Improved Scheme for Single-Ground Fault Suppression Based on Grounded-Fault Transfer Device

摘要

For the sake of reliability of power distribution, medium voltage distribution networks apply small-current earthed mostly. However, traditional resonant earthed methods applied arc suppression coil have poor performance as capacitive current growing rapidly. In order to eliminate single-ground fault effectively, a full-compensation method based on controllable voltage source is therefore proposed and grounded-fault transfer device is applied. Controllable voltage source proposed based on high power electronic devices could inject compensation voltage with specific phase and amplitude into neutral point, which could realize single-ground fault self-extinguish. And grounded-fault transfer device applied in the improved scheme could improve the efficiency of full-compensation method. The verification of the improved scheme for single-ground fault full-compensation is supported by PSCAD/EMTP. Results acquired indicate that the improved scheme for single-ground fault suppression method based on grounded-fault transfer device could eliminate single-ground fault efficiently.