关键词: 电气工程, 可控电抗器, 超高压输电线路, 工频过电压, 操作过电压, 潜供电流, 电磁暂态仿真程序

Abstract: In order to solve the problem that fixed shunt reactors applied in extrahigh voltage transmission lines significantly restrict transmitted power and result in excessively low voltage, a scheme of using magnetically controlled reactor (MCR) was put forward. First, MCR structure and essential working principle were introduced, and its model was build based on small slope magnetization curve The analysis of the characteristics of MCR focusing on harmonic distribution, voltagecurrent property, control law and response time were conducted. Theoretical formulae were given for the selection of neutral grounding of MCR. By using Electromagnetic Transient Program (EMTP), simulation model of 500kV transmission line from Sanyou to Jiangling was built to study control effects on frequency overvoltage, switching overvoltage suppression and secondary arc current limitation. Simulation results indicate that MCR can smooth voltage and regulate reactive power, suppress power frequency and switching overvoltage, limit secondary arc current during single phase fault reclosing, which show the feasibility and effectiveness of MCR applications in extrahigh voltage transmission line.

Key words: electrical engineering, magnetically controlled reactor (MCR), extrahigh voltage (EHV) transmission line, frequency overvoltage, switching overvoltage, secondary arc current, electromagnetic transient program (EMTP)