Adaptive Compensation Method for High-Speed Surface PMSM Sensorless Drives of EMF-Based Position Estimation Error

Abstract

To improve the performance of the surface permanent magnet synchronous motor (SPMSM) drives, a sensorless control scheme based on the sliding-mode observer (SMO) with an orthogonal phase-locked loop (PLL) incorporating two synchronous frequency-extract filters (SFFs) is proposed. The rotor position estimation errors are analyzed. The analysis results show that the harmonic errors of the estimated signal are hardly to eliminate completely. Therefore, an improved adaptive notch filter (ANF) -the SFF is proposed to extract the fundamental wave of the rotor position estimation before applying to the PLL. This method of the PLL combined SFFs can compensate the estimated back electromotive force (EMF) harmonic error efficiently and adaptively. An experimental driveline system used for testing the electrical performance of the developed magnetically suspended motor is built. The effectiveness and the feasibility of the proposed method are validated with the experimental results. Key words-sensorless, rotor position estimated error, adaptive compensation, high-speed surface permanent magnet synchronous motor (SPMSM), Sliding-Mode observer (SMO)

Sensorless Scheme for Interior Permanent Magnet Synchronous Motors with a Wide Speed Control Range

“…The equations rearranged with differential form of motor currents can be expressed as (3). Subscript c represents the value in the controller.…”

“…The back-EMF detectionbased scheme estimates the rotor position by manipulating the errors between stator currents in the controller and those from a motor model. Basically, this method employs the discrete current values from motor state equations and sometimes applies complex observer schemes [3], [4]. The precision of the estimated position is highly affected especially at low-speed operation by the accuracy in motor parameters and nonlinearity in inverter output voltage such as dead-time effect [5].…”

Determining the observer parameters for back EMF estimation for selected types of electrical motors

“…For this purpose a various method may be used, e.g. methods based on the Luenberger observer [1] and modified Luenberger observer [3], sliding mode observer [4], or methods which use Kalman filter [5] [6]. Expansion of the correction function of Luenberger observer from proportional form into form of proportional-integral improves observer's performance in case of rapid changes of speed and improves robustness on electromagnetic disturbances [7].…”

Iterative sliding mode observer for sensorless control of five-phase permanent magnet synchronous motor

“…For the electric drive system of five-phase PMSM, the conventional control strategy usually needs the information of rotor position and speed for closed-loop control by position sensor such as an optical encoder fixed on the motor shaft [11]. Unfortunately, the position sensor, which is sensitive to the vibration and temperature, restricts the application of five-phase PMSM in electric drive system operated in harsh environmental conditions, and reduces the reliability of the whole electric drive system [12,13].Nowadays, with the development of digital signal processor [14-16], the sensorless control technology has gained more attention in drive control system of three-phase PMSM. The sensorless control techniques are generally divided into two categories which are the high-frequency signal injection method by utilizing the salient effect of PMSM [17][18][19] and the observer estimation method based on all kinds of observers [20][21][22].…”

“…For the electric drive system of five-phase PMSM, the conventional control strategy usually needs the information of rotor position and speed for closed-loop control by position sensor such as an optical encoder fixed on the motor shaft [11]. Unfortunately, the position sensor, which is sensitive to the vibration and temperature, restricts the application of five-phase PMSM in electric drive system operated in harsh environmental conditions, and reduces the reliability of the whole electric drive system [12,13].…”