Inverter synchronization control with Internal Model Principle

With the recent soaring of renewable energy, future power grid will likely evolve in a Distributed Power Generation System. These changes lead to a critical concern that is how to effectively maintain the synchronization between distributed generators / inverters and power grid. In this paper, Internal Model Principle is utilized to construct controller for the regulation of both voltage and phase angle in DC-AC inversion. Through controller innovation, conventional Phase Lock Loop is not needed anymore, and true synchronization can be realized. Furthermore, to enhance stability, Linear Quadratic Regulator is introduced to achieve optimization. Then digital redesign is conducted to obtain the corresponding discrete-time controller in z-domain, which can effectively prolong the calculation period to lessen computational burden in real-time. Simulation results confirmed the effectiveness of the proposed method.