Research on Seamless Switching Control Strategy of PV Generation System With Dual-mode Operation

Solar photovoltaic systems have independent and grid-connected operation modes, seamless switching between these two modes is one of the key issues of grid-connected techniques for DG generation system with dual-mode operation. A control strategy is proposed based on the analysis of PV system characteristics, in which multi-loop feedback control is taken for the inverter of photovoltaic generation, voltage weighted control is added in the grid-connected process, and the current weighted control is also added in the independent process. Therefore, it inhibits the impact of grid-connected current and the load voltage in the switching process, and makes their fluctuation within the permissible range. The PV generation system with dual-mode operation system is simulated and analyzed by using PSCAD/EMTDC software, and the results show that the seamless switching control is realized and the feasibility and effectiveness of the proposed control strategy are verified.