Abstract:
As high proportion of new energy and a large number of uncertain loads are connected to DC microgrid through DC converters, the control strategy of DC/DC converters will play an important role in maintaining the stability of DC bus voltage, whereas the nonlinear uncertain dynamic characteristics of source loads make it difficult to accurately model the converters. Consequently, the ultra-local model control strategy based on sliding mode observers for dual active full-bridge converters is proposed, a DC/DC converter ultra-local model is constructed, and a sliding mode observer is introduced to accurately estimate the unknown terms in the ultra-local model to improve the control effect. Moreover, the Lyapunov stability theory verifies the stability of the control method. It is verified by the built simulation and experimental platform that the proposed control strategy can enable the DC bus voltage to possess good stability and robustness under various disturbances.