Integrator is essential in pulse current measurement system based on Rogowski coil. The analog integrator can performance a lower accumulated error for continuous signals inputting. But the component of the analog integrated circuit is non-ideal and easy to be interfered by electromagnetic pulses. However, the digital integrator can be more accuracy and more stable because the integration progress is without interference. With the developing of high-speed digital circuit,the digital integrator is possible for pulse current measurement. In order to improve the accuracy and simplify the circuit, this paper proposed an improved digital integrator. The paper compared several common digital integrators by Matlab and made it practical by adding a Butterworth band-pass filter and a bias compensation factor. The result of discharging experiment testifies the SNR of the improved digital integrator is much higher than analog ones and the accumulated error is acceptable.%在基于罗氏线圈电流互感器的脉冲电流测量系统中,需要积分器来还原被测电流波形,传统的模拟积分器输入连续信号,累计误差小,但积分过程暴露在电磁噪声干扰中,影响测量精度.而数字积分器电路简单,积分过程不受噪声干扰,可以有效提高信噪比.通过Matlab仿真对比分析了普通数字积分器与模拟积分器的频域特性,选定了复化辛普森公式为最佳数字积分原型.以PFN放电脉冲电流的测量为背景进行研究,针对数字积分器的实用化提出了改进方案,加入了带通滤波器和零点补偿,解决了零点漂移、积分饱和等问题,并在基于STM32的数据采集系统中得到了理想的试验结果.
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