This paper advises to establish a mathematical model which not adding to the power-factor compensation for the Gas Discharge Lamp and series voltage resonance for the Electronic Ballast of the fluorescent lamp.

By analyzing the voltage,current,voltage resonance and current resonance principle in the resonant earthed system,this paper presents the equivalent analysis models of the resonant earthed system.

With theoretical analysis and practical calculation it is proved that the overvoltage phenomenon which appeared in the startup and adjustment process of Dongming switching station is a serial voltage resonance caused by the parameter mismatch.

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.

Study of Piezoelectric Resonator Type Force Sensor Respond Time;