Capacitor switching fault protection method and system based on three-phase cooperative control

The capacitor switching method using three-phase coordinated control solves the resonance problem caused by single-point switch failure in the existing technology, improves the safety and reliability of the capacitor system, extends equipment life and provides predictive maintenance.

CN121840532APending Publication Date: 2026-04-10XINXIANG YISHENG ELECTRONIC TECH CO LTD
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Patent Information

Application Number
CN202511908502.9
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-12-17
Publication Date
2026-04-10

AI Technical Summary

Technical Problem

The existing capacitor switching scheme of "two-phase control, one-phase direct connection" has a safety defect: due to the failure of a single-point switch, an LC series resonant circuit is formed, which cannot be identified and cut off, resulting in damage to the capacitor and power grid equipment.

Method used

A three-phase coordinated control method is adopted, in which all three-phase switching elements are placed under the intelligent control unit, defining the main control phase and the backup coordinated phase. Through fault identification process and coordinated protection operation, the capacitor circuit is effectively disconnected in case of fault, preventing resonance accidents.

Benefits of technology

It improves the operational safety and fault tolerance of the capacitor switching system, extends the system's service life, and enables predictive maintenance and proactive protection.

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Abstract

The invention relates to the technical field of reactive compensation of a power system, and discloses a capacitor switching fault protection method and system based on three-phase cooperative control, and the method comprises the following steps: S1, enabling an A-phase switch element, a B-phase switch element and a C-phase switch element in a three-phase circuit to be under the independent control of an intelligent control unit; s2, the intelligent control unit predefines at least two phases in the three phases as main control phases and defines the remaining phase as a standby cooperative phase; s3, when a conventional capacitor switching operation is executed, the intelligent control unit controls the standby cooperative phase to keep a closed state; s4, when the switching instruction is a disconnection instruction, starting a fault identification process; and S5, when it is judged that the fault phase exists, the intelligent control unit immediately executes collaborative protection operation. According to the invention, by setting the main control phase and the standby cooperative phase, at least two phases of circuits can still be cooperatively disconnected when a single switch fails, so that the formation condition of a resonant circuit is thoroughly blocked.
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