电容式电压互感器动模模型设计及测试

Dynamic Model Design of Capacitor Voltage Transformer for Relay Protection Test

针对电容式电压互感器(CVT)对电力系统安全稳定产生的不利影响,基于实际的CVT等值模型,将中间变压器的激磁支路开路后并联至等值模型的入口来调整CVT等值模型,在此基础上提出通过改造传统电磁式电压互感器(PT)二次侧来建立CVT动模模型的方案,根据CVT中间变压器励磁阻抗与动模实验室中PT激磁阻抗的相互关系,计算CVT动模模型参数,从而完成CVT动模模型的建立。将动模试验结果与PSCAD仿真结果进行对比,验证了该CVT动模模型能够准确地模拟实际CVT的暂态特性。

Capacitor voltage transformer（CVT）has adverse impact on security and stability of power systems.The dynamic simulation experimental model of CVT is developed based on its equivalent model.The magnetizing impedance of intermediate transformer in the equivalent model of actual CVT has been moved the intermediate transformer into the entrance of the equivalent model as a convenience.According to the transformed equivalent model of CVT,the dynamic modeling scheme of CVT is proposed by reforming at the secondary side of traditional PT.According to the relationship between the magnetizing impedance of intermediate transformer and PT,the parameters of CVT dynamic model is calculated and the physical modeling of CVT is completed.By comparing the results of dynamic simulation and PSCAD simulation,it demonstrates that the CVT dynamic model can accurately simulate the transient characteristics of the actual CVT.