Photovoltaic grid-connection composite control strategy in microgrid

Two photovoltaic (PV) grid-connection composite control strategies are, respectively, proposed based on synchronous rotating coordinate transformation and stationary coordinate, in order to enhance the availability of PV grid-connection inverters and satisfy the demand of electricity consumers for power quality. The performance of two composite controls is compared from several aspects of control structure, regulating precision, digital realisation, and amplitude limitation control. In MATLAB/Simulink, the simulation model is built to verify the effectiveness of the proposed composite control strategy under different simulation condition of light intensity and non-linear load. Composite capabilities of harmonic suppression and reactive compensation of PV grid-connection inverters are also verified using the proposed control strategy, which influences the PV generation.