In the light of the analysis of the resonant overvoltage ,the causes of resonant overvoltage are found out ,and the methods to solve the problems are put forward,to ensure the safety and reliable operation of the power System.

The RTDS was used to analyze and calculate the resonant overvoltage occurred during start-up debugging of 500 kV Ganshan-shuangsi double-circuit lines on the same tower,and the hidden troubles in various operational modes are studied.

With the understanding of the generation of the resonant overvoltage and ferromagnetic resonance overvoltage limit,lightning arrester and the HXB arc-resonance extinguishing overvoltage protection installment are proposed to use.

As for the 1000kV AC pilot project in China, it is possible to appear resonance overvoltage with higher amplitude caused by energizing no-load transformers.

This paper, from the technological perspective, analyzes the causes of displacement over-voltage of neutral points, break-line over-voltage, iron magnetic resonant over-voltage & arc over-voltage, and proposes more than two technical solutions to these problems.

Based on the parameters of the circuit composed of single-phase, three-phase inductors and capacitors, the resonant conditions when both serial and shunt constructed were analyzed, and the reason why the resonant over-voltage occurred in 6 kV system was proposed, along with its prevention and dealing methods.