无刷直流电机(BLDCM)直接转矩控制系统中,相电流的正确检测是实现转矩控制的前提。研究了BLDCM电磁转矩与相电流的关系,设计了相电流检测的硬件电路与软件算法。由霍尔电流传感器检测出相电流大小,经调理电路送入DSP的AD转换模块。针对AD转换带来的偏移和增益误差,采用最小二乘法及线性拟合函数进行数据校正；针对个别数据导致的偶然误差,提出了电流复合滤波方法；针对周期性干扰,在AD校正后加入了一阶滞后滤波。试验结果证明,所采用的相电流检测与处理方式降低了电流检测误差,实现了转矩的实时观测与直接控制,有效抑制了转矩脉动。

The correct detection of phase current was the premise to realize torque control in brushless DC motor (BLDCM) direct torque control system. The relationship between electromagnetic torque and phase current of BLDCM was studied. The hardware circuit and software algorithm of phase current detection were designed. The phase current was detected by Hall current sensor and transferred to the AD conversion module of DSP through conditioning circuit. For the offset and gain error caused by AD conversion, the least square method and linear fitting function were used to correct the data. Aiming at the accidental error caused by individual data, a current composite filtering method was proposed. A firstorder lag filter was added to the AD correction for periodic interference. The experimental results showed that the phase current detection and processing method greatly reduce the current measurement error, realized the realtime observation and direct control of torque, and effectively inhibited the torque ripple.

TM 33

江苏省政策引导类计划(国际科技合作)——重点国别产业技术研发合作项目(BZ2018045);盐城工学院研究生创新工程项目(SJCX17_YG03)