振荡闭锁期间不对称故障的快速识别方法

针对基于负序电流幅值加零序电流幅值与正序电流幅值之比的识别方法(简称序电流比值法)存在有时开放保护的延时太长的问题,提出了基于负序电流、零序电流幅值和与正序电流幅值之比的变化率的识别方法(简称比值变化率法)。论文以一个双端电源电网为例,对比值变化率法与序电流比值法进行了对比研究。结果表明,文章提出的比值变化率法除个别情况比序电流比值法开放保护的时间稍长外,绝大多数情况都比序电流比值法开放保护的时间要短得多。文章建议,将比值变化率法和序电流比值法共同作为振荡中发生不对称短路故障的综合判据,这样可以大大提高振荡中发生不对称短路故障时开放保护的速度。

Fast identification of asymmetry fault during power swing blocked

That the earlier method of value of negative-sequence current module and zero-sequence current module divid positive-sequence current module delayes longer time sometimes is indicated.The paper proposes a method of ratio of value of negative-sequence current module and zero-sequence current module dividing positive-sequence current module in order to quickly identifies asymmetry fault during power swing.The paper uses a double sources electrical network as an example,and a research of comparing the proposed method with the ealier method for the delay of enabling relay protection is established.The result indicates that the proposed method has much more short delay than ealier method in bulk circumstances except for individual.It suggests that a new synthesis criterion of two methods for enabling relay protection may be more availabile,both of one acts and the relay protections are enabled.In this way,the speed of enabling relay protection would be advanced enormously during power swing blocked.