Fundamental Research

Soft mobility: Sensorless control of synchronous machines

Electric mobility is a key solution for reducing CO2 emissions and combating global warming. In this context, PhD research conducted at IFPEN focused on developing a sensorless control method for permanent magnet synchronous motors (PMSMs) operating at extra-low voltage (48 Vdc) and intended for sustainable electric vehicles, such as license-free cars, scooters, and electric bicycles. This control method, based on the acquisition of electrical signals and the injection of high-frequency (HF) signals, eliminates the need for a mechanical position sensor, thereby reducing manufacturing costs while ensuring accurate estimation, particularly at low speeds and when stationary. A method for optimizing the amplitude of HF injection, based on a digitally enriched experimental database, was developed to limit disturbances induced on the system, such as torque oscillations and energy consumption, while ensuring reliable estimation. This approach has been experimentally validated and can be easily adapted to other types of electric machines. It offers an industrializable solution for a variety of applications.