Study on Submarine Cable Opening Overvoltage Modeling and Its Suppression Technology

Capacitive components of the power system are energy storage components, when the operation or failure to change its working state, there will be a transition process. During the transition, since the power supply continues to supply energy, and the magnetic energy stored in the inductor translates into a capacitance in the form of electrostatic field energy stored in the system at some point, an overvoltage several times greater than the supply voltage, this is the operation over voltage. In the transmission line, the common overvoltage operation has cut off the no-load line overvoltage and closing no-load line overvoltage. Due to the obvious effect of capacitance of submarine cable used by offshore wind farms and the reactive voltage distribution characteristics of offshore submarine cables connected to the grid with onshore wind farms, there are significant differences in fault characteristics and overvoltage problems are prone to occur. In particular, the overvoltage caused by the switch-off of the circuit breaker caused by the system state transition is especially obvious. The overvoltage of the sub-gate is especially obvious. It is urgent to analyze the transmission line overvoltage of large-scale offshore submarine wind farms and explain the generating mechanism of overvoltage and its restraining measures. It provides a theoretical basis for the study of engineering overvoltage suppression and engineering calculation and analysis.