If the inline pdf is not rendering correctly, you can download the pdf file here. Aim and scope of the project the aim of the project is to design a real synchronous switched reluctance motor and analyze how the key parameters, some of which are great indicators of the good performance of the motor. Due to double saliency structure of switched reluctance motor srm torque ripple is high, which causes vibration and noise. Simulation of switched reluctance motor and control based on matlab environment 3 chapter 2 2. Electric drives brushless dc ac and reluctance motors. Sr motors require precise control to optimise the operating efficiency. Torque equation of synchronous reluctance motor youtube. Chandur sadarangani royal institute of technology department of electrical engineering electrical machines and power electronics stockholm 2007. Synchronous reluctance machine synrm design by reza rajabi moghaddam master thesis supervisor. In the case of the simple dc circuit current, voltage and resistance are related to each other, under steadystate conditions, in accordance with ohms law. In the srm, both the stator and rotor have a structure of salient pole, which contributes to produce a high output torque. It generates torque through magnetic reluctance reluctance motor subtypes include synchronous, variable, switched and variable stepping. A reluctance motor torque is produced due to the tendency of the rotor to align itself in the minimum reluctance position, when the speed of the motor is close to the synchronous speed. An external magnetic field induces an internal magnetic field in the object and because of this torque is produced.
Because the reluctance along the path of the magnet flux is minimized when the magnet is as close as possible to in contact with the. It is a 6pole sinusoidal synchronous reluctance motor srm. In order to enhance and increase torque density of pure. Reluctance motors can deliver high power density at low cost, making them. Analytical method of torque calculation for interior. First strategy is to develop the inner torque loop to generate current reference in order to minimize the torque ripple. What is the difference between synchronous reluctance. Pdf in this paper, torque characteristics analysis of synchronous reluctance motor with the cylindrical rotor type by winding function theorywft is. The above conventional method is not simple and is based on the fundamental component of the airgap flux. Reluctance in a magnetic circuit is analogous to resistance in electric circuit. It shows the torque ripple for a rotation of an electrical angle of 15 equal to a mechanical angle of 5, sixpole motor.
In this model of machine, both stator as well as rotor is assumed to be salient pole type. In this case if y windings are energized, stator will move towards right side as a carrier. The analysis is performed to estimate the influence of the number of stator slots and nonmagnetic areas in the rotor i. Pmsm permanent magnet synchronous machines pmsm have of course permanent magnets in their rotor.
The torque ripple can be minimized by a novel control technique called direct torque. Reluctance motors can deliver high power density at. The variable reluctance motor is based on the principle that an unrestrained piece of iron will move to complete a magnetic flux path with minimum reluctance, the magnetic analog of electrical resistance. The following figure shows the ideal waveforms phase a inductance and current in a 64 srm. A simple application of this principle is the refrigerator magnet, which is held in place by reluctance force. Optimisation of an 80kw segmental rotor switched reluctance. In chapter 9 we explained that reluctance torque referred to the natural tendency of the projecting poles on a rotor without any windings or magnets to align. As mentioned previously, the magnetic circuit is similar in some respects to the electric circuit. Jul 12, 2017 special electrical machines, torque equation of syrm,electrical machines, electrical engineering, dc motor,dc generator, emf equation, advanced electrical machines, reluctance torque, reluctance. Static simulation of a 128 switched reluctance machine.
Reluctance torque analysis and reactance calculation of ipm for. The structure of reluctance motor is same as that of salient pole synchronous machine as shown in fig. Lets us consider a doubly excited magnetic system as shown in figure below. Design of linear switched reluctance motor driver for. Reluctance torque is the torque generated because the motor is moving to a position where the reluctance seen by the armature flux is declining. The switched reluctance motor srm is an electric motor which operates on reluctance torque. The variable reluctance motor is based on the principle that an unrestrained piece of iron will move to complete a magnetic flux path with minimum reluctance, the magnetic analog of electrical resistance synchronous reluctance. Request pdf torque control of switched reluctance motors this paper presents the performance of an instantaneous torque control method. Electric motors create mechanical motion by taking advantage of electromagnetism and basic electrical principles, and they make up the vast majority of commercial motors today. This additional current owing through the stator results in more loss and thereby lower the permanent magnetassisted synchronous reluctance motor pmasynrm was designed to provide the. Introduction in earlier stage of automatic doors developments, rotary dc motor which has a high torque was preferred for horizontal movement of door. There are so many different types of electric motors that it can be difficult to determine which one is right for your application. It is like the resistance offered to the magnetic flux lines by the medium.
