7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

187 / 2024-04-15 20:06:48

Analysis of Square Wave Response of Equivalent Network for Vacuum Interrupter

HV-Vacuum Interrupter,Equivalent Network,Square Wave Response,Wave Process,Suspension Potential Shield

    Vacuum interrupter is the core component of the new generation of environmentally friendly vacuum switches. Optimizing the design structure of the electromagnetic field in the vacuum interrupter is of utmost importance. Among them, the parameters of the suspended shielding cover inside the vacuum interrupter directly influence the potential distribution along the surface of the interrupter, making it one of the key focuses in electric field design. As the voltage level increases, the height of the high voltage vacuum interrupter gradually increases. The equivalent wavelength of pulse signals such as lightning impulse voltage and transient recovery voltage (TRV) with fast rising edge is similar to the size of the vacuum interrupter. Therefore, when analyzing the potential distribution of the vacuum interrupter, it is necessary to consider the wave process of the pulse signal propagating inside it. This paper takes the 252 kV vacuum interrupter as an example, analyzes its stray capacitance distribution under the electrostatic field by the capacitance matrix, and calculates the stray inductance of the conducting rod. On this basis, this paper establishes a distribution parameter model for a 252 kV vacuum interrupter, and analyzes the voltage response of each node under pulse square waves and the localized pulse overvoltage caused by wave processes. Simultaneously, we focus on the dynamic potential distribution of free charges, conduction currents, and the casing inside the vacuum arc quenching chamber. The results show that the pulsed square wave exhibits an obvious propagation process on the vacuum interrupter, and there are differences in the starting moments of changes in the suspension potential at different locations. Therefore, according to the influence of the propagation process of the pulse square wave inside the vacuum interrupter, correcting the geometric and electrical parameters of each charged body can support the design of the suspension potential shield inside the 252kV vacuum interrupter to achieve the purpose of dividing the TRV and sharing the electric field stress.