A Novel Protection Principle of DC System Based on Voltage Elasticity Coefficient

The high resistance fault reduces the sensitivity and reliability of the main protection of the DC line, and seriously affects the safety of the system. Accordingly, a protection principle based on the voltage elasticity coefficient of the current limiting reactor (CLR) is established. First, the fault characteristics of the (CLR) voltage of the flexible DC system are analyzed. Then, a concept of elastic coefficient is given to express voltage, and a single-ended protection principle is proposed accordingly. Finally, a typical flexible DC system model is used to demonstrate the reliability and performance of the scheme. Numerous simulation results demonstrate the advantages of the proposed principle.