Abstract: To solve the accurate calculation problem of secondary arc current and recovery voltage in non-complete-phase operation after single-phase grounding fault of double-circuit line with shunt reactor and neutral reactor, this paper used eigen-model decomposition method to decouple zero sequence parameter in double-circuit line, and proposed the formula for non-complete-phase operation of double-circuit line based on its measured parameters: positive/negative sequence impedance, electrical susceptance, zero sequence self-impedance and mutual impedance, zero sequence self-susceptance and mutual susceptance. The results show that the calculation result of secondary arc current and recovery voltage at fault point can provide a reliable basis for the parameter determination of neutral reactor in double-circuit line, which is valuable to engineering application.

Key words: double circuit, fault calculation, neutral reactor, eigen-model, distribute parameter