谐振型限流器过电压保护电路拓扑设计与优化

谐振型限流器的电容器因故障电流引起过电压，传统过电压保护技术不适合限流器的系统工况。该文提出了新型过电压保护电路方案。该电路采用避雷器、晶闸管阀、间隙和快速开关等保护器件，保护器件特性不同，需与之相适应的阻尼回路也不同，其组合可构成多种拓扑结构，文中建立了3种拓扑类型数学模型，分析了阻尼电路的电流应力变化情况，从中优化了拓扑结构。阻尼参数影响电流陡度和振荡时间，通过仿真计算优化了阻尼参数。故障电流和电容器放电电流叠加使晶闸管阀体承受巨大的电流应力，建立晶闸管阀热阻抗模型，分析了暂态温升变化。仿真试验结果证明设计原理的正确性和可行性。

Design and Analysis on Overvoltage Protection Circuit Topology of Resonance Fault Current Limiter

The resonance fault current limiter (RFCL) is a practical way to solve the problem of the bulk fault current on the EHV. The capacitor will endure overvoltage for the fault current. Traditional ways of overvoltage protection are not meeting with the RFCL needs. The new type of overvoltage protection circuit is introduced. The protective equipment consisted with thyristor, gap and bypass breaker. The characters of equipment are not the same so that they have different damping circuit topology. Mathematical model of topology circuit is built to analyze the current strength. Thus the structure is optimized. Damping parameters also affect the current gradient and surge time. They are ranged in numerical value through lots of simulation. Fault current and discharging current of capacitor would give more current strength to the thyristor. The transient temperature changed by the current strength is analyzed through Cauer model. Simulation proved the theory correct and practical.