Modelling of permanent magnet synchronous motors (original) (raw)
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Review of Position Estimation Methods for Permanent Magnet Synchronous Motors
This paper presents a review regarding the techniques used for estimation of position and speed of sensorless permanent magnet synchronous motor drives .Permanent-magnet synchronous machines (PMSMs) are widely used in industrial applications due to their distinctive advantages, such as high efficiency, high power density, and wide constant power region. Most of the times, accurate rotor position information is measured by rotary encoders or resolvers to achieve high-performance field oriented control. However, the use of these sensors increases the cost, size, weight, and wiring complexity and reduces the mechanical robustness and the reliability of the overall PMSM drive systems. Hence sensoreless methods have gained much attention. In this Paper Sensoreless Control Methods including Indirect Methods based on magnitude of back EMF, some model based methods like Flux linkage based estimation, Non-linear observers and extended kalman filter and high frequency signal injection based methods are described.
2018
This thesis provides a study for the rotor position estimation in SM-PMSMs, particularly at zero and low speeds. The method for zero rotor speed is based on injection of three high frequency voltage pulses in the motor stator windings. Then, the voltage responses at the motor terminals are exploited to extract the rotor position. Two approaches, modelling and practical implementations, are presented. The obtained results have showed a verification of a high-resolution position estimation (a position estimation of 1 degree angle), a simplicity and cost effective implementation and a no need for current sensors is required to achieve the estimation process. It should be noticed that the implementation of rotor position estimation at zero speed is only attended when the rotor is at standstill or very low speed. Therefore, the motor driver is not expected to be active at this condition. Thereby, the zero speed estimation does not provide a robust torque control. In future, this should b...
2012 XXth International Conference on Electrical Machines, 2012
Sensorless control of Permanent-Magnet Synchronous Motors (PMSM) at low velocity remains a challenging task. A now well-established method consists in injecting a highfrequency signal and use the rotor saliency, both geometric and magnetic-saturation induced. This paper proposes a clear and original analysis based on second-order averaging of how to recover the position information from signal injection; this analysis blends well with a general model of magnetic saturation. It also proposes a simple parametric model of the saturated PMSM, based on an energy function which simply encompasses saturation and cross-saturation effects. Experimental results on a surface-mounted PMSM and an interior magnet PMSM illustrate the relevance of the approach.
Analytical models for exterior-type permanent magnet synchronous motors
IEEE Transactions on Magnetics, 1987
i n h i g h e n e r g y p e r m a n e n t m a g n e t m a t e r i a l s and power e l e c t r o n i c s have widely enhanced t h e a p p l i c a t i o n s of Permanent Magnet (P.M.) synchronous motors i n v a r i a b l e s p e e d d r i v e s and robotic systems. Determination of e q u i v a l e n t c i r c u i t p a r a m e t e r s i s of c r i t i c a l i m p o r t a n c e f o r t h e performance prodiction of such motors. The purpose oE t h i s p a p e r i s to develop magnetic and i t s dual e l e c t r i c e q u i v a l e n t c t r c u i t model of P.M. synchronous m o t o r s w i t h s u r f a c e m o u n t e d r a d i a l a n d c i r c u m f e r e n t i a l l y o r i e n t e d NdBFe magnets in the rotor a s s e m b l y . S i m p l i f i e d a n a l y t i c a l e x p r e s s i o n s f o r b o t h t h e d i r e c t and quadrature axis parameters are provided taking into account the modified Carter's co-efficient and saturation eEfects. Experimental res:llts a r e p r e s e n t e d t o v e r i f y t h e a n a l y t i c a l models. There e x i t s a reasonably close agreement between the measured and predicted reactance parameter values. TNl'JODUCTION Recent developments of high energy permanent m a g n e t m a t e r i a l s l i k e Neodymium-Boron-Iron NdBFe have opened up new p o s s i b i l i t i e s f o r t h e l a r g e s c a l e a p p l i c a t i o n s of P.M. motors i n v a r i a b l e s p e e d d r i v e s , p o s i t i o n c o n t r o l and robotic systems. The design a n a l y s i s of P.M. m a t e r i a l s i n t h e p o l e s t r u c t u r e s of conventional dc motors 1s a l r e a d y w e l l e s t a b l i s h e d [ l ] . The a p p l i c a t i o n s of permanent magnets tn small s i z e g e n e r a t o r s , a i r c r a f t a l t e r n a t o r s and p i l o t e x c i t e r s f o r l a r g e g e n e r a t o r s a r e q u i t e w e l l known [ 2 ] . However, the design and analysis of permanent magnet synchronous motors a r e g e t t i n g i n c r e a s i n g l y wide attentLon recently. I n P.M. synchronous motors, t