Research of the Overvoltage at Switching off the Unloaded 500 kV Line Based on JMarti Model

This paper analyzes the mechanism of the overvoltage at switching off the unload 500 kV line and establishes the JMarti model of overvoltage simulation.The model possesses reliable accuracy and stability of numerical calculation.Applying Electro-Magnetic Transient Program to simulate switching overvoltage of practical example.The calculation of switching overvoltage is important to rational power equipment design and practical system security operation.