This article proposes an improved DC-link series IGBT chopping strategy for the brushless DC motor (BLDCM) drive equipped with a small DC-link capacitor fed by single-phase AC source. In this strategy, different vector sets are established according to the switching state of the DC-link IGBT and the operation mode of BLDCM. By analyzing the effect of each vector on phase current change rate, a vector selection-based current control scheme is presented. In particular, when the rectifier output voltage is less than the average line voltage of BLDCM, the combined action of vectors with only DC-link IGBT chopping is designed, in order to decrease the converter switching times and reduce the DC-link capacitance at the same time. In addition, the constraint of the DC-link capacitor voltage is analyzed to satisfy the reliable regulation of the motor phase currents, and the calculation method of the DC-link capacitance is given furthermore. The proposed strategy can achieve the smooth operation of the motor with small DC-link capacitance. Meanwhile, the total switching times of the converter are reduced, thereby improving the converter efficiency. The contrastive experimental results verify the correctness of the theories and the effectiveness of the proposed strategy.

中文翻译：

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具有小直流母线电容的无刷直流电动机驱动器的改进型DC-Link系列IGBT斩波策略

本文提出了一种改进的DC-link系列IGBT斩波策略，适用于无刷直流电机（BLDCM）驱动器，该驱动器配备有一个由单相AC电源馈电的小型DC-link电容器。在这种策略中，根据直流母线IGBT的开关状态和BLDCM的工作模式建立不同的向量集。通过分析每个矢量对相电流变化率的影响，提出了一种基于矢量选择的电流控制方案。特别是，当整流器输出电压小于BLDCM的平均线电压时，设计矢量的组合作用，仅采用直流环节IGBT斩波，以减少转换器的开关时间并减少直流环节的直流环节电容。同时。此外，分析了直流环节电容器电压的约束，以满足对电机相电流的可靠调节，并给出了直流环节电容的计算方法。所提出的策略可以以较小的直流母线电容实现电动机的平稳运行。同时，减少了转换器的总开关时间，从而提高了转换器效率。对比实验结果验证了理论的正确性和所提出策略的有效性。