Scholarship support for overseas students' scientific and technological activities (C2015003043); Hebei “Giant Plan” wind-solar complementary hydrogen production and comprehensive utilization innovation team project; wind power/photovoltaic hydrogen synthesis and comprehensive utilization engineering laboratory project in Hebei Province; Hebei Provincial Science and Technology Department support plan focus Project (19214501D); Key Project of Foreign Experts Administration of Hebei Science and Technology Department (2019YX005A);
The ripple component of the DC bus voltage will affect the power supply quality of the entire DC microgrid and the safety of equipment operation. Therefore, a new DC active power filter (DC-APF) control strategy is proposed to suppress the DC bus voltage ripple. Aiming at the problems of delay in the traditional DC bus voltage ripple detection algorithm and the slow response speed and poor dynamic performance of the traditional PI compensation control current algorithm, the ripple detection method and suppression scheme are optimized based on the analysis of various work modes of DC-APF. In terms of detection, a DC bus voltage ripple detection method based on wavelet transform Mallat algorithm is proposed, which can realize rapid detection of ripple. On the basis of traditional and fuzzy PI control, an improved fuzzy adaptive PI control is proposed to realize the tracking control method of compensation current to improve dynamic performance of the system. A DC micro-grid system model with DC-APF is built in MATLAB/Simulink, and the simulation results show that compared with the traditional DC-APF control strategy, the new type DC-APF control strategy can achieve rapid detection of DC bus voltage ripple and has good ripple compensation effect. The research results can provide new ideas for ripple detection and suppression in DC microgrid.