even after the breaker to which the normal load is connected is forcibly tripped in one of the power supply devices. In such a case, it is assumed that a ground fault has occurred in the important load connected to this power supply, and the power supply / reception function between the other power supply is stopped. If a ground fault occurs in the load, the other power supply will be affected, preventing both power supplies from locking out and causing the system to go down, and the power supply connected to a normal load. Alone, the operation can be continued, the influence of the ground fault can be minimized, and the reliability of the system can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a common embodiment of the first and second aspects of the present invention.

FIG. 2 is a flowchart showing an operation when a ground fault of a normal load occurs in the embodiment.

FIG. 3 is a flowchart showing the operation of the above embodiment when an important load ground fault occurs.

FIG. 4 is a circuit diagram of a conventional example.

FIG. 5 is a flowchart showing an operation of a conventional example when a load ground fault occurs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Overhead wire 2,3 Current collector 4,5 Power supply device 6,7 Overcurrent protection circuit 8A, 9A Normal load 8B, 9B Important load 10A, 11A Specific breaker 10B, 11B Breaker 12 Receiving power contactor 13 Receiving power line 14, 15 Supply Electric wires 16, 17 Forced trip circuit 18, 19 Receiving / supplying stop circuit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tomoaki Ishikawa 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation (56) References JP-A-63-100920 (JP, A) JP-A-58- 151825 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60L 1/00-15/42

Claims (2)

(57) [Claims] A power supply device receiving power from an overhead line through a current collector is equipped with a contactless high-speed overcurrent protection circuit having an automatic recovery function, and a breaker having a mechanical contact on a power supply line supplied to a load from the power supply device is provided. In a power supply protection device for an electric vehicle, two breakers having mechanical contacts are connected in parallel to a power supply line from the power supply device, a load is connected to an output side of each breaker, and the high-speed A power supply protection device for an electric vehicle, comprising: a forced trip circuit for giving a forced trip command to a specific one of the two breakers by a limited number of overcurrent protection operations of the overcurrent protection circuit. 2. A contactless high-speed overcurrent protection circuit having an automatic recovery function is mounted on each of a plurality of power supply devices that receive power from an overhead line through a current collector, and a mechanical contact is provided on a power supply line supplied from each of the power supply devices to a load. A power supply protection device for an electric car, wherein a power supply line of the plurality of power supply devices is connected to each other by a power supply line having a power supply / reception contactor. Two breakers each having a passive contact are connected in parallel, a load is connected to the output side of each breaker, and each of the plurality of power supplies is provided with a limited number of times of a high-speed overcurrent protection circuit mounted on the power supply. A forced trip circuit for giving a forced trip command to a specific one of the two breakers by an overcurrent protection operation; A power supply protection device for an electric vehicle, comprising: a power supply / reception stop circuit for detecting an overcurrent protection operation of the high-speed overcurrent protection circuit after a forced trip and prohibiting a power supply / reception operation of the power supply / reception contactor.