h e r e a r e b a s i c a l l y two types of permanent magnet r o t o r s v i z . , i n t e r L o r and exterior assembly of magnets. In t h e i n t e r i o r -t y p e [ 3 ] , a conductton squirrel-cage design i s employed with the magnets embedded i n s i d e t h e r o t o r i r o n l a m i n a t i o n . It i s o p e r a t e d u s u a l l y a t mains voltage and line frequency of 60 Hz. The squirrel-cage windings are necessary f o r smooth s t a r t , a c c e l e r a t i o n and synchronization of t h e c o n n e c t e d i n e r t i a l o a d . The i n t e r i o r magnets a r e n a t u r a l l y p r o t e c t e d a g a i n s t d e m a g n e t i z a t i o n d u r i n g s t a r t i n g and s h o r t -c i r c u i t c o n d i t i o n s . In t h e e x t e r i o r -t y p e d e s i g n , r a d i a l l y o r c i r c a i l~~e r e n t i a l l y d i r e c t e d permanent magnets having high co-ercive Force a r e f i x e d t o t h e o u t e r s u r f a c e of t h e i r o 3 r o t o r . This design eliminates the loss of magnet f l u x which occurs with the embedded magnets. This motor f i t t e d with a s h a f t p o s i t i o n e n c o d e r p r o v i d e s i n v e r t e r f r e q u e n c y c o n t r o l s u c h t h a t t h e r o t o r i s i n synchronLsm a t a l l v a l u e s of speed. Asynchronous s t a r t l n g a n d s y n c h r o n i z a i n g c a p a b i l i t y a r e b u i l t -i n i n t h e i n v e r t e r c o n t r o l ; and t h e r e f o r e t h e s q u i r r e l -c a g e winding can be dispersed with. These electrorlic.ll.ly commutated e x t e r i o r -t y p e P.M. synchronous motors have i d e a l p e r f o r m a n c e c h a r a c t e r i s t i c s of dc motocx g l t h o u t mechanical commutators and brush-gear assembly. It is a l s o c a l l e d a b r u s h l e s s dc motor.
Permanent Magnet Synchronous Motor(PMSM) drives are being used increasingly in a wide range of applications, such as machine tools, robotics, aerospace generators, actuators and electric vehicles. It is extensively used in industrial applications due to it's advantageous features such as high efficiency, high torque to inertia ratio, low noise and robustness. In advanced motor control system, an accurate knowledge of motor parameters is essential in order to achieve a better performance. Machine parameters are classified into electrical parameters such as resistances of windings and d, q axes inductances of both stator and rotor and mechanical parameters such as angular position, speed, moment of inertia and viscous friction coefficient. Various types of parameters estimation methods for PMSM are available in the literature such as back e.m.f. based method, signal injection based method, state observer based method, model reference adaptive system (MRAS) based method etc. This paper presents a review of all these methods used to estimate the parameters of a Permanent Magnet Synchronous Motor.
Permanent-magnet synchronous machines
AccessScience
Interest in permanent magnet synchronous machines (PMSMs) is continuously increasing worldwide, especially with the increased use of renewable energy and electrification of transports. This special issue contains the successful invited submissions of fifteen papers to a Special Issue of Energies on the subject area of "Permanent Magnet Synchronous Machines". The focus is on permanent magnet synchronous machines and the electrical systems they are connected to. The presented work represents a wide range of areas. Studies of control systems, both for permanent magnet synchronous machines and for brushless DC motors, are presented and experimentally verified. Design studies of generators for wind power, wave power and hydro power are presented. Finite element method simulations and analytical design methods are used. The presented studies represent several of the different research fields on permanent magnet machines and electric drives.
Effect of Rotor Geometry and Magnetic Saturation in Sensorless Control of PM Synchronous Machines
IEEE Transactions on Magnetics, 2000
Sensorless control of permanent-magnet synchronous machines (PMSMs) at low speed and standstill is often based on a difference between-and-axis inductances. By determining the inductances, i.e., by evaluating current responses that result from the supply of voltage test vectors, an estimation of the rotor position is obtained. These inductances are dependent on the stator current-because of (cross-)saturation-and on the geometry of the PMSM. Changing inductances strongly affect the accuracy of the rotor position estimation. This paper investigates the influence of geometrical parameters of the rotor on the inductances and on the position estimation. First, for several angles, widths, heights, and radial positions of the buried magnets in the rotor, finite element models (FEMs) calculate the inductances and the torque as a function of the stator current. Second, to study the effect of the variable-and-inductances on the position estimator, time-domain simulations are carried out in combination with FEM evaluations. The simulated control is validated on an experimental interior PMSM. The FEM is not needed by the controller in the experiments.