Flux Leakage and Cost Optimized Design of BLDC Motor for Sensorless Solar Powered Water Pumping

This paper presents a flux leakage and cost optimized design of a 2.2kW permanent magnet brushless DC motor for solar photovoltaic (PV) feed water pumping for agricultural and domestic application. A flux leakage optimization based design is presented here to minimize the flux leakage and to maximize the linkage flux available as per the maximum air gap flux density. A parametric analysis is done for optimizing the magnet used for rotor pole inside the motor. Optimizing the flux leakage and use of magnetic material increase the motor efficiency and reduce the motor cost in comparison with the available PMBLDC motor of same rating. A position sensorless control is implemented to verify the performance of the designed motor as well as the whole system when coupled with the water pumps and fed from the solar photovoltaic array. The developed sensorless control is compatible for both surface mounted and submersible type water pumping applications with high water pressure column. The design reliability of the developed motor and the sensorless motor drive are verified with the analytical results and experimental results tested on a fabricated motor and developed drive prototype.