IMP-based synchronization controller for distributed three-phase inverter with uncertain loads

With more and more distributed and renewable energy sources connected to the utility network, it will introduce different dynamics to the system, and power electronics interfaces are needed to enable efficient and flexible interconnections among different players. Based on Internal Model Principle, sinusoidal denominator can be included in the cascaded controller for DC-AC inverter to achieve the synchronization control for the tracking of grid voltage. However, the load variation is quite normal in the operation of power grid. In this paper, after the controller design is performed based on nominal load, robust stability analysis is made to define the tolerance boundary for the resistance variation, inductance variation, and capacitance variation, respectively. Finally, the proposed boundary is verified with MATLAB simulation.