Research on Over-voltage Protection Strategy of Series Compensation Device

The series compensation device can use the series capacitance resistance to compensate for the partial inductive resistance of the transmission line, which plays an important role in effectively improving the line transmission capacity, increasing the safety and stability level of the system and suppressing the system oscillation. However, when the short circuit fault occurs in the system, the short circuit current of the system will cause large overvoltage on both sides of the capacitor, and then damage the equipment, and directly affects the safe operation of the string complement device, so it is necessary to study the overvoltage protection of the string supplement device. This paper introduces the principle of MOV overvoltage protection, and builds a 500kV transmission grid model with fixed string supplement device by using PSCAD simulation software. On this basis, the MOV overvoltage protection characteristics of series compensation device are analyzed, and finally the influence of different fault types and fault position on MOV energy demand is explored, which provides a reference for the overvoltage protection design of series compensation device.