Coordinated Second-Order Voltage Harmonic Mitigation in Hybrid Microgrids

This article introduces a compensation methodology that enables the coordination of multiple dc–dc converters to mitigate the second-order voltage harmonic component in hybrid microgrids. The proposed methodology utilizes metaheuristic algorithms to prohibit circulating currents and share harmonic currents among the compensating circuits. The proposed method can be easily implemented by any dc–dc converter while its efficacy is independent of the feeders’ impedances and the physical location of the compensating equipment. The elimination of circulating currents and the capability to share the total compensation current between the compensating circuits are not affected by the line impedances. In addition, the implementation of the proposed scheme does not require any expensive real-time communication. The mathematical analysis of hybrid microgrids seen from the perspective of harmonic compensation by coordinating multiple dc–dc converters is also presented, being a useful tool to design compensation methods. In addition, a qualitative and a quantitative comparison of the proposed methodology with prior-art methods in the literature are presented to further demonstrate the performance of the proposed solution. Finally, simulations and experimental tests verify the effectiveness of the proposed methodology.