加Blackman-Harris窗插值算法仿真介损角测量

为了更好地将加布莱克曼-哈里斯(Blackman-Harris)窗插值谐波分析法用于介损角测量,仿真分析了该算法及其在信号频率、3次谐波、直流分量、采样频率、A/D量化位数、采样时间长度、介损角真实值、白噪声及脉冲噪声变化时计算所得介损角误差的变化。仿真结果表明,频率波动时算法误差很小且稳定;算法随3次谐波分量的增加误差有很微小的增加;算法随直流分量的增加变化不显著;算法随A/D量化位数的增加误差减少,≥10位的量化位数能满足精度要求;随采样频率的增加误差稍有下降,但趋势不明显;随采样长度增加误差减少,0.1s的采样时间长度足够;介损角误差与真实值的关系不大;随白噪声和脉冲噪声含量的减少误差减少,对白噪声和脉冲噪声信噪比约80 dB能满足要求。

Simulation Analysis of Dielectric Loss Angle Measured by the Blackman-Harris Window Interpolation Algorithm

The error of dielectric loss angle measurement caused by asynchronous sampling can be alleviated by the Blackman-Harris windowed interpolated harmonic analysis algorithm.Due to its high accuracy,the algorithm is a very practical for dielectric loss angle measurement.For more effectively applying the algorithm to dielectric loss angle measurement,the influence of change of some kinds of parameters on error of dielectric loss angle is simulated and analyzed,the parameters include signal frequency,third-harmonic component,direct current component,sampling frequency,A/D quantization bits,sampling time length,real value of dielectric loss angle,white noise and impulse noise.The results indicate that the error of the algorithm is small and very steady when the signal frequency fluctuates.It is found that the error of the algorithm has very small increase with the increase of third-harmonic component,it changes slowly with the increase of direct current component,and it decreases with the increase of A/D quantization bits number,no less than 10 bit quantization bits number is enough for A/D.The error of the algorithm decreases slowly with the increase of sampling frequency;and it decreases with the increase of sampling time,0.1s is long enough for sampling time.The error of the algorithm is little related to the real value of dielectric loss angle,and it decreases with the increase of SNR if white noise or impulse noise exists,if the SNR approaches to 80 dB,the accuracy can satisfy the requirements.