Permanent Magnet Brushless DC Motor Sensorless Control for Solar-Powered and Grid-Integrated Water-Pumping Systems

Abstract

Permanent magnet brushless DC motors (PMBLDCM) are at the core of most water-pumping systems, which are increasingly moving towards the integration of solar photovoltaic power in domestic, agricultural and industrial applications. However, these systems often face power intermittency due to variable environmental conditions and nighttime outages, leading to underperformance. This study tackles the inherent challenges in ensuring efficient, stable, and cost-effective operation of PMBLDCMs in hybrid solar-grid water-pumping systems without position sensors. The proposed control method integrates an adaptive proportional resonant controller-based phase-locked loop (PLL) to enhance system reliability and performance, ensuring smooth grid interaction with minimal power fluctuations, along with a novel sensorless commutation algorithm for precise rotor position estimation. The proposed control system requires only one line voltage for position estimation, and one phase current for estimation refinement under varying dynamic conditions. The proposed system is validated through an experimental approach, demonstrating its potential to significantly improve the efficiency of solar-powered grid-integrated water-pumping systems, by allowing for a 17% load capacity increase, and 13 % reduction in system costs, making it a significant improvement over existing methods.