Short-circuit current zero-point prediction method and short-current current phase selection breaking control method

Abstract

The invention discloses a short-circuit current zero-point prediction method and a short-current current phase selection breaking control method. The short-current current phase selection breaking control method comprises: S1, a current signal is collected in real time and whether a short-circuit fault occurs is determined; if so, a S2 is executed; and if not, current signal collection is carried out continuously; S2, a short-circuit current is processed by using a similar-prony method to obtain a short-circuit current zero point; S3, according to the short-circuit current zero point, opening motion time of a circuit breaker, and optimal arcing time, delay time of a distance target phase is obtained; S4, whether a relay protection instruction arrives is determined; if so, switch breaking is carried out directly; and if not, delay counting down is carried out; S5, whether the delay counting time is zero is determined; if so, a S6 is carried out; and if not, counting down is carried out continuously; S6, after delay ends, whether a relay protection instruction reaches is determined again; if so, a S7 is carried out; and if not, the breaking operation is withdrawn; and S7, disconnecting of a circuit breaker is controlled and phase selection breaking is realized after the optimal arcing time.

Description

technical field [0001] The invention belongs to the field of intelligent electrical appliances in a power system, and more specifically relates to a short-circuit current zero-point prediction method and a short-circuit current phase-selection breaking control method. Background technique [0002] Phase selection control technology is an intelligent control technology that controls the switch to complete closing or opening in the optimal (expected) voltage or current phase according to the load status. For conventional equipment such as capacitor banks and reactor banks, the electrical signal of the system changes periodically, and the target phase is easy to determine. Therefore, the development of corresponding phase selection products is relatively mature and has been widely used in power systems. However, there is no effective implementation scheme for the phase-selection breaking technology of short-circuit fault current. [0003] The phase-selection breaking technolog...

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Problems solved by technology

[0008] In view of the defects of the prior art, the purpose of the present invention is to provide a short-circuit current zero-point prediction method, aiming to solve the problem in the prior art that the short-circuit current zero-point prediction error is large due to inaccurate model description

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