计算同杆双回输电线路潜供电流与恢复电压的二次模方法

Twice-Modal Transformation Method for Calculating Secondary Arc Current and Recovery Voltage at Double-Circuit Transmission Lines

提出了利用二次模变换计算同杆双回输电线路潜供电流与恢复电压稳态值的方法.该方法首先利用变换矩阵T进行相模变换,将相量转化为模量,在此基础上再利用变换矩阵H进行第二次模变换,将一次模量转化为二次模量,然后在二次模域中建立计算潜供电流与恢复电压的数学模型.该模型与一次模方程相比,方程和未知数的个数减少了一半, 使得计算量减少,且易于编程实现.对某实际线路进行了计算,其结果与EMTP计算结果一致,表明此方法为进行潜供电流和恢复电压稳态计算提供了另一种途径和选择.

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.