为了进行冲击电压下局部放电现象的研究,研制了一款专门用于局部放电脉冲测量的高频电流传感器。在分析了该传感器的工作原理及其传递特性后研究了线圈匝数、积分电阻和杂散电容对其频率特性的影响;利用方波电压源,校准了研制的电流传感器;利用函数发生器测试了不同频率下的传感器的实际动态响应。结果表明,传感器带宽达800kHz~105MHz,灵敏度为2.4V/A,通频带内具有良好线性度和较小相移。应用此传感器对针板电极试验模型在冲击电压作用下的局部放电信号进行测量,获得了与理论分析一致试验结果,为进一步研究冲击电压下局部放电特性和机理提供了有效的测量手段。
In order to study partial discharge pulses under impulse voltage effectively, a high-frequency current transducer for measurement of PD is developed. According to the equivalent circuit model, its principle and transmission characteristics are analyzed, and the effects of coil turns,integral resistance and stray capacitance on frequency properties are studied. Moreover, calibration and analysis of the actual dynamic response are performed by adopting function generator and square-wave source. PerFormance tests show that it has good linearity and small phase shift with a wide bandwidth of 800 kHz-105 MHz and high sensitivity of 2.4 V/A. Based on the transducer, measurements of PD of needle-plate model under impulse voltage is identical to the results of theory analysis. It could be effective approach not only for deep study on PD character, but atso to explore the mechanism under impulse voltage.