Solar Pump Inverter, controls and regulates the operation of PV water pumping system (solar water pumping system), converts the DC power from PV array into AC power to drive the pump, and adjusts the output frequency in real time according to the change of sunshine intensity, in order to achieve the maximum power level tracking.
Solar pump inverter is one of the many classifications of inverters, and the main function is the same as our common grid-connected inverter, which is to convert PV DC power into AC power. However, pump inverters have made many improvements to save a lot of cost for the system and expand the scope of PV applications.
Solar pump inverter is off-grid inverter, not dependent on the grid and can work independently with load, but the conventional off-grid inverter needs to work with battery, and the lead-acid battery is expensive, its cost about 30% of the system. The solar pump inverter's life is only 3-5 years, which affects the investment return of the system. The PV water system does not need to be equipped with a battery, it works when there is sunlight. By building a water tower at a high place, and water can be taken from the water tower when it is needed, and the inverter itself will be equipped with a water level switch, which is very convenient and practical.
The motor is the most difficult load to carry in the off-grid system, because it requires a lot of energy to start the motor, the conventional motor starting power is about 3 times the rated power, while the pump motor needs to pump water to a high place, the starting power is about 5 times to the rated power. During normal operation, the input at the DC end must also be greater than 2kW for the motor to run continuously. This increases the cost of the system, while the solar pump inverter adds a special algorithm, which generally only increases the power by 20%, for example, a 4kW pump motor can be started with a 5kW water lifting inverter. During operation, the PV input power has little use to be 4kW to run continuously, about 1kW can also make the pump run.