A small grid-connected PV system controlled by the PLC

A new working of the PV system is proposed in this paper. The general solar power generation system can intelligently switch into three work models by the programmable logic controller, including power supply, power storage and grid-connection, The power curve of the PV system can be summarized from the generation data detected by the data acquisition system, compared with the power curve of the various binary combined air-condition loads, we can identify the optimal matching control strategy between the PV system and the combined air-condition loads. The solar power generation system can charge the battery, so the storage power will be converted into AC for the load by independent inverter when the PV power is insufficient; the PV system also can intelligently convey energy to the grid, the grid has the two-way transmission function, in other words, the grid also supply the energy to the load if the PV system fail to drive the load. All in all, the system is capable of bi-direction power transfer.