Analysis on Surge Current Characteristics of Electromagnetic Closed-Loop Operation in 750 kV/220 kV Power Grid

It is especially important to study the impact of surge current on electromagnetic closed-loop operation in the EHV power grid. Based on the 750 kV/220 kV closed-loop operation practice of the Xinjiang Bazhou 750 kV substation, a simplified model of surge current is established. The main factors that impact the surge current are analyzed, including voltage difference, phase angle difference and total impedance, and their relations with the surge current are studied. Furthermore, the scheme of closed-loop operation is formulated according to the grid structure of local power system so as to realize the operation. The measured characteristics of surge current are consistent with the theoretical conclusions, which can provide guidance for other grid closed-loop operations.