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.