Switched reluctance motor drives are one of the most promising alternatives of ac induction and permanent magnet synchronous motor drives. The structure of a switched reluctance motor is shown below. Charged evs a closer look at switched reluctance motors. Switched reluctance motor aims to disrupt the market. Unlike common brushed dc motor types, power is delivered to windings in the stator case rather than the rotor. 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.
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. 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. The force tends to align the specimen of the material in such a. The stator and the rotor of the motor are aligned in such a way that the magnetic reluctance is minimum. 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. In this chapter we are going to discuss about the construction and working principle of the reluctance motor. Isbn 97895352677, eisbn 97895352684, pdf isbn 9789535147848, published 20170621. Electrical drives structure of electric power plants. With continued research, different topologies have emerged presenting less torque ripple, high efficiency, high. If the rotor bar 5, 6, 11, 12,17,18,23 and 24 are cut, it is similar to 4 salient poles. A variation on the conventional reluctance machine has been developed and is known as the switched reluctance sr machine.
The simulation results really report the work status of srm and validate the applicability of the nonlinear model for the switched reluctance motor. Characteristics and work principles of switched reluctance. For their operation the excitation unit which is controlled in accordance with. In this chapter, various srm topologies, design, principle of operation, and. A variable reluctance motor intended to move in discrete steps, stop, and start is a variable reluctance stepper motor. Switched reluctance motor srm controller and driver. Design of linear switched reluctance motor driver for. Smcs switched reluctance motor is changing the game. The switched reluctance motor srm is a type of a stepper motor, an electric motor that runs by reluctance torque.
The torque ripple is an inherent drawback of switched reluctance motor drives. Switched reluctance motorgenerator technology kaskod. Simulation and testing of a switched reluctance motor by. The torque production in switched reluctance motor comes from the tendency of the rotor poles to align with the excited stator poles. Reluctance motors operate on the principle that forces are established that tend to cause iron poles carrying a magnetic flux to align with each. Smc designed a mechanically leaner, switched reluctance motor and developed intelligent software to control it, making the motor inherently more efficient and reliable. Switched reluctance motor drives enables both students and engineers to learn all aspects of srm drive systems and appreciate the interdependence of the various subsystems in performance optimization. Characteristics and work principles of switched reluctance sr motor photo credit. Switched reluctance generators in contrast to wellknown conventional generators switched reluctance generator srg have toothed stator and rotor, and have neither windings nor permanent magnets in the rotor. The switched reluctance motor srm has both salient pole stator and rotor like a variable reluctance stepper motor.
Performance analysis of four phase 86 switched reluctance. Pdf controlling of switched reluctance motor drives. A reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on the ferromagnetic rotor. This is the basic working principle of switched reluctance motor or variable reluctance motor. The switched reluctance machine srm is the least expensive electrical machine to produce, yet one of the most reliable. The switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque. Switched reluctance motor construction and working. There are two types of the variable reluctance stepper motor. Figure 3 shows the current and voltage values for motor operation with 20 kw and reactive power compensation at the same time. Switchedreluctance sr motor concept has been known since 1838. The reluctance motor has basically two main parts called stator and rotor. There are no windings or permanent magnets on the rotor. 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. Torque is generated through the phenomenon of magnetic reluctance.
Here we will discuss construction and working principle of reluctance motor. Switched reluctance motor aims to disrupt the market 27 february, 2018 a californian company has developed a new form of highefficiency switched reluctance motor which, it claims, will dramatically improve the performance of hvac, refrigeration, pumping and other applications. International journal of information and electronics engineering, vol. Switched reluctance motor for electric vehicles blog. The srm has wound field coils as in a dc motor for the stator windings. Variable reluctance stepper motor its working circuit. Let us consider that the rotor of the squirrel cage induction motor consists of 24 copper bars.
We know about different types of synchronous motors, apart from all these motor works based on reluctance. Here is a view of a synrm synchronous reluctance motor in order to understand the working principle of such motor, you should realise that the synrm rotor has neither a conducting short circuit cageas the im doesnor permanent magnets or field. It has wound field coils of a dc motor for its stator windings and has no coils or magnets on its rotor. As such, research has blossomed during the last decade, and the srm and variable drive systems using srms are receiving considerable attention from industry. Switched reluctance motor for electrical drives offor electrical drives electric power plants equipment vladimir kuzmichev mpeitu, orgres. The switched reluctance machine was the first electric motor to have been designed but until the recent two decades hasnt been successfully implemented. Other articles where reluctance motor is discussed. Pdf position sensing system for switched reluctance. More the air gap, more is the reluctance and viceversa. Reluctance motor a single phase synchronous reluctance motor is basically the same as the single cage type induction motor. Commutating switched reluctance motors with pmac 3 phase referencing as a synchronous motor, the phase position information for an sr motor must have an absolute reference. The stator and rotor in a sr motor have salient poles. The stator of the motor has the main and auxiliary winding.
