Sr motor principle and related torque general equation. Reluctance motor technical seminar report annual year 2014, electrical and electronics department, sdmt, ujire574240 page 3 reluctance motors are subjected to cogging at the time of starting. The operation is based on various reluctance positions of rotor with respect to t when any one phase of the stator is excited, it produces its magnetic field whose axis i along the poles, the phase around which is excited. I recently heard something that made me do a little research into switched reluctance motors. Model the dynamics of switched reluctance motor simulink. Rotor design of linestart synchronous reluctance motor to improve starting performance seunghyoung ha1, jungpyo hong1, jiyoung lee1, hyuk nam2, gyuhong kang3 dept. The working principle of variable reluctance motor. The stator and rotor in a sr motor have salient poles. 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. The stator of the single phase reluctance and induction motor are same. Reluctance motors operate on the principle that forces are established that tend to cause iron poles carrying a magnetic flux to align with each.
We know about different types of synchronous motors, apart from all these motor works based on reluctance. Simulation and testing of a switched reluctance motor by matlab simulink and dspace saman abbasian department of energy and environment faculty of electric power engineering chalmers university of technology the main objective of this thesis is to build and test a srm drive system to provide a research platform. May 15, 2017 the switched reluctance motor srm is a type of a stepper motor, an electric motor that runs by reluctance torque. This design is known as a 64 sr motor, and operates with 3 phases. Sr motors are special type of variable reluctance motor designed for continuous operation. The theory of synchronous reluctance machine was established the first time in this paper. The rotor is basically a piece of laminated steel and its shape forms. National institute of technology rourkela certificate this is to certify that the thesis entitled direct torque control of switched reluctance motor drives submitted by amalendu dash. Switched reluctance sr motor is a brushless ac motor. Rotor design of linestart synchronous reluctance motor to. This thesis presents a design method for a switched reluctance sr motor to optimise torque production for two types of 3 phase 64 poles srm and 86 poles srm designs. The current in the phase winding is the result of logical and ing of the rotor position sensor and chopping frequency.
There are no windings or permanent magnets on the rotor. Characteristics and work principles of switched reluctance sr motor photo credit. The srm has wound field coils as in a dc motor for the stator windings. Switched reluctance motor open model this example shows a currentcontrolled 60kw 64 srm drive using the srm specific model based on measured magnetization curves. A diagram of a switched reluctance motor is shown in fig. The text that was researched and compiled contains explanations of the motor parts, theory about electromagnetism and how current is used to. The operation of reluctance motor with diagram blogger. The stator of the motor has the main and auxiliary winding.
The principle and insight of the proposed single winding scheme and its. It describes the comparison results and the performance. This greatly simplifies mechanical design as power does not have to be delivered to a moving part, but it complicates the. The theory used in the work was collected by studying literature on how electrical motors work, and by simplifying the explanations to suit the intended reader. Motor runs at slip speed reluctance torque, trel reluctance torque, trel maximum reluctance torque, trelmax occurs at. How could drives soon make switchedreluctance motors more common. In this configuration, a 3phase sr motor has 6 stator poles.
Choi national aeronautics and space administration glenn research center cleveland, ohio 445 mark siebert university of toledo toledo, ohio 43606 a 128 switchedreluctance motor ref. It sounds like theyd be perfect for something like electric cars, since they are slightly more efficient than ac induction, and can be cooled more easily. Reluctance motors can deliver high power density at low cost, making them attractive for many. An important point can be seen in the motor diagram. And, unlike induction motors that can stop working when one of its phases drops out, the smc motor continues operating because its intelligence automatically takes control and. If smooth rotation is the goal, there is an electronicdriven version of the switched reluctance motor. Magnetfree motor technology for fixed speed applications reaching. A reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on the ferromagnetic rotor. Switched reluctance motor for electric vehicles blog. Switched reluctance motor srm the switched reluctance motor srm is a type of motor doubly salient with phase coils mounted around diametrically opposite stator poles.
Reluctance motor subtypes include synchronous, variable, switched and variable stepping. Unlike a conventional synchronous motor, both the rotor and stator of a switched reluctance motor have salient poles. Unlike common dc motor types, power is delivered to windings in the stator case. 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. A bearingless switchedreluctance motor for high specific power applications benjamin b. As the major part of hev technologies, the electric motor drives have to offer high efficiency, high power density, high controllability, wide. One form of reluctance motor is shown in cross section in the figure. Jun 16, 2016 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. The rotor has neither windings nor permanent magnets. To develop positive torque, the currents in the phases of a srm must be to the rotor position. For more information on switchedreluctance motors pdf download university of technology, sydney. Switched reluctance motor drives for hybrid electric vehicles. Pdf switched reluctance motor drive with external rotor.
Reluctance motors can deliver high power density at. Switched reluctance motor for electrical drives offor. The load inertia should be within the limits, for proper effectiveness. When the rotor is out of alignment, the inductance is very low and the current also increase rapidly. The reluctance motor has basically two main parts called stator and rotor.
For the test drive, we selected the fluxcurrent method. Unit 1 synchronous reluctance motors constructional. There is no winding on rotor, this is the main feature of sr motor,for the common motor working principle, we know energized conductor in magnetic field drive and force the rotation of the motor. Smooth transition between optimal control modes in switch reluctance motor by badal patnaik 1001227260 sanjit debta 1001227317 d. Electric drives brushless dc and reluctance motors. Switched reluctance motor srm the switched reluctance motor was designed for use in high power, high efficiency, variable speed drives. The switched reluctance motor by software motor company smc is the led of motors, reducing hvac energy consumption by up to 50%. With continued research, different topologies have emerged presenting less torque ripple, high efficiency, high. Reluctance motor the reluctance motor has basically two main. The variable reluctance motor is an evolution of the stepping motor and is generally designed for use in low power, open loop position and speed control systems where efficiency is not of prime importance. To start with the switched reluctance motor, the torque production in the machine is explained with the help of principle of electromechanical energy produced in the coil of the machine. Switched reluctance motorswitched reluctance motor. Sr motors require precise control to optimise the operating efficiency.
