High voltage and high current zero-phase switch and its control method

Abstract

The invention provides a high-voltage, high-current zero-phase switch and a control method, comprising: two or more switch unit modules connected in series, the switch unit module is composed of a main switch circuit, an auxiliary switch circuit, a power supply and a voltage equalizing circuit unit and connected to the main switch The circuit is composed of current transformers, the auxiliary switch circuit and the power supply and the voltage equalizing circuit unit are connected in parallel at both ends of the main switch, the output of the current transformer is connected to the power supply and the voltage equalizing circuit unit, and the power supply and the voltage equalizing circuit unit are switch control and communication circuit units Provide power supply, switch control and communication circuit unit to control the closing or opening of the main switch and auxiliary relay. The high-voltage, high-current zero-phase switch of the present invention uses an air contact switch to realize a high-voltage switch that only a vacuum switch or an SF6 switch can realize before. Since the contacts do not need vacuum or SF6 protection, the cost of the switch and the maintenance cost are lower, and There is no inrush current when the switch operates, no arcing occurs, and no pollution to the power grid.

Description

technical field [0001] The invention relates to the field of electrical load switches in electrical engineering, in particular to a high-voltage and high-current phase switch. Background technique [0002] Load switches and circuit breakers are essential components of power supply and distribution systems, used to switch on or off power. Traditional load switches and circuit breakers are closed or disconnected by mechanical contacts. Due to the long contact stroke of high-voltage switches, arcing and arc re-ignition when the switch contacts are disconnected are difficult problems to solve. Traditional The switch uses various physical arc extinguishing methods to reduce and avoid ignition when the switch contacts are closed and arcing when the switch contacts are disconnected. From the principle of arc extinguishing and the level of voltage used, there are gas-generating arc extinguishing, vacuum arc extinguishing, oil arc extinguishing, SF6 arc extinguishing, etc. Only when...

AI Technical Summary

Problems solved by technology

[0005] Traditional switches are single-contact, because the parallel connection of multiple switches cannot solve the current sharing problem of each switch branch. The increased current accelerates the destruction of all switching branches

For a single-contact switch, the greater the current, the more complicated the operating mechanism of the contact, which also causes the cost of the contact operating mechanism to increase and the reliability to decrease.

On the other hand, when the current is very large, even the skin effect of power frequency alternating current cannot be ignored, and the increase of wiring and contact resistance caused by the skin effect of the single contact switch at high current is also difficult to solve

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