A Combining FPE and Additional Test Vectors Hybrid Strategy for IPMSM Sensorless Control

This paper proposes a hybrid strategy by combining fundamental pulsewidth modulation excitation (FPE) and additional test vectors, which is used in interior permanent-magnet synchronous motor (IPMSM) sensorless control. In contrast to the typical indirect flux detection by on-line reactance measurement-based methodology where the rotor position is calculated and updated in every three successive pulsewidth modulation (PWM) cycles, the proposed hybrid strategy can achieve the one-cycle acquisition of the rotor position by utilizing both response currents of FPE and additional test vectors, which makes the proposed strategy more robust and suitable in higher speed or load sudden change conditions. Meanwhile, a new PWM scheme for four-space-vector PWM (FSVPWM) is presented, which sharply simplifies the implementation process. Furthermore, for the case that the amplitude of the object fundamental voltage is so small that it cannot satisfy minimum time demand for the slopes of response currents sampling, a compensation technique is presented. In addition, the multiple-point current sampling (MPCS) technology and linear least square fitting method are used to decrease the current sampling disturbance, which improves obviously the accuracy of position estimation. Finally, the experimental results confirm that the proposed strategy can obtain the rotor position accurately and simply.