JPH0965507A - Ac-dc switching circuit of ac-dc dual system electric car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AC/DC switching circuit which can prevent a delay in no-voltage release of a DC voltage detecting relay and prevent a short circuit of a DC power supply even when a short-circuiting failure of a contractor occurs. SOLUTION: A contractor 11A of one circuit and one contact which turns ON in an AC section and OFF in a DC section is provided between the (+) side 6A of a DC output end of an auxiliary rectifier 6 and the (+) side of an input line of an auxiliary circuit 5, while a contractor 1B of one circuit and one contact which turns OFF in the AC section and ON in the DC section is provided between either 6B of AC input ends of the auxiliary rectifier 6 and a grounding device 8. Accordingly, it is unnecessary to use an AC-DC changeover switch being a specific device and the specifications of main circuit equipment can be standardized by the contractors. Even when the contractors fail to operate, no short circuit of a power supply takes place and no effect is produced on other electric cars. Since only necessary minimum rectifying elements are used for checking the reverse voltage of the auxiliary circuit, the power loss in the auxiliary rectifier can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC / DC switching circuit for an AC / DC electric vehicle, and in particular, it does not use an AC / DC converter, which is a special switching device, and has only one ON / OFF function for one circuit. An AC / DC electric vehicle that can prevent a delay in the release operation of the DC voltage detection relay due to the back electromotive force of the auxiliary circuit in the no-voltage section by using a normal contactor that does not have it, and can prevent a DC power supply short circuit even when the contactor has a short circuit failure Of the AC / DC switching circuit.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a connection state of an electric line near an AC / DC switching point, FIG. 4 is a diagram showing a circuit state when a DC section is traveling, and FIG. 5 is a conventional AC / DC. It is a figure which shows the circuit state at the time of AC area traveling of the AC / DC switching circuit of an electric vehicle.

FIG. 3 is a diagram showing a state of connection of a train line near the AC / DC switching point. Between the AC section 13 in which power is supplied from the AC power supply 17 via the train line 1 and the line, and the DC section 14 in which power is supplied from the DC power supply 16 via the train line 1 and the line, There is provided a non-voltage section (dead section) 15 in which a train line 1 that is electrically separated from 1 is installed over several tens of meters.

FIG. 4 is a diagram showing a circuit state of a conventional AC / DC switching circuit of an AC / DC electric vehicle during traveling in a DC section. In the DC section 14, the electric power of the auxiliary circuit is collected from the pantograph 2 which contacts the electric power line 1 to collect electric power, through an AC circuit breaker 3, an AC / DC switch (ADCg) 4, and an AC / DC converter (ADCm) 7.
It is supplied to the auxiliary circuit 5. At this time, the return current on the ground side flows from the auxiliary circuit 5 to the grounding device 8 connected via the auxiliary rectifier 6 and the AC / DC converter 7 (ADCm).

The pantograph 2 includes a DC voltage detecting relay.
(DCVR) 10 is connected, and the AC circuit breaker 3 is turned off by the control circuit 12 when the DC voltage detection relay 10 is released (OFF) at the time of DC side conversion. Therefore, the application of the different voltage due to the forgetting of the switching operation at the AC / DC switching point is detected by the non-voltage section 15 provided at the AC / DC switching point to protect the auxiliary circuit 5 and the like.

FIG. 5 is a diagram showing a circuit state of a conventional AC / DC switching circuit of an AC / DC electric vehicle during traveling in an AC section. In the AC section 13, the electric power of the auxiliary circuit is supplied from the pantograph 2 which contacts the electric power line 1 to collect electric power, through the AC circuit breaker 3 and the AC / DC switch (ADCg) 4, and is stepped down by the main transformer 9. , Rectified by the auxiliary rectifier 6, and AC / DC converter
It is supplied to the auxiliary circuit 5 via (ADCm) 7.

When the counter electromotive force of the auxiliary circuit 5 is directly applied to the DC voltage detecting relay (DCVR) 10, even if the electric vehicle enters the no-voltage section 15, the DC voltage detecting relay (DC
There is a possibility that the VR 10 does not release (OFF) and enters the different voltage section while the AC circuit breaker 3 is turned ON (ON). In this case, each device of the main circuit and auxiliary circuit of the electric vehicle may be damaged.

In order to prevent this phenomenon, conventionally, in the DC section 14, the auxiliary rectifier 6, which is not normally used, is reversely connected to the ground circuit 8 side through the AC / DC converter (ADCm) 7 so as to prevent the backflow. Is diverted as.

[0009]

In the conventional AC / DC switching circuit for an AC / DC electric vehicle, the AC / DC converter 7 is not an ordinary contactor having only one ON / OFF operation function with one contact in one circuit. It used a special AC / DC converter that had the functions of AC on / DC off / AC off / DC on with two circuits and multiple contacts. Therefore, the specifications cannot be shared with the contactors of other main circuits, which is an obstacle to standardization.

