Decoupled Active and Reactive Power Control of a Grid-Connected Inverter-Based DG Using Adaptive Input–Output Feedback Linearization

This paper presents a new direct active and reactive power control for DC–AC converters connected to three-phase network through a filter and lossless/lossy line. The control is based on adaptive input–output feedback linearization control (AIOFLC). The controller computes the reference voltages of the inverter to bring active and reactive power errors to zero without any inner current loop. With a suitable Lyapunov function, the control law and the estimation laws for inductance and resistance of filter and line are obtained in synchronous reference frame. The proposed controller has a simple structure which needs less computation and increases accuracy. Using space vector pulse width modulation (SVM), a fixed switching frequency is achieved which simplifies harmonic design of AC filter and more utilizes DC voltage source. The parameters of filter and line are uncertain or unknown; only their nominal values are available. Simulation results show the capability and effectiveness of the proposed AIOFLC in direct active and reactive power control in several case studies considering various unknown filter/line parameters.