A Novel Nonlinear and Adaptive Control of Grid Connected Inverters

In this study, a new nonlinear and adaptive state feedback controller is proposed for the control of grid connected inverters (GCIs). All the other parameters apart from direct current (DC) bus capacitor are considered uncertain in the design of proposed controller, without disadvantages of singularity and over-parametrization. Three-phase source currents, DC bus voltage and load current are supposed to be available for feedback in the closed loop control system. In this respect, the whole control loop, consisting of DC bus voltage and d-q axis current loops, is closed. It is important to highlight that closed loop DC voltage control cannot be achieved by most of nonlinear controllers proposed in literature. In the sense of Lyapunov stability theory, overall control system has the global asymptotic stability. Experimental results demonstrate that the proposed controller guarantees to asymptotically drive tracking errors to zero despite all parameter and external disturbance uncertainties. Results also verify that the proposed controller shows high performance and feasibility.