交流滤波器内部谐波电流分布计算及其过负荷逻辑优化

Distribution calculation of harmonic current in AC filter and its overload logic optimization

针对近期频繁发生的交流滤波器过负荷保护跳闸问题,首先建立了双调谐和三调谐2种交流滤波器阻抗计算模型,并利用PSCAD/EMTDC就不同谐波电流源情况下2种类型交流滤波器的内部电阻、电抗的谐波电流分布进行了仿真计算与分析。同时为保障交流滤波器电阻器、电抗器设备的安全运行,真实反映其过负荷能力,提出了在保留原先的定时限过负荷保护的基础上,增设符合基于IEC60255-8的热曲线模型的反时限保护策略,提高了交流滤波器安全运行能力。

The paper establishes a impedance calculation model of double tuned and three tuned AC filter on the frequent trip problem of AC filter overload protection,The internal resistance and reactance harmonic current distribution of the two types filter under different harmonic current sources are simulated and analyzed using PSCAD/EMTDC.A time-inverse protection strategy which accords with the IEC60255-8 based thermal curve model is proposed here to ensure the safe operation of the AC filter resistor and reactor and truly reflect the overload capacity of the equipment,which preserves the original time limited overload protection.That makes the safe operation ability of AC filters enormously improved.