Improved Vector Control Scheme for Voltage Source Inverter Driven Induction Motor Drives

With the growing adoption of renewable energy, solar photovoltaic (PV) based induction motor drives are gaining popularity. However, extraction of maximum power from solar PV arrays and high-performance control of induction motors poses significant challenges. This paper proposes a three-stage solar powered improved indirect vector controlled induction motor drive for optimal PV power harvesting and superior speed regulation. An incremental conductance (InC) maximum power point tracking algorithm and DC-DC buck converter rapidly extract peak power from the PV array under varying irradiation. A buck-boost converter maintains a steady DC voltage supply to the voltage source inverter (VSI) despite fluctuating PV output. Rotor flux-oriented indirect vector control of the induction motor decouples the torque and flux components in the stator current to achieve fast, accurate speed control similar to DC drives. Detailed modeling and simulation of the overall system is carried out in the MATLAB/Simulink platform. A small-scale experimental prototype is developed to verify the effectiveness of the scheme. The proposed improved controller overcomes the limitations of the conventional solar-powered scalar controlled and direct torque-controlled induction motor drives in terms of slower dynamics, torque pulsations, and limited speed range. This indirect vector control scheme demonstrates precise speed regulation and faster response due to independent flux and torque control in conjunction with maximum utilization of PV power.