As the voltage level of the power system increases, the DC component influence on the breaking capacity of the circuit breaker has been closely concerned. However, there are few studies on the calculation method of DC component of short circuit current in the circuit breaker branch. In this paper, a calculation method is proposed for the DC component of branch short-circuit current and its decay time constant based on transfer impedance. Firstly, in the case of knowing the impedance matrix of the original network and considering the characteristics of the network when the system is short-circuited, the network is transformed based on the principle of forming the node impedance matrix using the branch-adding method.Then, the transformed network can easily calculate the DC component of the short-circuit current and the decay time constant of each branch. In addition, a unified algorithm for forming the node impedance matrix is concluded when considering the changes of the network topology. It has the advantages of fast calculation speed, clear physical concept, and it is easy to program so as to achieve scanning calculations. The accuracy of the proposed method is verified by EMTP simulation. Compared with results from PSS/E, the superiority of the proposed method is also verified.
曹炜,张正,陈春阳,张捷.支路短路电流直流分量及衰减时间常数计算方法[J].电力科学与技术学报,2021,(2):31-39. Cao Wei, Zhang Zheng, Chen Chunyang, Zhang Jie. Study on calculation methods for DC component and decay time constant of branch short circuit current[J]. JOURNAL OF EIECTRIC POWER SCIENCE AND TECHNOLOGY,2021,(2):31-39.复制