Research On Single Phase Permanent Magnet BLDC Motor Control System

With its significant advantages,such as simple structure,low cost,single-phase permanent magnet BLDC motor has been very widely used.However,people also put forward higher and higher requirements for its good performance.This not only embodies in motor ontology structure need to be further optimized,but also the research of single-phase permanent magnet BLDC motor's low torque ripple and high efficiency operation is the development trend of the future.In order to solve the problem of "starting dead point" of single-phase permanent magnet BLDC motor,the motor is often designed with non-uniform air gap structure.But the larger cogging torque has great influence on the output torque ripple of the motor.In this paper,in order to make the output torque of single-phase permanent magnet BLDC motor is improved,based on consulting a large number of domestic and abroad relevant books and literature,by using energy method and Maxwell stress tensor method to analyze the cogging torque of single-phase BLDC motor.Then,the torque compensation control method based on feedforward adaptive control is proposed.By the feed-forward compensation of the quadrature axis current component,the generated electromagnetic torque and the cogging torque are mutually compensated to reduce the motor output torque ripple.In order to realize the high efficiency control of single-phase permanent magnet BLDC motor,the key points of high efficiency control are analyzed in this paper.And refer to the space vector control mothed that widely used in three-phase permanent magnet BLDC motor,a novel vector control strategy for single-phase PMBLDC motor is proposed.In the proposed mothed,by constructing the virtual phase current,which is orthogonal to the real phase current,the two-phase orthogonal stationary coordinate system is constructed.Then,through the Park rotating coordinate transformation and double current closed-loop control,using the single-phase SVPWM modulation technique to control the output,achieve the vector control of single-phase PMBLDC motor.In addition,an improved simple sinusoidal current control method based on inner power factor angle closed-loop is proposed.Finally,the experimental results show that the vector control method of single-phasePMBLDC motor and the improved simple sinusoidal current control method can all achieve high efficiency operation in the wide load range,and the current Waveform sinusoidal good,vibration and noise in the motor has also been significantly improved.However,from the overall control performance,the vector control method is better than the improved simple sinusoidal current control.