Ring-shaped DC Distribution Network Protection Scheme Research Based-on Voltage Prediction

Abstract

In this paper, it researches the DC-ring distribution network protection scheme. Firstly, it analyzes the fault characteristics of the voltage source converter (VSC) during the DC line-to-ground. Secondly, it proposes a DC distribution network protection scheme based-on local measurement. The quadratic time-varying function is utilized to predict the line-side voltage in case of failure. The difference between the predicted voltage and the measured voltage on the line side in case of failure is utilized as the primary protective action criterion. Under voltage protection is utilized as backup protection in DC ring distribution network to guarantee safety and stability in case of failure. And the overcurrent protection is utilized as the startup criterion. The additional criteria are added to the further distinction between internal faults and external faults to prevent protection malfunction. The loop DC-distribution network protection scheme simulation based-on real-time digital simulator (RTDS) has verified the feasibility and effectiveness of the proposed scheme.