基于对角隐式Runge-Kutta法的新型数字积分器研究

数字积分器是基于空心线圈的电子式电流互感器的重要环节之一。对此文中基于对角隐式龙格库塔法提出了一种新的拓展梯形数字积分算法。为提高新型数字积分算法的积分精度,采用复合积分并推导出了不同采样频率下的通用新型数字积分器的传递函数。由于新型数字积分器的传递函数中含有分数延迟项,因此采用FIR和IIR两种滤波算法对其进行仿真分析。MATLAB仿真结果表明,新型数字积分器在低频段的性能要优于梯形数字积分器,可为基于Rogowski线圈的电子式电流互感器的积分环节提供一种全新的设计方法。

New digital integrator schemes for electronic current transformer based on diagonally implicit Runge-Kutta methods

The digital integrator is one of the important aspects of an electronic current transformer based on an air coil. In this paper, a new extended trapezoidal digital integration algorithm is proposed based on the diagonally implicit Runge-Kutta method. In order to improve the integration accuracy of the new digital integration algorithm, composite integration is used to derive the transfer function of a universal new-type digital integrator at different sample frequencies. Since the transfer function of the new digital integrator contains a fractional delay term, it is simulated using FIR and IIR filter algorithms. The simulation results by Matlab show that the performance of the new digital integrator is better than that of the trapezoidal digital integrator in the low frequency range, which can provide a new design method for the integral part of the electronic current transformer based on Rogowski coil.