An Improved Three-Phase Four-Wire Harmonic Detection Algorithm Based on Multi-Synchronous Rotating Frame Transformation

Compensation of reactive current, harmonic current and unbalanced current are important to improve the quality of electric energy, the key point of which relies on a fast and accurate harmonic detection algorithm. An improved harmonic detection algorithm based on multi-synchronous rotating frame transformation in three-phase four-wire system in distribution network is designed in this paper. Compared to traditional approaches, the improved algorithm keeps high accuracy and dynamic response for selective harmonic detection by using PI controllers with feedback. And the steady-state and dynamic performance of harmonic detection algorithm are analyzed by the frequency domain methods. Finally, the effectiveness of the algorithm is verified by simulation.