Solar Powered Higher-Order Sliding Mode Observer based Sensorless Synchronous Reluctance Motor Drive for Water Pumping and EV Battery Charging System

This paper presents an innovative approach comprising coordinated subsystems for battery charging and water pumping within an agri-voltaic framework. The system is designed to improve efficiency and sustainability of agricultural operations by effectively utilizing solar photovoltaic (PV) energy. In this setup, PV array is integrated into agricultural land, enabling renewable energy generation without affecting crop production. Generated solar power is intelligently managed to serve two key functions: charging electric vehicle (EV) batteries and powering a water pump for irrigation. To ensure maximum energy extraction, an incremental-conductance-based maximum power point tracking (MPPT) algorithm is employed. A bidirectional DC–DC converter (BDDC) is used to regulate energy flow for EV battery charging. For water pumping subsystem, a synchronous reluctance motor drive (SyRMD) is controlled using a sensorless field-oriented control (FOC) strategy. For FOC of SyRMD, reference quadrature-axis currents are determined based on both the pump characteristics and available PV power. The rotor position required for sensorless control is estimated using a full-order sliding mode observer (SMO) integrated with a mixed second-third order generalized integrator (MSTOGI)-based phase-locked loop (PLL). Finally, performance of the proposed system is validated through experimental testing on a laboratory-scale prototype under varying solar irradiance conditions.