With advanced fuel or diesel engines and variable speed technology. Switched reluctance motorswitched reluctance motor operation. Switched reluctance generators srg running the engine at variable speed and using power electronics to convert the variable frequency to a fixed voltage and frequency can allow more efficient operation of the genset. The switched reluctance motor srm is an electric motor which operates on reluctance torque. In this chapter we are going to discuss about the construction and working principle of the reluctance motor. 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. Switched reluctance motor srm, rotor position, sensorless method, flux linkage.
A 3phase sr motor with 6 stator poles and 4 rotor poles is also known as a 64 3phase sr motor. Jan 02, 2018 switched reluctance motor the switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque. In the simulation results, how the rotor minimizes the reluctance position during excitation in a magnetic circuit is presented in this work. Switched reluctance motor srm is an energy converter that converts an electrical energy to mechanical energy in motoring operation and viceversa in generating operation. The machines are structurally simple but can need relatively advanced control for.
Working principle of switched reluctance motor 20150305. Here we will discuss construction and working principle of reluctance motor. The external rotor core structure and the internal stator core. Jul 30, 2017 a reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on the ferromagnetic rotor. Introduction srm can be classified on the basis of the nature of motion. Reluctance motor a single phase synchronous reluctance motor is basically the same as the single cage type induction motor. These challenges are being overcome by advances in the theory, by the use. Advances in theory, computer design tools, and lowcost embedded systems for control.
A very good overview of sensorless methods for determining the rotor position of switched reluctance motors is given in ray. The stator has a laminated construction, made up of stampings. Synchronous reluctance motors process performance motors iec. The basic principle is that, in contrast to induction motor technology, these.
The rotor of a reluctance motor is a squirrel cage with some rotor teeth removed in the certain places to provide the desired number of. With asimmetrical magnetic system 3phase 124 srd 124 srm. It works on the same principle as for stepper motor. Principle of operation of switched reluctance motor engineering essay. Simulation and testing of a switched reluctance motor by. Torque and controllable radial force production in a single winding.
Cogging is the locking tendency of the rotor which can be minimized by skewing the rotor bars and not making the. Switched reluctance motors the structure of a switched reluctance motor is shown below. Summary switched reluctance motors have an innate characteristic of. Basically its kind of a stepper motor which rotates through a step angle when. It generates torque through magnetic reluctance reluctance motor subtypes include synchronous, variable, switched and variable stepping. Working principle of switched reluctance motor srm as we know that magnetic flux have a tendency to flow through lowest reluctance path, therefore rotor always tends to align along the minimum reluctance path. The structure of reluctance motor is same as that of salient pole synchronous. Torque is generated through the phenomenon of magnetic reluctance.
Variable reluctance motors or steppers actually use rotors like those in figure below. Principle of operation of switched reluctance motor. Since the variable reluctance motor has a high torque with the inertia ratio normal when compared with other motors. Switched reluctance motorthe switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque. Simulink and dspace saman abbasian department of energy and environment faculty of electric power engineering chalmers university of technology the main objective of this thesis is to build and test a srm drive system to provide a research platform. The operation of reluctance motor with diagram a media to. It has simple mechanical construction and does not require permanent magnet for its operation. This greatly simplifies mechanical design as power does not have to be delivered to a moving part, but it complicates the electrical design as some sort of switching system needs. Then rotor moves in such a direction as to achieve minimum reluctance position. This is the basic working principle of switched reluctance motor or variable reluctance motor. Characteristics and work principles of switched reluctance. The switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque. This paper presents the design procedure for three phase switched reluctance motor srm with two different cases case1.
A bearingless switchedreluctance motor for high specific. The switched reluctance motor srm is a type of a stepper motor, an electric motor that runs by reluctance torque. Gouri sankar 1001227269 debendra kido 1001227267 ananya subhadarsinee 1001227255 2. The following figure shows the ideal waveforms phase a inductance and current in a 64 srm. A reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on. Accurate torque and speed control for reliable extruder operation english pdf brochure. Properly designed sr motors are capable of high torques with low weight, making them attractive for vehicle and aerospace applications. Switched reluctance motor for electrical drives offor electrical drives electric power plants equipment vladimir kuzmichev mpeitu, orgres. Unlike common dc motor types, power is delivered to windings in the stator case rather than the rotor. As the rotor rotates, the inductance of the phase windings of a machine varies between the inductance. This paper describes the developed threephase 68 poles switched reluctance external rotor motor drive for a fan in air conditioner. Switched reluctance motor srm is an energy efficient machine which receives electrical energy from the power source and returns part of stored magnetic energy back to the supply, during each. In order to understand the working principle of such motor, you should realize that the sr rotor has neither a conducting short circuit cageas. The force tends to align the specimen of the material in such a.
With abb ie5 synrm motors you achieve ultrapremium efficiency. Switched reluctance motor construction and working. However, synrm was not an alternative to industrial. Apart from the working they have many advantages such as simple and low cost construction. The stator poles have concentrated winding rather than sinusoidal winding. The sr motor produces torque through the magnetic attraction which occurs between stator electromagnets and a corresponding set of salient poles formed on a simple rotor made only of ferromagnetic material. This doubly salient arrangement is very effective for electromagnetic energy conversion. Pdf design of switched reluctance motor with exterior. Unlike common dc motor types, power is delivered to. Switched reluctance motor control basic operation and example using the tms320f240.
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