基于电流过采样的永磁同步电机电压脉冲注入无位置传感器控制

Voltage Pulse Injection Based Sensorless Control for Permanent Magnet Synchronous Machine with Current Oversampling Method

针对永磁同步电机低速阶段无位置传感器控制存在动态性能差和稳态精度低等问题,提出一种基于两相静止坐标系的对称电压脉冲注入无位置传感器控制策略,在连续4个PWM周期内注入4个对称电压脉冲,通过电流过采样方式采集相电流并计算电流增量,同时对逆变器非线性因素进行补偿。并将所提方法与改进估计d轴对称电压脉冲注入位置估计算法进行实验对比。实验结果表明,所提两种位置估计策略都能有效实现低速阶段无位置传感器控制,位置估计精度高,且对于额定负载起动、突加/突卸额定负载、速度阶跃信号等表现出优良的动态性能。同时,该策略仅需少量加减法即可获得位置信息,计算量小,易于工程实现。

Aiming at the problem of poor dynamic and low steady-state accuracy of sensorless control for permanent magnet synchronous machine(PMSM)in low speed range,a voltage pulse injection onαβaxis based position estimation strategy is proposed.During 4 consecutive pulse width modulation(PWM)periods,4 symmetrically voltage pulses are injected,and phase currents are sampled by current oversampling method.What is more,a compensation method is adopted to reduce the nonlinear impacts of the inverter.The proposed method is compared with the modified position estimation based on voltage pulses injection on estimated d axis by experiments.The results have verified the proposed two strategies.The position estimation shows high accuracy and excellent dynamic performance under the conditions such as rated load startup,rated load step and speed reference step,and so on.Moreover,the proposed strategies only need several additions or subtractions to obtain position information,which releases computation burden and is easy to implement.