Conceptual Design of a Sensorless Closed Loop V/f Controlled Integrated Induction Motor Drive System

In this study, a fully integrated, high-power-density drive system is developed and embedded into the end plate of a 1.5 kW, 400 V/50 Hz three-phase induction motor (IM) to address the limitations of conventional drive systems connected via long cables, such as electromagnetic interference (EMI), reduced efficiency, and bulky structures. Unlike traditional motor-drive configurations, the proposed circular PCB layout, designed through an electro-mechanical co-design approach, enables compact integration of the inverter, microcontroller, and heat sink inside the motor enclosure. This eliminates external cabling, minimizes EMI, and improves thermal management. Moreover, a sensorless closed-loop V/f control strategy is implemented to ensure robust speed regulation without mechanical sensors, reducing cost, wiring complexity, and reliability concerns. By combining optimized power electronics, effective thermal design, and sensorless control, the proposed system achieves compactness, higher efficiency, and enhanced reliability, making it well-suited for industrial applications requiring high power density and robustness.