串联电抗器对电力系统短路电流特性影响的研究

Study on influence of series reactor on power system short-circuit current characteristics

合理配置串联电抗器可有效抑制系统短路电流,但同时也会对短路电流特性产生一定影响。结合电网接线和运行状态,研究了串抗配置对电力系统短路电流周期分量、直流分量、冲击电流以及短路电流零偏的影响,分析评估了串抗后断路器的开断及关合能力校核标准。研究结果表明:串抗值越大,短路电流越小,且其对串抗的灵敏度也越小。当母联串抗增大到一定值时,将可能产生零偏现象。安装串抗抑制短路电流时,建议考虑短路电流中直流分量的影响,采用短路全电流有效值作为校核对断路器开断能力的指标。

Reasonable installation of series reactors can effectively limit the short circuit current, but it will also have Some influence on the characteristics of short circuit current. The impacts of series reactors on the periodical component of short-circuit current, DC component, peak current and current zero offset are analyzed, and the verification standard of breaking ability and making capability of circuit breakers are evaluated combined with power grid connection and operation status. The results show that the larger the series reactor is, the smaller the short circuit current, and the sensitivity of short circuit current to series reactor is also smaller. In addition, when the bus tie reactor increases to a certain value, the short-circuit current zero offset will occur. It is also advisable that when the series reactor is installed to restrain the short circuit current, the DC offset may decay much slower that the breaking capability of the circuit breaker be verified by the total short circuit current RMS.