A Novel Decentralized Droop Control Scheme for Multiparalleled APFs With Grid Current Detected

With the development of renewable energy generation, a single active power filter (APF) can hardly satisfy the requirements for harmonic compensation in high-power applications. Consequently, APFs are frequently connected in parallel to boost the capacity. And a central controller or a communication line is employed to allocate the compensation capacity. However, the intercommunication among APFs not only diminishes the reliability of the system, but also deteriorates the dynamic response. Additionally, hardware modifications must be applied to the original single APFs. Therefore, this article proposes a novel decentralized droop control scheme for multiparalleled APFs. With grid current detected, the proposed scheme enables the APFs to automatically allocate the compensation current. In comparison with prior research, both harmonic filtering and current sharing exhibit substantial enhancements, while dynamic response is maintained. Besides, the proposed scheme is more suitable for N multiparalleled APFs with lower steady error and better reliability. The detailed operating principle, parameter tuning, and performance analysis are presented. Finally, the proposed scheme is verified by simulations and experiments under various operating conditions.