Vulnerable line identification and its transmission section search for power system

Three steps are proposed to realize the prevention and control of power system cascading failure: vulnerable line identification, transmission section search and control strategy design. Since the vulnerable line is easily affected by the system disturbance and its removal may cause the power flow transfer in whole power network, a comprehensive index is proposed to identify the vulnerable lines, which applies the impact vulnerability to represent its impact-resistance ability and the transfer vulnerability to represent the damage caused by its removal to system. A method of transmission section search based on the difference coefficient of power transmission distribution factor between transmission lines is proposed to determine whether the removal of a vulnerable line will cause a cascading failure. Therefore, the impact of transmission line removal on whole system can be quickly evaluated by only analyzing its impact on the lines within the transmission section. Results of calculation for the standard IEEE 39-bus system verify the proposed index and method are effective and feasible. ©, 2015, Electric Power Automation Equipment Press. All right reserved.