Full current harmonic detection method based on sinusoidal amplitude integrator

摘要

There are many methods for detecting harmonic current in grid, which have different characteristics. I_p-i_q detection method based on instantaneous reactive power theory is complex and various link, when the grid voltage is unbalanced, the grid synchronization signal error will appear, and low-pass filter (LPF) in harmonic detection link brings influence about rapidity. In order to detect the harmonic current accurately and rapidly, realize the compensation of full current harmonics, this article presents a harmonic detection method based on sinusoidal amplitude integrators (SAI), which is not only suitable for balanced grid, but also can detect the harmonic current accurately when the grid is unbalanced. The harmonic current detection method based on sinusoidal amplitude integrator is used to extract the positive sequence fundamental current based on the positive sequence SAI structure. The simulation of the proposed method is carried out under the condition of balanced and unbalanced grid, which verifies the feasibility and effectiveness of the proposed method.