Reluctance motor subtypes include synchronous, variable, switched and variable stepping. Synchronous reluctance motor, sensitivity analysis, main parameter, transversally. If the rotating field of a large synchronous motor with salient poles is deenergized, it will still develop 10 or 15% of synchronous torque. Magnetic reluctance, or magnetic resistance, is a concept used in the analysis of magnetic circuits. With continued research, different topologies have emerged presenting less torque ripple, high efficiency, high. The following figure shows the ideal waveforms phase a. Matlab simulink implementation of switched reluctance motor. It works on the same principle as for stepper motor. Study of the synchronous reluctance motor design in.
Thus finally the reluctance motor runs as a synchronous motor. The resistance of the rotor must be very small and the combined inertia of the rotor and the load should be small to run the motor as a synchronous motor. Impact of the external rotor configuration on the electromagnetic torque and torque ripple is analysed. The placement of the stator windings to linear switched reluctance motor. Torque prediction using the fluxmmf diagram in ac, dc, and reluctance motors article pdf available in ieee transactions on industry applications 321. Switched reluctance motor open model this example shows a currentcontrolled 60kw 64 srm drive using the srm specific model based on measured magnetization curves. Design of lowtorqueripple synchronous reluctance motor.
With continued research, different topologies have emerged presenting less torque ripple, high. Pdf torque prediction using the fluxmmf diagram in ac, dc. The simulation and experimental results illustrate the capability of. Electric drives brushless dc ac and reluctance motors description and applications brushless motors. Magnetic reluctance in a magnetic circuit is analogous to. Reluctance torque is created due to the saliency of the rotor. This is similar to the force between a magnet and a steel bar. If load is excessive motor may not pull into synchronism and if already running it may pull out of synchronism. The electromagnetic torque which is obtained from the motor is taken to get the current reference from the relation t. Design of lowtorqueripple synchronous reluctance motor with external rotor. Model the dynamics of switched reluctance motor simulink.
Unit 1 synchronous reluctance motors constructional. Development strategy of rao ues russia main purposes and stages of the project. Optimum design and operation analysis of permanent magnet. Anju and rajasekaran design and performance analysis of high speed switched reluctance motor drive for various industrial applications electromagnetic torque developed by variable reluctance motor is given by t. Design of a reluctance synchronous machine for traction motor applications using the finite element method jarrad g. Lets assume that stator is energized from source vs whereas rotor is energized with source vr. If a movement to the other side is desired, z windings should be energized. Torque ripple is also minimized to a practically acceptable. Firstly, the torquepower angle characteristic curve of selected synchronous motor is calculated in fem.
Analytical design of a synchronous reluctance motor srm. Pdf torque characteristics analysis of synchronous reluctance. Wright a dissertation submitted to the faculty of engineering and the built environment. This optimization is mainly focused on the torque maximization for a certain current.
Switched reluctance motor for electrical drives offor electrical drives electric power plants equipment vladimir kuzmichev mpeitu, orgres. It is defined as the ratio of magnetomotive force mmf to magnetic flux. Simulation and testing of a switched reluctance motor. The main dimensions of the test motor are shown in table 1. Reluctance torque reluctance torque or alignment torque is experienced by a ferromagnetic object placed in an external magnetic field, which causes the object to line up with the external magnetic field. But induction motor im was become widespread by reason of high maintenance. Electrical drives structure of electric power plants. The resistance of the rotor must be very small and the combined inertia of the rotor. Brushless motors such as permanent magnet and switched reluctance motors depend on electronic drive systems which produce rotating magnetic fields to pull the rotors around. This type of machine is a doubly salient structure having projecting poles on both the stator and the rotor. Total torque developed in such doubly excited magnetic. Anju and rajasekaran design and performance analysis of high speed switched reluctance motor drive for various industrial applications fig. Reluctance torque an overview sciencedirect topics.
Permanent magnet assisted synchronous reluctance motor. This paper presents the performance of an instantaneous torque control method. This is the angle of skewing of the rotor adopted to reduce torque ripple. And the control strategies commonly used in this srd are main. Simulation and testing of a switched reluctance motor by matlab simulink and dspace master of science thesis in electric power engineering saman abbasian. Dtc of switched reluctance motor drive using simplified torque equation p. In these examples we will assume that the reluctance of the. Synchronous reluctance motors synrms have become prominent since.
