Current Control of Sensorless BLDC Motor Using Hysteresis Control

The superior performance and operational benefits of brushless DC (BLDC) motors have increased their adoption in several industries. As BLDC technology continues to progress, its impact on various industries is expected to grow. Brushless motors with and without sensors offer precise control and smooth operation at low speeds. Even though motors with sensors provide higher speeds and more cost-effective operation, more power can be extracted from sensorless motors. Sensorless BLDC motors depend on estimation techniques to calculate rotor position, which means that estimation accuracy is crucial for their performance. For that, a new approach for determining commutation instants is presented in this work, which is the Volt/Hz method. By comparing line-to-line voltages and their differences, unit templates are generated. Hysteresis controllers are used to provide precise adjustments and efficient performance for BLDC motors, which minimizes error. This technique, which does not rely on back-EMF zero-crossings, offers a distinctive viewpoint. To achieve the Volt/Hz method, the switching pulses are generated by using the hysteresis controller. To fully study and confirm how well this BLDC drive works with the new methodology, simulations are done in the MATLAB/SIMULINK environment.