Performance of Solar PV System with Self Regulating Module for Micro DC Submersible Pump

Solar operated pumps are becoming the need of the hour, particularly in the remote areas where grid power is not available. Micro DC solar submersible pumps (less than 50 W) needed where water availability is less and the bore recuperation rate is very low. The available solar DC submersible pumps have capacities ranging from 400 watt to 15 kW with very high discharge rates. These pumps are therefore not suitable for bores with low recuperation rates. Further, these pumps use maximum power point tracking charge controller for their operation, adding to the system cost. Actual selection of the pump depends on the head and the discharge requirement. In the present work, a pump is coupled to a 35 watt DC motor. The Maximum operating voltage that the motor can sustain is around 14 Volts. The standard Solar PV Modules available in the market have V_max around 17.3 Volts which is much higher than the required operating voltage of the motor. These modules, if used, need charge controller to be placed in between the PV modules and the motor. Instead, Solar PV Modules having Vmax suitable for the DC pump operation are designed and manufactured so that charge controller can be eliminated. Such modules are also called as self regulating PV modules. This paper describes the results of the experimentation carried out to study and compare the performance of the pump with standard as well as self regulating Solar PV Modules. The results obtained are encourageous as self regulating modules were found to perform better than the standard ones.