PWM Speed Control of Brushless DC Motor for Inrush Current Regulation of Solar Water Pumping System

The increasing utilization of electricity, high diesel costs, and global drive towards reducing carbon footprint made solar-based water pumping a promising and viable alternative to conventional electricity and diesel-based water pumping system. The significance and abundant availability of solar energy in the Philippines is at large due to its geographical location and has been effectively utilized for powering electrical loads with different applications such as direct current (DC) motor. The main objective of this study is to design and implement a brushless dc (BLDC) motor-based solar water pumping system with improved in-rush current load regulation. Speed control of BLDC motor is very important for critical conditions like current surges which is proportional to power surges resulting to a greater system loss. Hence, the proposed design uses pulse width modulation (PWM) method as an efficient and dynamic BLDC motor speed control. ATMEGA2560 microcontroller controls the settling time of the PWM duty cycle in proportion to the speed and power requirement of the motor thus, regulating the startup surge current of the dc motor. Results on the actual tests confirm that the successfully implemented system design can be used for any water pumping system in rural and urban areas and can improve the inrush current regulation effectively.