The switched reluctance motor srm represents one of the oldest electric motor designs around. 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. The number of poles presence on the stator depends on the number of phases the motor is designed to operate in. A stepper motor is designed to make it suitable for open loop position and. In switched reluctance motor applications both energy and cost efficiency play integral roles. Top quality motor control and motor drive solutions from infineons wide portfolio are the ideal choice. Reluctance motor subtypes include synchronous, variable, switched and. But single winding can not produce rotating magnetic. Development strategy of rao ues russia main purposes and stages of the project. As the rotor rotates, the inductance of the phase windings of a machine varies between the inductance values with respect to. The stator of the single phase reluctance and induction motor are same. 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 the switched reluctance motor srm is a type of motor doubly salient with phase coils mounted around diametrically opposite stator poles. Switched reluctance motorthe switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque.
The stator and rotor of a switched reluctance motor have salient poles. The rotor has neither windings nor permanent magnets. The torque production in the switched reluctance motor is explained using the. The fundamental operating principle of an srm is based on the higher. Cross section of a three phase switched reluctance motor srm, unaligned rotor position3 figure 2. But the lack of semiconductors to rapidly switch current on and off and a limited supply of engineers with the technical knowledge. This does not mean that an absolute position sensor must be used. Switched reluctance motor srm is gaining much interest in. If smooth rotation is the goal, there is an electronicdriven version of the switched reluctance motor. Unlike a conventional synchronous motor, both the rotor. Switched reluctance motors are also named as electronically commutated machines. Switched reluctance motor concept, control and applications. The rotor is basically a piece of laminated steel and its shape forms salient poles. Therefore, the effect of mutual coupling should be analyzed to decide whether it is negligible or not.
The reluctance motor is a type of synchronous machine. Advances in theory, computer design tools, and lowcost embedded systems. Switched reluctance sr motor is a brushless ac motor. Cross section of a three phase switched reluctance motor srm, unaligned rotor position4. The causes of the torque ripple include the geometric structure including doubly salient motor, excitation windings concentrated around the stator poles and the working modes which are necessity of magnetic saturation in order to. Switched reluctance motor srm is electromagnetic and electrodynamics. Reluctance motors can deliver high power density at low cost, making them attractive for many. The stator consists of a single winding called main winding. Variable reluctance motors or steppers actually use rotors like those in figure below. The reasons deal primarily with controller and power switching components.
The recent demand for variablespeed drives and primarily as a result of the development of power semiconductors, a variation on the conventional reluctance machine has been developed and is. Switched reluctance motor drives modeling, simulation. It has simple mechanical construction and does not require permanent magnet for its operation. And international journal of mechanical and production engineering, issn. The working principle of variable reluctance motor variable reluctance motors. Switched reluctance motors srm are seeing a resurgence as motor. Principle of operation of switched reluctance motor. This is a 4phase machine with 4 stator pole pairs and 3 rotorpole pairs 86 motor. You benefit from proven reliability and excellent figures of merit along with. The companys patented and awardwinning system has been tested in labs and the field and found to boost efficiencyreducing hvac energy use by up to 50% when compared to. Set to 64 default to specify a threephase 64 motor set to 86 to specify a fourphase 86 motor set to 108 to specify a fivephase 108 motor set to 64 60 kw preset model, 86 75 kw preset model, or 108 10 kw preset model to use a predetermined specific model of a switched reluctance motor. Model the dynamics of switched reluctance motor simulink. Constructional features rotary and linear srm principle of operation torque.
In the light of above it is a competitive motor variable speed dc motor and variable speed 3 phase cage induction motor. When you use these presets, you do not need to specify the parameters in the. One form of reluctance motor is shown in cross section in the figure. By switching the phases, the rotor moves stepwise, therefore this principle is also used for small reluctance stepper motors, but then without a position sensor to. The stator poles have concentrated winding rather than sinusoidal winding. Switched reluctance motor for electrical drives offor. It generates torque through magnetic reluctance reluctance motor subtypes include synchronous, variable, switched and variable stepping. The operation principle is based on the difference in magnetic reluctance for magnetic field lines between aligned and unaligned rotor position.
412 515 1124 392 1459 394 1265 1131 1391 1342 814 1209 622 384 1239 839 864 906 471 263 4 128 68 534 1134 1300 653 1118 1386 1586 725 691 379 1360 808 356 548 268 1323 885 893 115 511 1284 1028 885