【摘要】 采用避雷器可以限制雷电过电压的幅值,但不能抑制陡度,变压器因雷电过电压造成的事故还时有发生。提出将高频磁环并联阻尼电阻后串接在线路的适当位置来抑制变电站变压器雷电过电压的方法。通过振荡回路的试验和仿真建立了高频磁环的EMTP仿真计算模型。针对某实际220 kV变电站的仿真计算结果表明,通过选择适当的磁环材料和优化磁环的形状和尺寸,采用该方法可有效降低变压器雷电过电压的幅值和陡度,可作为避雷器保护的补充和完善措施。更多还原

【Abstract】 In view of the fact the arrester can only suppress the magnitude,but not the steepness,of a lightning overvoltage,so the failures of power transformers due to lightning overvoltage happen occasionally.The authors propose an approach to suppress lightning overvoltage of transformers located in substations by means of high-frequency magneitc rings,which connect in parallel with damping resistor,in series with transmission line in appropriate position.Through the test and simulation of oscillation circuit,an EMTP model to simulate and calculate high-frequency magnetic rings is built.Simulation and calculation results of a certain actual 220 kV substation show that by means of choosing proper material as well as proper shape and size for magnetic rings,the proposed approach can effectively suppress the amplitude of lightning overvoltge and alleviate its steepness,thus it can be used as a supplementary measure to the arresters.更多还原