LAUSR

The instantaneous power for a three-phase rectifier can be calculated directly in the orthogonal coordinate system via coordinate transformation. However, it is difficult to calculate the instantaneous power directly for a single-phase rectifier due to the lack of another phase. Therefore, an orthogonal signal generator (OSG) is required to create an orthogonal coordinate system. Currently, conventional OSG algorithms suffer from long response time. To remedy this problem, in this paper, an arbitrary phase-delay OSG algorithm is developed and applied to the direct power control (DPC) system in the single-phase rectifiers. First, the instantaneous power theory and DPC are presented. Then, the principle of the arbitrary phase-delay OSG method is introduced and the anti-interference ability of the proposed method is analyzed. Through the dynamic response analysis, the developed algorithm brings faster response, easier implementation, and less computational burden compared with other common OSG algorithms. Finally, the validity and advancement of the proposed algorithm are verified by simulations and hardware-in-the-loop experimental tests. A comparison with conventional OSG algorithms also proves the advantages of the developed method.