电子式电流互感器电磁抗干扰仿真与测试

Simulation and Test of Electromagnetic Interference with Electronic Current Transformer

为提高电子式电流互感器电磁防护性能,对其进行等效电路建模仿真与试验测试。在隔离开关分合容性小电流试验状态下,搭建隔离开关分合模型,得出操作过电压和过电流的电流仿真波形,以此暂态电流信号为激励源,对罗氏线圈建立等效电路模型,仿真隔离开关分合操作时的罗氏线圈输出为高频信号,输出电压峰值高达680 V,导致采集单元中A/D转换器无法正常工作。最后针对罗氏线圈输出信号的特点,提出TVS管与RC低通滤波器相结合的电磁抗干扰措施,并对抗干扰措施进行建模仿真,结果表明瞬态电压峰值可降到0.6 V以下。通过对电子式电流互感器进行隔离开关分合容性小电流试验测试,测试结果证明了上述的建模方法及抗干扰措施的有效可靠性。

In order to improve the performances of electromagnetic protection of electronic transformers, we tried to simulate the equivalent circuit and test the devices. We established an electronic transformer simulation model with isolator switch under small capacitive current test status. Using this model, we got the operating over-voltage and over-current current simulation waveforms. Moreover, using the transient current signal as an excitation source, we established an equivalent circuit model according to the electrical parameters of the Rogowski coil. The Rogowski coil output was high-frequency signal with the output voltage spikes up to 680 V, which caused the A/D converter in the acquisition unit unable to work properly. According to the characteristics of the output signal of the Kogowski coil, we proposed electromagnetic interference measures that TVS tube and RC low-pass filter should be combined. The measures simulation modeling results show that the transient voltage spikes can be reduced to below 0.6 V. Finally, we have tested the isolation switch of electronic transformer under small capacitive current division experiment, the test results have verified the reliability of the above efficient modeling methods and anti-jamming measures.