Independent control of active and reactive power of the grid-connected inverter

For the mathematical model of PWM inverter under the d-q rotary coordinate system, there exists coupling between the active current and reactive current, which makes it difficult manipulating the power injected into AC grid from distributed generation system. So as to handle the problem, a novel current decoupling strategy based on the input-output linearization is employed in the paper and the PI controllers are designed in the paper, whose application effectively eliminated the interaction between the active current component and reactive current component, equipping the system with fairly excellent linear control characteristic. Simulation results demonstrate that the method adopted possesses excellent decoupling performance.