Self-voltage-sharing control method for dynamic charge compensation of multi-fracture vacuum circuit breaker

Abstract

The invention discloses a self-voltage-sharing control method for dynamic charge compensation of a multi-fracture vacuum circuit breaker. According to the method, a sealing ring in a main shielding case of a vacuum arc-extinguishing chamber is vertically connected with a voltage-sharing capacitor, the adsorption of charges by the main shielding case of the vacuum arc-extinguishing chamber is achieved to participate in the counteracting of post-arc unbalanced charges of a contact gap, and then uneven dynamic voltage distribution caused by the post-arc unbalanced charges of the contact gap is compensated, and dynamic self-voltage-sharing of a transient recovery voltage (TRV) in a stable stage is achieved. Control switches S1 and S2 are introduced, and the control switches S1 and S2 are controlled to be discontinuously conducted through real-time detection and judgment to achieve the dynamic self-voltage-sharing control of real-time dynamic charge compensation in different stages of the TRV, so that a real-time dynamic self-voltage-sharing effect is obtained, the dynamic voltage distribution uniformity of the multi-fracture vacuum circuit breaker can be greatly improved, the breakingcapacity of each fracture is exerted to the greatest extent, and the overall breaking capacity of the multi-fracture vacuum circuit breaker is improved.

Description

technical field [0001] The invention belongs to the field of vacuum circuit breakers, and in particular relates to a self-equalizing control method for dynamic charge compensation of multi-fracture vacuum circuit breakers. Background technique [0002] At present, vacuum circuit breakers are widely used in the medium voltage field. Due to the limitation of the saturation effect between the vacuum gap breakdown voltage and the gap distance, the single-break vacuum circuit breaker’s voltage level is generally lower than 145kV. To achieve a voltage level of 363kV and above, it is necessary to use Multiple single-fracture vacuum interrupters are connected in series to form a multi-fracture vacuum circuit breaker. However, due to the existence of stray capacitance in a multi-fracture vacuum circuit breaker, the voltage distribution of each series-connected fracture is uneven, and the static voltage distribution is generally composed of equivalent capacitance parameters. Value cir...

AI Technical Summary

Problems solved by technology

This method requires high control precision, and each fracture is operated asynchronously, which cannot fundamentally eliminate unbalanced charges.

Due to the existence of this unbalanced charge, the dynamic voltage distribution of the multi-fracture vacuum circuit breaker is uneven, especially under the action of the transient recovery voltage, it is easy to cause the vacuum interrupter with high withstand voltage to break down first, resulting in the failure of the multi-fracture vacuum circuit breaker to break.

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