The Solar Photovoltaic (PV) modules convert solar radiation from the sun into electrical energy in the form of direct current (DC). The Solar Charge Controller (SCC) part of PCU then maximizes the use of this electrical energy to charge the battery bank and at the same time it prevents over charging of the battery bank.
The power generated from the PV Modules will be supplied to the load through solar inverter unit (part of PCU), which converts DC power to pure Single Phase or Three Phase AC sine wave power depance on the system. The inverter unit will power the dedicated loads either from the solar array or battery bank in that order of preference. The single phase inverter is designed for catering the power needs of the load.
The MPPT Charger controller shall power the DC bus from the PV array. The microprocessor control circuit shall automatically adjust the DC-DC converter to ensure that it should always match to the PV array under varying conditions and transfers the maximum possible power. The battery bank shall get charged from this DC bus, the charging rate and other parameters being controlled by the supervisory circuit.
A bidirectional inverter shall sit between the DC and the AC bus. The DC power shall be converted to AC and exported to the grid. The inverter output shall match the grid in voltage, frequency and phase. The PCU shall have the provision for connecting to a dedicated load. If the grid is absent or goes out of range the inverter shall not interrupt supply. If PV power is available it shall be directed to the load and the excess power shall be used for charging the batteries. So the power from the Solar is not wasted. The Inverter shall be programmed for solar priority mode of operation. This means that the maximum use be made of the solar energy. Grid power shall be used only when the batteries are over discharged or sufficient solar energy is not available from the PV array. Disengage from the grid and shall keep supplying the power to the dedicated load, ensuring uninterrupted supply.
If PV power is available this is now directed to the load and the excess power is used for charging the batteries. So the power from the Solar is not wasted. The Inverter is programmed for solar priority mode of operation. This means that the maximum use is made of the solar energy. Grid power is used only when the batteries are over discharged or sufficient solar energy is not available from the PV array.