Robust Control of Active and Reactive Power of a Single Phase Grid – connected Inverter Based on the Current Dynamic Phasor

Due to the need to use clean energy sources and the existence of different single/three phase consumers, the maximum use of single/three phase distributed generation (DG) units in the distribution system becomes crucial. The presence of DG units in the network, because of the need to inverters for exchanging power with the network and nonlinear structure of the inverters, requires control methods with high dynamic and steady-state performance with respect to sudden changes and disturbances.  In this paper, a robust current controller based on the sliding mode control (SMC) in the synchronous dq reference frame is introduced for controlling active and reactive powers of a single phase inverter connected to the infinite bus with constant voltage. By modelling the single phase inverter as a virtual balanced three phase inverter and using the dynamic phasor of the inverter output current, decoupled control of active and reactive powers of the inverter is possible. The performance of the controller for various scenarios of step changes, uncertainty of parameters and external disturbances is evaluated through computer simulations in the MATLAB environment.