HYBRID SOLAR POWER PLANT
The solar power plant technology selected in this project is hybrid type, which allows battery charging as well as energy export to utility grid for banking and net metering. The solar array of the solar plant shall generate DC electricity during sunshine, in proportional to the intensity of sunrays falling on to the array. The MPPT charge controller 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.
This DC electric power is used to charge the battery and also converted in to AC electricity by the hybrid inverter of the plant and synchronizes with utility grid power. This electricity generated can be used against the load connected. The balance is exported and banked at grid through a net metering system. The inverter shall have a priority feature and with this priority operation, the source of power to the load connected shall be ‘first the solar power generated and then EB grid/battery bank’. In case the grid fails during sunshine hours, the plant shall go on to off-grid mode and continue to generate solar power for the load connected In the case when the grid fails during non-sunny hours, the battery bank associated with solar hybrid power plant shall power the load connected within the inverter and available battery bank capacity.
ON-GRID SOLAR POWER PLANT
The solar array of the solar plant shall generate DC electricity during sunshine, in proportional to the intensity of sunrays falling on to the array. The MPPT charge controller 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. This DC electric power is converted in to AC electricity by the grid-tie inverter of the plant and synchronizes with utility grid power. This electricity generated can be used against the load connected. The balance is exported and banked at grid through a net metering system. The inverter shall have a priority feature and with this priority operation, the source of power to the load connected shall be ‘first the solar power generated and then EB grid’. In the absence of grid power for synchronization, the plant shall go on to standby mode to ensure the anti-islanding protection.
OFF-GRID SOLAR POWER PLANT
This is a standalone type and designed to produce electricity using solar photovoltaic technology along with a battery bank storage facility. The MPPT Charge 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.The inverter shall convert DC AC and power the load connected. The inverter output shall be of pure sine wave and match the grid in voltage, frequency etc. The output of the PCU shall be connected to the load with a load swapping method to maintain the peak connected within 60% of the inverter limit to ensure smooth backup running during night hours. Day hours when PV power is available it shall be directed to the load and the excess power shall be used for charging the batteries; so that the power from solar is not wasted. The Inverter (PCU) shall be programmed for solar priority mode of operation. This means the maximum use is made of the solar energy. Grid power shall be connected as the backup, which eliminates the need of DG backup. The inverter shall switch over to Grid power when the batteries are over discharged or sufficient solar energy is not available from the PV array. Disengage from the grid, solar plant shall keep supplying the power to the dedicated load, ensuring uninterrupted supply.