高压并联电抗器匝间保护防饱和误动方法研究

Maloperation Prevention for Inter-turn Protection of High Voltage Shunt Reactor

高压并联电抗器(high voltage shunt reactor,HVSR)易于在端电压突增的情况下饱和,电气特征上高抗饱和与匝间短路之间较为模糊,传统的基于零序电气量的匝间保护存在误动风险。提出一种新型高抗饱和防误动方法,针对高抗饱和误动问题,构建了基于谐波分量及直流分量的闭锁判据,防止匝间保护在高抗饱和时误动作;同时,为避免所提出的闭锁判据导致匝间保护灵敏度下降,利用高抗在故障及饱和条件下的阻抗特性差异,构建了基于绕组计算电感波动的开放判据,实现了对高抗饱和匝间短路的准确识别,且在高抗匝间短路故障与饱和同时发生时也能可靠开放保护动作。RTDS仿真结果验证了该方法的有效性。

It is easy for high voltage shunt reactor(HVSR)to be saturated when its terminal voltage suddenly increases,and the differences on their electrical characteristics between the HVSR inrush current and the inter-turn fault are fuzzy.The traditional inter-turn protection based on zero sequence electrical quantity has a risk of maloperation.Therefore,this paper proposes a new method to prevent the inrush current from maloperation.Aiming at the problem of high anti-saturation maloperation,a blocking criterion based on the content of harmonic component is firstly constructed to prevent the maloperation of HVSR inter-turn protection.In order to avoid the problem of misjudging inter-turn fault as saturation,an open criterion based on the calculation of inductance fluctuation of winding is then constructed by using the different impedance characteristics of HVSR under the fault and the saturation conditions,realizing the accurate identification of saturation and fault,and the reliable open-up protection when an inter-turn fault and a saturation occur at the same time.The simulation results of RTDS verify the effectiveness of this method.