A Novel Hybrid Control Algorithm for Suppressing the Resonance of Multiple Inverters in Parallel

In order to suppress the resonance for LCL type multi-inverters parallel system, a new hybrid control algorithm for autonomous order reduction is proposed in this paper. Based on the hierarchical control structure of inverter, the two-degree-of-freedom control principle is combined with the current prediction model control. Thereinto, together with current model prediction control, the current inner loop of control layer can eliminate PI controller and PWM regulator and realize transfer function unitization of the current inner loop for order reduction. In the voltage outer loop of control layer, the principle of two degrees of freedom is adopted to construct the inverse model of the controlled object. And based on the current model predictive control of inner current loop, the unit transfer function of the control layer is realized. At this moment, only the application layer transmission function is left in the multi-inverter parallel system, the highest order difference between the numerator and the denominator of resonance transfer function is autonomously decreased. Finally, through drawing the bode diagram of the transmission function, the proposed algorithm is verified to suppress the resonance in multi-inverters parallel system. And its correctness and effectiveness are also verified by MATLAB/Simulink simulation system.