and Recovery Voltage at Double-Circuit Transmission Lines
Shang Liqun,Shi Wei
(School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:A new method for calculating secondary arc current and recovery voltage on double-circuit transmission lines by twice-model transformation was proposed. Firstly the phase-quantities of the lines are transformed into the mode-quantities by the transformation matrix T,then these mode-quantities are transformed by the transformation matrix H,thus the twice-modal mathematical model of the transmission lines is established.The steady-state values of the secondary arc current and the recovery voltage can be calculated via this model.The numbers of variables and equations in this model are reduced to half of the once-modal transformation to greatly lower calculation workload. Simulation results for one practical line are coincident with the results by EMTP,which shows that the new twice-modal transformation method provides an alternative approach to calculate the steady-state values of the secondary arc current and the recovery voltage．
Keywords:double-circuit transmission lines;secondary arc current;recovery voltage; twice-modal transformation