Novel method for restraining 35 kV shunt reactor switching overvoltage – phase controlled breaker

Abstract

Phenomena such as current chopping, arc reignition and equivalent current chopping might appear when cutting off shunt reactor. Overvoltage caused by switching will lead to interphase fault in related equipment and inter-turn insulation damage in the shunt reactor, which will threaten the safety of electrical equipment. In recent years, equipment breakdowns caused by 35 kV shunt reactor switching overvoltage in 220 kV substation occur frequently in China, endangering the safe and stable the power grid. In this study, the mechanism, perniciousness and suppression of shunt reactor switching overvoltage are systematically analysed. The strategy of phase controlled breaker is put forward, and the overvoltage measurement and power systems computer aided design (PSCAD) simulation analysis are carried out. The work and conclusion of this study provide the solutions and engineering experience for the switching overvoltage suppression of 35 kV shunt reactor.

Keywords

• fault diagnosis
• reactors (electric)
• circuit breakers
• power grids
• overvoltage protection
• substation protection
• equivalent current chopping
• inter-turn insulation damage
• phase controlled breaker
• overvoltage measurement
• switching overvoltage suppression
• shunt reactor switching overvoltage
• PSCAD simulation analysis
• arc reignition
• interphase fault
• equipment breakdowns
• power grid
• voltage 35.0 kV
• voltage 220.0 kV