一种基于故障电流特性的反孤岛保护技术

An anti-islanding protection technique based on the characteristics of faulted current

提出了一种基于故障电流特性的分布式发电系统孤岛检测技术,该方法通过人为制造分布式发电机出口端短路,进而产生一种能够有效反应系统阻抗变化的短路脉冲电流,通过对该电流的监测分析即可实时判定分布式电源是否处于孤岛状态。推导出了短路脉冲电流的理论表达式,通过仿真分析建立了判定孤岛状态的理论判据,并就信号间的干扰以及对系统电能质量的影响进行了分析,理论和仿真分析都验证了该孤岛检测技术的有效性。

A new anti-islanding protection technique was proposed based on the characteristic of faulted current. This method artificially created short circuit in the port of distributed generator to produce a faulted pulse current, which could effectively reflect the change of the system impedance. The islanding status could be judged through monitoring and analyzing the faulted pulse current. The equation of the faulted pulse current was derived, and the criteria for the is-landing determination were set up. Disturbance between signals and the effect on the system were also analyzed. Final-ly, this method was validated by theoretical analysis and computer simulation.