谐波对矢量同步法线路差动保护的影响

变压器励磁涌流带来的谐波会对采用矢量同步法的差动保护带来影响。分析矢量同步方法原理,说明了变压器励磁涌流谐波对线路差动保护矢量同步方法带来的误差原因。理论分析了全波差分傅氏算法和半波差分傅氏算法的异同,并采用这2种算法对同一组数据进行仿真验证。通过理论和实际两方面的对比总结出,对使用矢量同步方法的线路差动保护采用全波差分傅氏算法后可以大大减小谐波带来的同步误差,提高保护装置的可靠性。

Influence of harmonic on line difference protection based on vector synchronization

The harmonic caused by the transformer magnetizing inrush will affect the difference protection based on vector synchronization.Through the principle analysis,reason of the caused errors is illuminated.The full-wave and half-wave Fourier transform algorithms are studied in their similarities and differences,and then applied to the same data for emulation test.The theoretic analysis and the practical application prove that using full-wave Fourier transform algorithm in line difference protection based on vector synchronization will reduce the synchronization error caused by harmonic greatly and improve the reliability of protection device.