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一种新颖的SPMSM驱动系统自适应死区补偿方法

2021-03-22于子淞

电脑知识与技术 2021年4期

摘要:逆变器死区效应将造成电机电流畸变,为提高表贴式永磁同步电机电流控制精度,提出一种自适应死区电压补偿策略。该方法利用参考电流建立d、q轴死区电压核函数,能够在表贴式永磁同步电机电阻、电感参数未知的情况下,对d、q轴死区电压的幅值进行辨识,将辨识的电压幅值与其核函数相乘得到所需补偿的死区电压。从而解决了输死区电压造成的相电流畸变难题。仿真结果表明,所提出的电流控制策略能够有效减少相电流谐波含量、提高电流控制精度。

关键词:表贴式永磁同步电机;驱动系统;死区效应;相电流畸变;自适应补偿

中图分类号: TP273        文献标识码:A

文章编号:1009-3044(2021)04-0015-04

Abstract: The deadtime effect of voltage source inverter (VSI) produce the phase current distortion of the motor. In order to enhance the current control accuracy of the surface mounted permanent magnet synchronous motor (SPMSM), an adaptive deadtime voltages compenation strategy is proposed. The proposed method uses the reference current commands to model the kernel function of the d and q axes deadtime voltages and then identifies the ampitudes of the d and q axes deadtime voltages in the case of unknown resistor and inductance of the motor. The compensated deadtime voltages are equivalent to the product of identified amplitudes and kernel functions. Then, the problem of phase current distortion is successfully solved. The simulation results show that the amplitude of phase current harmonics are reduced effectively, and the current control accuracy is enhanced.

Key words: surface mounted permanent magnet synchronous motor; drive system; deadtime effect; phase current distortion; adaptive compensation

表貼式永磁同步电机(SPMSM)功率密度高、输出转矩与q轴电流成比例,被广泛应用于高精度伺服系统[1]。矢量控制技术采用级联控制结构,电流控制性能决定了转矩控制精度和电机铜耗,是影响调速系统性能的关键因素。常规PID控制简单易行,但对系统参数和外界扰动的鲁棒性较差。针对这一缺点,文献[2-4]分别提出自适应PID控制[2]、模糊PI控制[3]、模型预测控制[4]以提高电流控制精度。

当电机运行于低速轻载工况时,逆变器死区效应将造成电机相电流畸变严重[5]。重复控制[6]能够有效抑制系统周期扰动,但电机低速运行时,该算法需要存储一个周期电流的采样值,这对CPU的内存消耗较大。文献[7]提出一种在线延时补偿算法,该算法可省掉开关器件没有必要的开通和关断,具有输出电流谐波含量小的有点,但该方法需要在线计算电机反电动势,电机温度的变化会造成反电动势计算出现误差,进而影响补偿精度。……

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