基于模域回路理论的配网电缆-架空线混合线路重合闸过电压特性分析

The amplitude and dominant frequency characteristics of reclosing overvoltage with different cable proportions in cable-overhead hybrid line were studied based on the wave propagation in modal domain. The propagation constants of 10kV cable and overhead line (OHL) in modal domain circuit were obtained through modal transformation. Using electro-magnetic transients program (EMTP), an asymmetrical line model was established, and the variation tendency of statistical overvoltage under different cable proportions was investigated. The results show that statistical values vary non-monotonically and a minimum value appears when the cable proportion increases. The results based on voltage propagation in modal domain are consistent with those calculated by EMTP. This method can also be applied in hybrid lines with different proportions since the propagation constants are not influenced.