Application of power combination technology based on phase shift pulse-width modulation (PMW) control policy in photovoltaic grid-connected system

The invention relates to a power combination mode based on a phase shift pulse-width modulation (PMW) control policy. In the mode, a plurality of power devices are combined in parallel, the number of combinations can be automatically identified through a controller area network (CAN) system, and a plurality of single phases can be connected in parallel to form a three-phase system through setting; meanwhile, the system automatically searches for a main control machine, and the acquired main control machine realizes data sharing by means of the CAN bus; and if a certain machine breaks down, the machine automatically quits the parallel system to realize parallel redundancy of the system. A phase- shifted full bridge is utilized to achieve the purpose of improving the efficiency of the wholemachine. By using the modularized structure, the fault redundancy capacity of the system is improved, safe and reliable operation of a photovoltaic grid-connected generation system can be ensured, and particularly, power values can be combined randomly, thus meeting the power requirement of high-capacity grid-connected generation. In addition, the standardization and modularization of the system can effectively reduce the cost of a grid-connected inverted power supply.