Further, since the entire auxiliary rectifier 6 is diverted as the counter electromotive force blocking rectifier element, two rectifier elements are connected in series with the AC side input end of the auxiliary rectifier 6 interposed therebetween. . The withstand voltage of the counter electromotive force blocking rectifying element is sufficient for one series, but in the conventional circuit configuration of two series, the forward voltage drop doubles, and the auxiliary rectifier 6 loses more power than is necessary. Was occurring.

An object of the present invention is to prevent a delay in the release operation of the DC voltage detecting relay in the no-voltage section, prevent a DC power source short circuit even when the contactor has a short circuit failure, and suppress the power loss in the auxiliary rectifier. An object is to provide an AC / DC switching circuit for an electric vehicle.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention uses a DC power source taken in through an AC / DC switch as a power source for an auxiliary circuit in a DC section and directly in an AC section. , In the AC / DC switching circuit of an AC / DC electric vehicle that uses the auxiliary rectifier to rectify the AC power taken through the transformer and use it as the power source for the auxiliary circuit, the (+) side of the DC output end of the auxiliary rectifier and the input line of the auxiliary circuit The first contactor that turns on in the AC section and turns off in the DC section is provided between the (+) side and the (+) side, and the DC is turned off in the AC section between any one of the AC input terminals of the auxiliary rectifier and the grounding device. Second turn on in the section
The present invention proposes an AC / DC switching circuit for an AC / DC electric vehicle equipped with the contactor.

[0013]

According to the present invention, the AC / DC switching circuit is replaced with a special AC / DC converter having a function of AC ON / DC OFF / AC OFF / DC ON with a plurality of two contacts, and one circuit has one contact / ON.
Two normal contactors that have only the function of off operation are used, and the (+) side of the auxiliary rectifier DC output terminal and the auxiliary circuit 8
The first contactor is provided between the DC power supply input line and the (+) side, and the second contactor is provided between either one of the auxiliary rectifier AC input ends and the ground line.

In the DC section, the first contactor on the DC output end side of the auxiliary rectifier is opened (OFF) and the second contactor on the AC input end side (ground side) is turned on (ON). The second contactor connects between the auxiliary rectifier AC input and the grounding device and forms a path for the auxiliary circuit current to the DC power supply (-) side. Some of the rectifying elements of the auxiliary rectifier function as reverse blocking rectifying elements of the auxiliary circuit, and some of the other rectifying elements of the auxiliary rectifier have a
Function as a reverse blocking rectifying element that prevents a short circuit of the DC power supply when the contactor has a short circuit failure.

In the AC section, the first contactor on the DC output end side of the auxiliary rectifier is turned on (ON) and the second contactor on the AC input end side (ground side) is opened (OFF). The first contactor connects the DC output terminal of the auxiliary rectifier and the DC power supply (+) side input line of the auxiliary circuit, and supplies electric power from the auxiliary rectifier to the auxiliary circuit. The auxiliary rectifier operates as a normal rectifier, rectifies the power from the main transformer and supplies it to the auxiliary circuit.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a circuit condition when an AC / DC switching circuit for an AC / DC electric vehicle according to an embodiment of the present invention is running in a DC section, and FIG. 2 is an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention. It is a figure which shows the circuit state at the time of driving | running | working the alternating current area in an Example.

In this embodiment, in place of the special AC / DC converter 7 having a function of AC ON / DC OFF / AC OFF / DC ON, which has been conventionally used with two-circuit multiple contacts, the DC output terminal of the auxiliary rectifier 6 is replaced. Between the (+) side 6A of the auxiliary circuit 5 and the (+) side of the input line of the auxiliary circuit 5, a contactor 11A that is turned on in the AC section and turned off in the DC section is provided, and either one of the AC input terminals of the auxiliary rectifier 6 is provided. A contactor 11B that is turned off in the AC section and turned on in the DC section is provided between (6B in this case) and the grounding device 8.

FIG. 1 is a diagram showing a circuit state during traveling in a DC section in an embodiment of an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention. In the direct current section, the electric power of the auxiliary circuit comes from the pantograph 2 which collects electricity by contacting the electric train line 1.
It is supplied to the auxiliary circuit 5 via the AC circuit breaker 3 and the AC / DC switch 4. At this time, the return current on the ground side is the auxiliary circuit 5
To the grounding device 8 via the auxiliary rectifier 6 and the AC / DC conversion contactor 11B.

This return current passes through a part of the rectifying element 6C of the auxiliary rectifier 6, but when there is a DC power supply 16 and the auxiliary circuit 5 is consuming electric power, it goes in the forward direction of the rectifying element 6C. Since the current flows, the auxiliary circuit 5 operates normally without being affected by the rectifying element 6C.

The AC / DC electric vehicle enters the non-voltage section 15,
When the DC power supply voltage is lost, the reverse voltage of the auxiliary circuit 5 causes a current to flow in the reverse direction via the DC voltage detection relay (DCVR) 10, but in the reverse direction to the rectifying element 6C. Therefore, the flow of current is blocked.

