A new approach for distance protection using compensated voltage distribution under distributed parameter model

The traditional distance protections mainly use lumped parameter model and have bad performance under high resistance earth fault conditions. The paper presents a new distance protection for long transmission line using voltage distribution. The new method distinguishes the internal fault from the external fault by identifying the terminal voltage distribution trend based on the distributed parameter model. The effectiveness of new principle is analyzed in detail and theoretical error formula is deduced. The proposed method adopts distributed parameters model and has characteristics of low computational complexity and high capacity of earth-fault resistance. The feasibility has been verified by digital simulation and in-field record data simulation of distributed parameter line model.