Analytical design of a synchronous reluctance motor srm pag. The starting torque of the reluctance motor is dependent upon position of rotor because the rotor is a salient pole one. Matlab simulink implementation of switched reluctance. Read permanent magnet synchronous motors using primarily reluctance torque, electrical engineering in japan on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Based on the curve we can calculate the ratio of reluctance. Inductance in terms of magnetic reluctance and magnetic permeance. Simulation and testing of a switched reluctance motor by. Reluctance torque has traditionally been exploited together with excitation torque in large hydrogenerators. To develop positive torque, the currents in the phases of a srm must be to the rotor position.
Basically the synchronous reluctance motor is a true ac rotating field machine, requiring a balanced polyphase sinusoidal supply into a distributed winding, which for all intents and purposes is identical to that of the induction machine of the same power rating. Special electrical machines, torque equation of syrm,electrical machines, electrical engineering, dc motor,dc generator, emf equation, advanced electrical machines, reluctance torque, reluctance. The value of starting torque lies between 300 to 400 percent of its full load torque. Basically its kind of a stepper motor which rotates. Index termslinear switched reluctance motor, linear motor driver, automatic door. They are compact, powerful and offer excellent dynamic response. Design and performance analysis of high speed switched. Reluctance torque or alignment torque is experienced by a ferromagnetic object placed in an external magnetic field, which causes the object to line up with the external magnetic field. Brushless motors such as permanent magnet and switched reluctance motors depend on electronic drive systems which produce rotating magnetic fields to. Pdf maximum torque control of a sensorless synchronous. Matlab simulink implementation of switched reluctance motor with direct torque control technique vikramarajan jambulingam electrical and electronics engineering, vit university, india. Sr motor principle and related torque general equation. Reluctance torque, also known as aligment torque, is due to the forces that occur when a magnetic material interacts with a magnetic field.
The paper focuses on studying the externalrotor synchronous reluctance motor. Thus we see that even though stator current is zero, an electromagnetic torque is developed as the reluctance seen by the rotor produced flux changes with the position of rotor o r in view of the above two cases, we can say that the torque expressions as obtained in two cases are reluctance torque as. Another class of machine, which has been relatively ignored, is synchronous reluctance machines. A reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on the ferromagnetic rotor. This machine is characterized by a high starting torque and effici ency similar to a high ef ficiency im. Synchronous reluctance motordrive package for machine. The operation of reluctance motor with diagram a media to. The paper presents new designs for synchronous reluctance motors that have external rotor segmentshaped rotor, rotor with additional nonmagnetic space to the quadrature axis of the rotor, and rotor with several flux barriers. Dsp based simulator for speed control of the synchronous. Pdf the algorithmic structure of a vector controller capable of high quality speed control of a synchronous reluctance motor with and without the use. A switched reluctance motor is an electric motor in which the torque is produced by the tendency of its moveable part to move to a position of least reluctance, which corresponds to the position of maximum inductance miller 1993.
It represents the opposition to magnetic flux, and depends on the geometry and composition of an object. Rashad3, senior member ieee 1department of electrical energy, systems. Permanentmagnet, reluctance, and induction motors compared it is possible to find superefficient highhorsepower motors. Switched reluctance motor for electrical drives offor. Ibrahim1,2, student member ieee, peter sergeant1, member ieee,ande.
The motor operates at a constant speed upto a little over 200% of its full load torque. The animation below shows how tha air gap flux density changes with rotor position and plot the normalized torque at each. All about reluctance motors what they are and how they work. Switched reluctance motor srm is gaining much interest in industrial applications such as wind energy systems and electric vehicles due to its simple and rugged construction, high. Pdf torque prediction using the fluxmmf diagram in ac. Parts of the switched synchronous reluctance motor srm the srm is constituted by the rotor and the stator. Electromagnetic torque ripple factor is calculated for each studied motor using the results of magnetic field numerical calculations. Reluctance torque is exclusively used in sycnhronous reluctance and switched reluctance machines, and is a significant component of the torque in interior permanent magnet machines, which are commonly found in electric drivetrains for. The advantages of adding pms to the syn chronous reluctance motor rotor construction are the increased motor power factor and thus reduced motor stator ohmic. The load inertia should be within the limits, for proper effectiveness. Wright a dissertation submitted to the faculty of engineering and the built environment, university of the witwatersrand, johannesburg, in ful. National institute of technology rourkela certificate this is to certify that the thesis entitled direct torque control of switched reluctance motor drives submitted by. Torque control of switched reluctance motors request pdf.