Arc-extinguishing voltage limiting device based on electronic switch

Abstract

The invention discloses an arc-extinguishing voltage limiting device based on an electronic switch, belonging to the technical field of a power distribution network. The device comprises a high voltage isolation electronic switch, a controllable combined voltage limiter, a voltage sensor and a microcomputer controller, wherein the high voltage isolation electronic switch consists of a switching transformer and an electronic control switch; the controllable combined voltage limiter consists of a zinc oxide non-liner resistor and a quick vacuum contactor; a primary of the switching transformer is connected with the primary of the voltage sensor in parallel, then connected with the controllable combined voltage limiter in parallel and connected between a system bus and the ground; a secondary of the switching transformer is connected with a turn-off quick thyristor by a rectification circuit; the control end of the quick thyristor is connected with the control output end of the microcomputer controller; and the input end of the microcomputer controller is connected with the secondary of the voltage sensor. The arc-extinguishing voltage limiting device is suitable for 6 kV, 10 kV and 35 kV neutral-point non-effectively grounded systems, can effectively inhibit ground arc and different overvoltages of the power system, and has the characteristics of quick action, flexible operation, safety and stability.

Description

technical field [0001] The invention relates to a device in the technical field of power distribution network, in particular to a rapid arc extinguishing voltage limiting device based on an electronic switch. technical background [0002] When a single-phase intermittent arc-flash ground fault occurs in the neutral point indirect grounding system, due to the repeated extinguishment and re-ignition of the unstable intermittent arc, high frequency will be caused on the inductance-capacitance loop of the fault phase and the non-fault phase. Oscillating overvoltage, this overvoltage is formed by the continuous accumulation and redistribution of charges on the capacitance of the system to the ground. great. In order to eliminate arc light grounding, at present, two measures are mainly adopted: installing arc suppression coil at the neutral point of the system and directly grounding the busbar. The arc suppressing coil not only cannot suppress the arc grounding overvoltage, but ...

AI Technical Summary

Problems solved by technology

The arc suppression coil not only cannot suppress the arc grounding overvoltage, but sometimes increases the magnitude of the overvoltage

The direct grounding of the busbar is to quickly convert the arc grounding to the bus metal grounding through the vacuum switch when the arcing grounding occurs. Since the arcing grounding overvoltage has occurred within 20mS of grounding, and the action time of the contactor is often tens of milliseconds, it is not effective. On the other hand, due to the complexity of arc grounding, the normal phase will be mistakenly closed, resulting in a short circuit between two phases

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