Research and Comparison on Phase Compensation Schemes for Electronic Transformer

The phase error of electronic transformer is an important factor which will affect the measurement accuracy.However,the phase error can be modified through a proper phase compensation scheme.The principle of the electronic transformer has been given out and the causes of phase error have been analyzed.The phase compensation schemes,including all-pass filter,phase-shifted algorithm of short data window,and phase-shifted algorithm of Fourier,have been introduced.The influence of the harmonic on above schemes has also been researched.On this basis,an improved schemes of phase compensation is presented,,namely sampling points removed and the linear phase of all-pass filter scheme.The experimental results show that the phase error of transformer can meet the class 0.2 accuracy requirements so as to verify the feasibility.