High‐Gain Two‐Leg Inverter for Sensorless BLDC Motor Drives in EV Applications

ABSTRACT This paper presents a compact sensorless BLDC motor drive that integrates a high‐gain (HG) DC‐DC converter with a two‐leg three‐phase inverter (TL3‐I). By employing a split DC‐link capacitor to form a virtual third leg, full three‐phase excitation is achieved with only four switches, reducing device count, conduction losses, and driver complexity compared to conventional six‐switch VSIs. A dual‐loop control strategy is employed, where PI‐based duty regulation maintains DC‐link stability, while hysteresis current control ensures accurate current tracking under dynamic load and speed variations. Sensorless commutation is achieved by reconstructing back‐EMFs from line voltages and phase currents, allowing for reliable operation at low speeds where zero‐crossing detection is less effective. Simulation and experimental results demonstrate an efficiency above 92%, stable DC‐link regulation, precise speed tracking from 400 to 2000 rpm, and a smooth torque response of up to 10 Nm. The proposed HG converter‐fed TL3‐I drive demonstrates a promising and compact alternative for electric vehicle applications.