【摘要】 当交直流混联电网的联络线中有故障发生时，直流逆变侧电气故障特征和无穷大交流电源截然不同，难以保证传统交流保护方法的可靠与灵敏。因此提出了一种基于Bhattacharyya系数和Pearson相关系数的交直流混联电网电压波形相似度纵联保护方法，线路两侧的保护单元对各自的测量电压和通过计算得到的参考点参考电压波形相似性进行比较。综合Pearson相关系数和Bhattacharyya系数对待判断的两电压波形相似度进行判断，此后对线路两端保护装置的故障区域相似性判断结果采用纵联保护逻辑进行比较，从而实现对全线范围内区内外故障进行可靠识别与判断。PSCAD仿真结果表明，所提方法可以准确识别交直流混联电网联络线故障，具有较高的可靠性和良好的适用性。更多还原

【Abstract】 When a fault occurs on the tie line of AC/DC hybrid power system,the electrical fault characteristics on the DC inverter side are different from those of an infinite AC power supply.The sensitivity and reliability of traditional protection methods will be hard to guarantee.In this paper,a longitudinal protection method of AC/DC hybrid power grid for voltage wave similarity based on Bhattacharyya coefficient and Pearson correlation coefficient is proposed.The wave similarity of the measuring voltage and the calculated reference point reference voltage on both sides is compared. The voltage wave similarity is judged by combining Pearson correlation coefficient and Bhattacharya coefficient. After that,the longitudinal comparison of the similarity judgment results on both sides will be conducted.The identification and judgment of internal and external faults in the entire line can be achieved reliable.The PSCAD simulation results demonstrate that the proposed method can accurately identify faults on the tie line of the AC/DC hybrid power system,exhibiting high reliability and applicability.更多还原