As described above, since the current due to the reverse voltage of the auxiliary circuit 5 does not flow into the DC voltage detecting relay (DCVR) 10, the DC voltage is detected even if it enters the non-voltage section 15 without performing the AC / DC switching operation. The relay (DCVR) 10 operates immediately to prevent application of different voltage.

Further, in the DC section, when the AC / DC conversion contactor 11A on the (+) side 6A of the auxiliary rectifier DC output terminal has a short circuit failure, a part of the rectifying element 6D of the auxiliary rectifier 6 is used as the DC power source of the auxiliary circuit 5. Since it is connected in the reverse direction between the (+) side and the grounding device 8 and blocks the inflow of current, it is possible to prevent overcurrent due to a short circuit of the DC power supply.

Further, among the rectifying elements of the auxiliary rectifier 6, only the minimum necessary element such as 6C or 6D is used as the auxiliary circuit 5.
Since the auxiliary rectifier 6 is used as the reverse voltage blocking rectifier element, the power loss in the auxiliary rectifier 6 can be greatly suppressed as compared with the conventional AC / DC switching circuit in which the entire auxiliary rectifier 6 is used for blocking the reverse voltage.

FIG. 2 is a diagram showing a circuit state during traveling in an AC section in an embodiment of an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention. In the AC section, the electric power of the auxiliary circuit is collected from the pantograph 2 which contacts the electric power line 1 to collect the electric power.
It is supplied through the AC breaker 3 and the AC / DC switch 4, is stepped down by the main transformer 9, is rectified into DC by the auxiliary rectifier 6, and is supplied to the auxiliary circuit 5 through the AC / DC conversion contactor 11A.

[0025]

According to the present invention, one circuit and one contact are turned on / on.
It is possible to build an AC / DC switching circuit for an AC / DC electric vehicle by using only two normal contactors that only have the function of off operation, and there is no need to use an AC / DC converter that is a special device. Can be standardized to use only a contactor, which is advantageous for standardization. Further, even if the contactor fails in the DC section, the power supply short circuit does not occur, and it does not affect other electric vehicles connected to the same power supply. Furthermore, among the rectifying elements of the auxiliary rectifier, only the minimum necessary elements are used as the reverse voltage blocking rectifying element of the auxiliary circuit, so compared to the conventional AC / DC switching circuit that uses the entire auxiliary rectifier for blocking the reverse voltage. The power loss in the auxiliary rectifier can be suppressed.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit state during traveling in a DC section in an embodiment of an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention.

FIG. 2 is a diagram showing a circuit state during traveling in an AC section in an embodiment of an AC / DC switching circuit for an AC / DC electric vehicle according to the present invention.

FIG. 3 is a diagram showing a connection state of a train line near an AC / DC switching point.

FIG. 4 is a diagram showing a circuit state of a conventional AC / DC switching circuit of an AC / DC electric vehicle during traveling in a DC section.

FIG. 5 is a diagram showing a circuit state of a conventional AC / DC switching circuit of an AC / DC electric vehicle when traveling in an AC section.

[Explanation of symbols]

 1 Train line (power line) 2 Current collector (pantograph) 3 AC breaker 4 AC / DC switcher (ADCg) 5 Auxiliary circuit 6 Auxiliary rectifier 6A Auxiliary rectifier DC output terminal 6B Auxiliary rectifier AC input terminal 6C Auxiliary rectifier element 6D Auxiliary Rectifier Rectifier element 7 AC / DC converter (ADCm) 8 Grounding device 9 Main transformer 10 DC voltage detection relay (DCVR) 11A AC / DC conversion contactor 11B AC / DC conversion contactor 12 Control circuit 13 AC section 14 DC section 15 No-voltage section (Dead section) 16 DC power supply 17 AC power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshio Numano Toshio Numano 1-6-5 Marunouchi, Chiyoda-ku, Tokyo Within East Japan Railway Company (72) Inventor Hiroshi Amiko 1-6-6 Marunouchi, Chiyoda-ku, Tokyo # 5 East Japan Railway Company (72) Inventor Yoshiyuki Higashi 1-6-5 Marunouchi, Chiyoda-ku, Tokyo East Japan Railway Company

Claims (1)

[Claims] 1. In a DC section, a DC power source taken in via an AC / DC switch is directly used as a power source for an auxiliary circuit, and in an AC section, AC power taken in via an AC / DC switch and a transformer is rectified by an auxiliary rectifier. In an AC / DC switching circuit of an AC / DC electric vehicle used as a power source for an auxiliary circuit, the switch is turned on in an AC section between the (+) side of the DC output terminal of the auxiliary rectifier and the (+) side of the input line of the auxiliary circuit. A first contactor that is turned off in the direct current section is provided, and a second contactor that is turned off in the alternating current section and turned on in the direct current section is provided between one of the alternating current input terminals of the auxiliary rectifier and the grounding device. AC / DC switching circuit for AC / DC electric cars.