基于多层PCB罗氏线圈的精密冲击电流测量装置

为准确评估防雷设备性能,冲击电流测量装置的测量精度和响应特性至关重要,因此文中提出了高频性能好、抗干扰能力强、灵敏度足够大的多层印刷电路板(PCB)罗氏线圈设计方案。文中分析了雷电流波形的频率范围以及罗氏线圈的传变特性;依据罗氏线圈尺寸、匝数与线圈频率特性之间的关系曲线,确定了线圈的结构尺寸;设计了新型屏蔽和信号输出方式,增强抗干扰能力。通过增加线圈厚度和串联线圈的方法,增大输出电压灵敏度。根据标准要求,进行测量装置的动态特性、标准雷电流测量误差以及线性度试验研究。试验中测量装置响应时间小于90 ns,相对过冲小于10%;与标准Pearson线圈比对,峰值误差小于0.2%,时间参数测量误差小于0.3%;5~40 kA电流范围内,测量装置线性度约为0.3%。试验结果表明研制的冲击电流测量装置具有良好的高频电流信号测量能力。

Precision impulse current measuring device based on multi-layer PCB Rogowski coil

In order to accurately evaluate the performance of lightning protection equipment, the measurement level and response characteristics of transient current measurement sensor are very important. This paper presents a design scheme of multi-layer PCB Rogowski coil with good high frequency performance, strong anti-interference ability and suitable sensitivity. The frequency range of lightning current waveform and the transmission characteristics of Rogowski coil are analyzed. According to the relationship curve between the size of Rogowski coil, turns number, and the frequency characteristics of coil, the structure size of coil is determined. A new shielding and signal output mode is designed to enhance the anti-interference ability. The sensitivity of output voltage is increased by increasing coil thickness and connecting two coils in series. According to the standard requirements, the dynamic characteristics of the measuring device, the measurement error of standard lightning current and the linearity test are carried out. The step response test of the measuring device shows that the response time is less than 90 ns and the relative overshoot is less than 10%. Compared with the standard Pearson coil, the peak error is less than 0.2%, the time parameter measurement error is less than 0.3%. The linearity of the measuring device is about 0.3% with current range from 5kA to 40kA. The test results show that the impulse current measuring system can measure high frequency current signal.