Design and Simulation of Improved Harmonic Current Detection Method

In order to increase the influence of harmonic current of power grids, accurately detecting the harmonic current is the key technology of reactive power compensation and harmonic current detection method. Traditional harmonic current detection method calculating process is complex and the voltage phase can not be obtained accurately under the condition of voltage distortion. Using the double second-order generalized integrator of the basic principle of phase-locked loop analysis and modeling instead of the traditional phase-locked loop. An improved harmonic current detection method is proposed, combined with the harmonic detection method for unit power factor. In the case of voltage distortion, it can still quickly and accurately achieve the detection of the amount of compensation. This paper uses Matlab to simulate the detection method based on UPF and the improved method with DSOGI-SPLL in case of grid voltage distortion. In the end, the results show that the UPF traditional detection method under the environment of voltage distortion aberration rate was 13.81%, and the improved UPF detection method of aberration rate was 3.12%. The latter, rather than the former, can accurately detect the harmonic and reactive component of load current affected by the voltage distortion, which is smaller.