Composite finite-time output voltage tracking control of energy storage inverters with mismatched multiple disturbances

This paper investigates the finite-time output voltage tracking control problem of energy storage inverters. Multiple load conditions are simultaneously considered. To complete the tracking control task and enhance the power quality under different loads, a composite control scheme, which contains two parts, is proposed. In the first part, two finite-time disturbance observers are established to estimate the mismatched multiple disturbances originating from load variations. In the second part, new integral-type sliding-mode surfaces embedding disturbance estimates and dq$$ dq $$-axis couplings are designed, which not only feedforward compensate for the disturbances but also achieve decoupling. Based on the sliding-mode surfaces, a composite controller is constructed. Compared with the existing results, the proposed controller is continuous and significantly reduces chattering. Moreover, with the novel decoupling strategy, the dq$$ dq $$-axis coupling problem is solved precisely without generalizing the couplings as disturbances, which simplifies the observation task and further accelerates system convergence. Rigorous stability analysis is conducted to demonstrate the accomplishment of the finite-time tracking task. Simulations and experiments are presented to validate the effects of the proposed control scheme.