Brushless DC Motor Sensorless Controller With Extended Speed Range

A brushless DC motor sensorless control algorithm is proposed. The features of the proposed approach are: simplified BLDC controller circuitry, absence of dedicated zero-crossing comparators for sensorless rotor position detection. Also, there is only one signal that is processed – this reduces the requirements for number of multiplexed ADC inputs. The proposed control algorithm could be used with PWM regulation; the operational speed range is limited only by ADC accuracy parameters. The main feature of the proposed control method is that it allows to implement multiple BLDCs controller using a single microcontroller having built-in ADC and timers with PWM capability, with relatively low usage of its processing power. In the article, a description of the proposed algorithm is presented. The theoretical results were experimentally verified and proven, the description of an experimental setup is given. The proposed approach to BLDC control may find its use in development of drones with custom aerodynamic and control system by enabling high degree of integration of processing functions in one microcontroller, thus reducing the system BOM cost.