Conference Paper

Comparison of two position and speed estimation techniques used in PMSM sensorless vector control

Ecole Nat. des Sci. Appl., Marrakech MESESYP Lab., Marrakech
DOI: 10.1049/cp:20080597 Conference: Power Electronics, Machines and Drives, 2008. PEMD 2008. 4th IET Conference on
Source: IEEE Xplore

ABSTRACT The paper describes the comparison between two different high-performance techniques used for the sensorless estimation of the motor shaft position in Permanent Magnet Synchronous Motor Sensorless Drives. Rotor position and speed are estimated from measured terminal voltages and currents, and are used as feedback in a sensorless vector control scheme, achieving almost the same high-performance of a sensored drive. The paper point out the differences, by using experimental implementation, between an open-loop flux estimator based on the electrical model of the machine, and a reduced flux observer.

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    ABSTRACT: The paper presents a method to estimate the EMFs and the speed of the permanent magnet synchronous motor (PMSM). The method uses only the measured voltages and currents of the motor; estimation is done using cascaded sliding mode (SM) observers. A first observer estimates the EMFs of the motor in the stationary reference frame; these are obtained by filtering the manifolds of the SM observer. The EMFs are passed to a second SM observer that estimates the speed and re-estimates the EMFs. The method is applicable in sensorless speed controlled PMSM drives where the EMFs are used to obtain the rotor position angle and the estimated speed is used for feedback. The paper discusses the EMF observer - this is a SM design that uses simple manifolds. Then, two versions of the speed observer are presented: the first design uses a single compound manifold; the second uses two manifolds. For both speed observers, the estimated speed of the PMSM is obtained by filtering the switching manifolds of the observer. The theoretical developments are supported with simulations.
    Industrial Electronics Society, IECON 2013 - 39th Annual Conference of the IEEE; 01/2013
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    ABSTRACT: The paper presents a method to estimate the speed and the rotor position of the permanent magnet synchronous motor (PMSM) drive. The development is done using sliding mode theory. The method proposed is based on the model of the PMSM in the stationary reference frame and uses two sliding mode (SM) observers to estimate the variables of interest: the states, the rotor position and the motor speed. A distinct advantage of the proposed approach is that speed is obtained algebraically - some previous speed estimation methods described in the state of the art use adaptation theory; however, this is usually not reliable. In the development, the motor voltages and currents are measured. A first SM observer estimates the EMFs of the PMSM model. Then, these are fed into a second SM observer which estimates the derivatives of the EMFs. The equivalent controls of the two observers are used to compute the speed. The paper discusses some of the approaches available to estimate the speed with known EMFs. The theoretical developments are supported with simulations.
    Power Electronics and Drive Systems (PEDS), 2013 IEEE 10th International Conference on; 01/2013
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    ABSTRACT: The sensorless vector control method for the high speed Permanent Magnet Synchronous Machine (PMSM) used as integrated starter-generator (ISG) applied in the microturbine generation system (MTG) is investigated in depth in this paper. For its characteristic of high rotating speed and low inductance, an improved open-loop back-EMF estimation method is proposed to estimate the position and velocity of the high speed PMSM. The tracking differentiator is used instead of the classic differentiator to overcome the problem of noise amplification. The variable parameter low-pass filter optimized based on the velocity is adopted to filter the estimated back-EMF. Moreover, the estimation errors caused by the low-pass filter and sampling delay are also compensated. The effects of voltage distortion caused by dead time on the estimation accuracy are weakened by dead-time compensation. Based on the proceeding estimation, the sensorless vector control system for the high speed PMSM used in a 30 kW MTG is designed and implemented. The simulation and experimental results show the proposed sensorless vector control method is simple, practical and possessing good estimation accuracy at large-scale speeds. It can satisfy the requirements in terms of fast and stability during the operation of microtubine generation system, and ensure that the system has good static and dynamic performance.