CN210668160U

CN210668160U - Medium-voltage isolating switch

Info

Publication number: CN210668160U
Application number: CN201921370592.0U
Authority: CN
Inventors: 林永林
Original assignee: Guangzhou Tongkai Electrical Equipment Co ltd
Current assignee: Guangzhou Tongkai Electrical Equipment Co ltd
Priority date: 2019-08-22
Filing date: 2019-08-22
Publication date: 2020-06-02
Anticipated expiration: 2029-08-22

Abstract

The utility model provides a medium voltage isolator, including conductive contact, semiconductor switch bridge and controlling means, the semiconductor switch bridge connects in parallel at conductive contact's both ends for the high tension current of buffering semiconductor switch bridge, controlling means control semiconductor switch bridge only switches on at conductive contact closure or short time during the disconnection. Specifically, the current of the conductive contact is detected by the current sensor through the control device, each gate of the semiconductor switch bridge is controlled according to the current direction, and the capacitor is charged to buffer the arc which is originally required to be generated by the conductive contact. This medium voltage isolator can be through the semiconductor switch bridge and at conductive contact both ends, and the semiconductor switch bridge can carry out the charge and discharge of short time when conductive contact's closure and opening, and the electric arc and the steady current conduction rate that need produce originally are closed or the process of opening to effectual buffering conductive contact.

Description

Medium-voltage isolating switch

Technical Field

The utility model relates to an electrical switching equipment technical field especially relates to a medium voltage isolator.

Background

A disconnector is a device commonly used in electric circuits which can be changed in its open or closed state by a front operation or a side operation. In medium-high voltage ac circuits, although the circuit can be protected by the disconnector, the disconnector is prone to arcing when opened or closed. It is desirable to open or close the disconnector without arcing as much as possible and to stabilize the rate at which the current is conducted.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is just to provide a can cushion and produce electric arc and can stabilize current conduction rate's medium voltage isolator when opening or closing in order to solve above-mentioned problem.

The utility model provides a technical scheme that its technical problem adopted is:

a medium voltage isolating switch comprises a conductive contact, a semiconductor switch bridge and a control device, wherein the semiconductor switch bridge is connected in parallel at two ends of the conductive contact and used for buffering high-voltage current of the semiconductor switch bridge, and the control device controls the semiconductor switch bridge to be conducted for a short time only during the closing or opening period of the conductive contact.

Furthermore, the device also comprises a current sensor, wherein the detection end of the current sensor is arranged at one end of the conductive contact, the output end of the current sensor is connected to the control device, and the control device controls the conduction of the semiconductor switch bridge according to the signal of the current sensor.

Further, the semiconductor switch bridge is formed by four semiconductor switches and a capacitor bridge, and two semiconductor switches with reverse current directions are switched on according to the current direction detected by the current sensor.

Further, the semiconductor switch bridge has a plurality, and the plurality of semiconductor switch bridges are connected in series.

Further, an inductor is connected in series with the tail end of the semiconductor switch bridge.

The utility model has the advantages that:

through adopting above-mentioned technical scheme, this middling pressure isolator can be through the semiconductor switch bridge and at conductive contact both ends, and the semiconductor switch bridge can carry out the charge and discharge of short time when conductive contact's closure and opening, and the electric arc and the steady current conduction rate that need produce originally during the process of effectual buffering conductive contact is closed or is opened.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is a basic circuit diagram of the isolating switch of the present invention;

FIG. 2 is an equivalent simplified circuit diagram of the circuit diagram of FIG. 1;

FIG. 3 is another equivalent simplified circuit diagram of the circuit diagram of FIG. 1;

fig. 4 is a circuit diagram of the optimized scheme of the isolating switch of the invention.

Reference numerals: 1. a conductive contact; 2. a semiconductor switching bridge; 21. a semiconductor switch; 22. a capacitor; 3. a control device; 4. a current sensor; 5. an inductor.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and can implement the present invention, but the embodiments are not to be construed as limiting the present invention.

As shown in fig. 1, a medium voltage disconnector comprises a conductive contact 1, a semiconductor switching bridge 2 connected in parallel across the conductive contact for buffering high voltage currents of the semiconductor switching bridge, and a control device 3 controlling 3 the semiconductor switching bridge to be on for only a short time during the closing or opening of the conductive contact.

The medium voltage isolating switch is aligned with current by utilizing a semiconductor switch bridge 2, a conductive contact 1 of the conductive current is connected with the semiconductor switch bridge 2 in parallel, charging and discharging are carried out according to the closing and opening of the conductive contact 1, and only one side is conducted to keep a bypass mode. After that, when the conductive contact 1 has stabilized, the semiconductor switching bridge 2 is completely opened and the current charging of the semiconductor switching bridge 2 is stopped. The semiconductor switch bridge 2 can effectively buffer the arc that the conductive contact 1 would otherwise need to generate during the process of closing or opening.

