动态条件下同步相量测量装置的数字滤波器及计算优化

摘要

随着广域测量系统对同步相量测量装置动态性能越来越严格的要求,数字滤波器在装置中的应用趋于复杂.为了提高精度,往往要采用多个滤波器互相配合完成计算.针对智能变电站的同步相量测量装置给出了详细的滤波器设计方案.有限冲激响应(FIR)滤波器级联离散傅里叶变换(DFT)会带来非常大的运算量,给嵌入式装置带来计算压力,为此推导出了FIR滤波器级联DFT后的滤波系数公式.利用该公式离线计算出滤波器级联后的滤波系数,能大幅减少计算量,解决滤波器级联带来的运算量大的问题.理论分析和实际测试表明,采用所述方案后,测量精度能够满足相关标准的要求,且大幅减轻了装置的计算负担.%With the increasingly stringent requirement of wide area measurement system for the dynamic performance of synchronous phasor measuring unit,the application of digital filter in the device tends to become complicated.In order to improve the accuracy,multiple filters often have to cooperate with each other to complete the calculation.This paper gives a detailed filter design of synchronous phasor measuring unit for intelligent substation.Finite impulse response (FIR) filter cascade discrete Fourier transform (DFT) will bring about a very large amount of computation pressure on the embedded device.This paper deduces the formula of filter coefficients after FIR cascade DFT.These coefficients calculated by offline formula can significantly reduce the calculation workload and solve the computation problem caused by the filter cascade.Theoretical analysis and practical test show that measuring accuracy is up to requirement of the relevant standards after adopting the above scheme.