一种提高变流器效率的无刷直流电机速度控制策略

Speed control strategy to improve converter efficiency for BLDCM

针对直流链采用小电容的无刷直流电机系统,以减少开关管动作次数,有效提高变流器效率为目标,提出了一种新型控制策略。该策略根据电机运行工况调整电容供电区间,当电机运行在非额定工况时能够避免直流链开关管不必要的斩波。此外,在电容供电区间,单独控制直流链开关管斩波来实现直流链输入电压和电机转速的同时调节,进一步减少了变流器开关管动作次数。对无刷直流电机平稳运行时的导通两相线电压平均值进行了推导,并在一套无刷直流电机系统上进行实验,实验结果证明了本文提出方法的有效性。

To reduce the action number of converter switches and effectively improve the converter efficiency,a new control strategy is proposed for BLDCM system with small DC-link capacitor.The proposed method adjusts the capacitor power supply interval according to the operating conditions of the motor,and the unnecessary chopping of the DC-link switch can be avoided when the motor is running under non-rated conditions.In addition,the DC-link switch is controlled to chop solely to realize the simultaneous adjustment of the DC-link input voltage and the motor speed in the capacitor power supply interval,which can further reduce the action number of converter switches.In this paper,the average line voltage of two conducting phases for brushless DC motor is derived,and the experiments are carried out on a set of BLDCM system.The experimental results demonstrate the effectiveness of the proposed method.