Sensorless Field Oriented Control of Brushless Direct Current Motor with Disturbance Compensated Sliding-Mode Observer

This paper presents a senseless control algorithm for brushless direct current motors (BLDCM). The method can shift BLDCMs from a static state to a stable state of high speed rotation. Initially, when the motor operates at low speed, a opening loop speed control is employed to propel the motor towards the state from open loop to close loop. Subsequently, upon reaching this state, the sliding-mode observer (SMO) is utilized to estimate the position and velocity of rotor, facilitating the integration of the field-oriented control (FOC) algorithm. The classical FOC algorithm is augmented with a disturbance compensation component in the q-axis current, significantly enhancing anti-load disturbance ability of the system. Through simulation and experimentation, the control method can make the BLDCM quickly respond to the stable state in about 1 s, and the error falls into 0.33%. The efficacy of this control methodology is validated.