Selection and Design of Solar Water Pumps in Photovoltaic Water Pumping Systems

Selection and Design of Water Pumps in Photovoltaic Water Pumping Systems

• Motor and pump

• Selection and design of solar water pump

Motor and pump

All the measures of the photovoltaic water pump system are to produce more water stably and reliably, they must be implemented on the work of the motor and the water pump. For the photovoltaic water pump, the combination of the motor and the water pump is not like the common motor and water pump. The collocation is so "casual", because the power level and voltage level of the motor are largely restricted by the voltage level and power level of the solar cell module, so when the requirements for the lift and flow of the pump are reflected on the motor, it must be specially designed under the condition of taking into account the structure of solar cell modules. 

Due to the different requirements of different users, the driving motors for photovoltaic water pumps include : 

• Traditional DC motors of different voltage levels

• DC brushless permanent magnet motors 

• Three-phase asynchronous motors 

• Permanent magnet synchronous motors

• Reluctance motors 

Judging from the current usage situation, three-phase asynchronous motors and DC brushless motors are the most, and high-power systems still mainly use high-efficiency three-phase asynchronous motors. When designing the motor, it is necessary to fully consider the specific operating conditions of the photovoltaic water pump, mainly: frequency conversion operation, large changes in load rate sooner or later, etc. In this case, we must strive to make the motor the highest average efficiency throughout the day and year. Unlike ordinary motors, it can be considered that it is always working under the power supply with constantvoltage.In remote communities, it is one of the most ideal ways to use solar photovoltaic system-powered water-lifting equipment to solve the drinking water and irrigation problems for people and animals in these areas without electricity. On the one hand, some areas are rich in solar energy resources; on the other hand, photovoltaic water pumping equipment has no pollution, no noise, high reliability, minimal maintenance workload, and low cost, which is about half lower than the cost of diesel engine water pumping. And its reliability far exceeds wind power to lift water.  With the renewal and research and development of solar cells,  the application prospect of photovoltaic water pumping will be broader. 

Photovoltaic water pump system consists of 4 parts: solar cell components, control (inverter), motor and water pump system.

The selection and design of the water pump in the photovoltaic water pump system are also very characteristic. According to the different requirements of users for flow and head, the pump type can be selected according to the following principles in terms of economy and reliability: users who require small flow and high head should choose positive displacement pumps; users who require larger flow and higher head Users who need to use submersible electric pumps should choose submersible electric pumps; users who need large flow but low lift should generally use self-priming pump motors and water pumps.