A fast protection method for series capacitor overvoltage in power system

Abstract

A power system series capacitor overvoltage fast protection method, the protection circuit includes a series capacitor bank and an MOA branch connected in parallel with it, a voltage sensor and a switch branch; the MOA branch includes an MOA and a current sensor arranged in series, and the switch branch includes The damping circuit and the switching device arranged in series; the main circuit where the series capacitor bank is located is provided with a main circuit current sensor and a main circuit voltage sensor, and the main circuit current sensor, the main circuit voltage sensor, the current sensor and the voltage sensor are connected to the input terminal of the controller , the output of the controller is connected to the switching device. The protection method realizes the main protection of the overvoltage of the series capacitor bank and the thermal collapse of the MOA through the monitoring and rapid identification of the MOA branch current; through the monitoring of the main circuit current and the voltage across the series Fallback protection for MOA thermal crashes. The invention is simple, direct, fast and reliable.

Description

technical field [0001] The invention relates to the field of power system series compensation, in particular to a fast overvoltage protection method for series capacitors in a power system, which is mainly used in power systems and other industrial power systems for long-line, low-voltage, high-loss transmission and distribution lines for loss reduction regulation pressure and increase the transmission power. Background technique [0002] When a short-circuit fault occurs on the load side of the power system series compensation device, a high power frequency overvoltage will appear on the series capacitor. In order to avoid the damage of the series capacitor caused by this overvoltage, it is necessary to quickly protect it. [0003] The first device for overvoltage protection of series capacitors is the MOA. Due to the thermal capacity of the MOA and its own cost limitations, once the MOA operates, its safe working time is very limited, so it is necessary to set the second p...

AI Technical Summary

Problems solved by technology

[0004] The limitations of the prior art methods are: (1) the rapid identification of the acquired signal needs to be realized through a complex special algorithm, and misjudgment is prone to occur under the action of electromagnetic interference or transient interference signals; (2) the capacitor bank second The overvoltage protection device essentially protects the MOA, that is, it needs to quickly bypass the activated MOA, so the above signal is only an indirect signal, not a direct signal for the capacitor bank or MOA to request protection.

Images