As an example, the conduction of the semiconductor switching bridge 2 is switched on by the current sensor 4 detecting the current signal of the conductive contact 1. Specifically, the semiconductor switch bridge 2 is formed by bridging four semiconductor switches 21 and a capacitor 22, and the four semiconductor switches 21 are turned on only one side of two semiconductor switches 21 in a reverse current direction and are not turned on only one side of two semiconductor switches 21 in a forward current direction according to the closing and opening of the conductive contact 1 and the direction of current passing through the conductive contact 1 to maintain the bypass mode.

Fig. 1 is a circuit diagram of the embodiment, and fig. 3 is an equivalent circuit diagram of fig. 1, which cannot be implemented specifically due to the voltage-withstanding performance of the components, but can be used as an analog circuit diagram of fig. 1. In this circuit, the semiconductor switch bridge 2 has four semiconductor switches S1, S2, S3, S4 which are opened and closed by the control device 3. The control device 3 detects the current of the conductive contact by the current sensor 4, controls each gate of the semiconductor switch bridge 2 according to the current direction, and is charged by the capacitor C to buffer the arc that originally needs to be generated by the conductive contact 1.

When the semiconductor switch bridge 2 receives a command, for example, when a current flows from the left side to the right side of fig. 1, first, the semiconductor switches S2 and S4 are turned on. The conductive state is maintained until the conductive contact 1 is stably connected or disconnected, the semiconductor switch bridge 2 is closed, and the charge of the capacitor C is left and discharged to the direction of the current flowing to the load in the circuit again. Therefore, the inductor 5 can be connected in series to the tail end of the semiconductor switch bridge 2, and the charge of the capacitor C is consumed by the inductor L and is not applied to the load, thereby preventing the pulse current from rushing into the load. Fig. 2 is an equivalent circuit diagram of a current flowing from the left side to the right side of fig. 1, for reference. Similarly, when current flows from the right side to the left side of the figure, the semiconductor switches S1 and S3 are turned on. Bidirectional turn-on may be achieved by selecting a pair of semiconductor switches S1 and S3, S2 and S4 current for the capacitance C.

Because the impact on the capacitor C as a buffer is large, a single capacitor C can not bear the voltage, and a plurality of capacitors can be connected in series to increase the withstand voltage of the capacitor. However, since the semiconductor switch bridge 2 is generally integrated, as shown in fig. 4, a plurality of semiconductor switch bridges 2 are connected in series to achieve the purpose of connecting a plurality of capacitors in series. However, the capacitance value is not influenced by the number of the capacitors C connected in series.

The above embodiments of the present invention are not right the utility model discloses the limited protection scope, the utility model discloses an embodiment is not limited to this, all kinds of basis according to the above-mentioned of the utility model discloses an under the above-mentioned basic technical thought prerequisite of the utility model, right according to ordinary technical knowledge and the conventional means in this field the modification, replacement or the change of other multiple forms that above-mentioned structure made all should fall within the protection scope of the utility model.

Claims

1. A medium voltage isolator, comprising: the high-voltage circuit breaker comprises a conductive contact, a semiconductor switch bridge and a control device, wherein the semiconductor switch bridge is connected in parallel at two ends of the conductive contact and used for buffering high-voltage current of the semiconductor switch bridge, and the control device controls the semiconductor switch bridge to be conducted for a short time only in the period that the conductive contact is closed or disconnected.

2. A medium voltage disconnector according to claim 1, characterized in that: the current sensor is arranged at one end of the conductive contact, the output end of the current sensor is connected to the control device, and the control device controls the conduction of the semiconductor switch bridge according to signals of the current sensor.

3. A medium voltage disconnector according to claim 2, characterized in that: the semiconductor switch bridge is formed by bridging four semiconductor switches and a capacitor, and two semiconductor switches with reverse current directions are selected to be switched on according to the current direction detected by the current sensor.

4. A medium voltage disconnector according to any one of claims 1-3, characterized in that: the semiconductor switch bridge has a plurality of semiconductor switch bridges, and the plurality of semiconductor switch bridges are connected in series.

5. A medium voltage disconnector according to any one of claims 1-3, characterized in that: and the tail end of the semiconductor switch bridge is connected with an inductor in series.

6. A medium voltage disconnector according to claim 4, characterized in that: and the tail end of the semiconductor switch bridge is connected with an inductor in series.