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. Reluctance motors operate on the principle that forces are established that tend to cause iron poles carrying a magnetic flux to align with each. Synchronous motors contain multiphase ac electromagnets on the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line. Up to 94% efficiency, much more efficient than acim alternate current induction motor machine in all speed. Switched reluctance motors the structure of a switched reluctance motor is shown below. Where, n s synchronous speed, f supply frequency and p number of poles. The rotor has neither windings nor permanent magnets. The synchronous reluctance sr motors driven by variable speed inverters have been recently introduced in the industrial market. In fact, a given synchronous machine may be used, at least theoretically, as an alternator, when driven mechanically or as a motor, when driven electrically, just as in the case of d.
To calculate eddy current and hysteresis loss in the stator, i used the built in harmonic ac solver in femm 4. This is due to variable reluctance throughout a rotor revolution. The life of dc servo motor depends on the life on brush life. A synrm rotor has neither a conducting short circuit cage as with the im, nor permanent magnets, nor a field excitation winding. Synchronous reluctance motor electric motor rotating machines.
As we can see from the equation, the synchronous speed depends on the frequency of the supply and the number of poles. Pdf design of synchronous reluctance motor for hybrid. To save computation time, rather than calculating the ac losses for each simulation in the optimization, i solved for the losses in a simplified geometry a simple tube with 50 mm od, and 42 mm id, the same dimensions as the stator back iron over the entire space of frequencies and. Ie4 synrm motor and drive package induction motor on the outside, innovation inside synchronous reluctance motors combine innovative rotor and conventional stator technology. The threephase synchronous reluctance motor synrm is presented as a possible alternative in allelectric ship applications. Synchronous reluctance motordrive package for industrial use. Construction and principles of operation the slosyn motor is unique in that it has the capability of being operated as an ac synchronous, constant speed motor or as a phase switched dc stepper motor.
Here we will discuss construction and working principle of reluctance motor. 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. Of synchronous machines the synchronous electrical generator also called alternator belongs to the family of electric rotating machines. Synchronous motor having no load connected to its shaft is used for power factor improvement. Design of synchronous reluctance motor for hybrid electric vehicles conference paper pdf available in ieee transactions on industry applications 514. It generates torque through magnetic reluctance reluctance motor subtypes include synchronous, variable, switched and variable stepping. Synchronous machines 6 where w is the angular frequency of emf in electrical radians per second and wm the angular speed of the rotor in mechanical radians per second. Permanent magnet assisted synchronous reluctance motor design and performance improvement. The operation of the synchronous induction motor is explored in this video.
Synchronous reluctance motors process performance motors. Let the rotor also produces two poles when they are excited by the external dc source. This is the basic working principle of switched reluctance motor or variable reluctance motor. Thus finally the reluctance motor runs as a synchronous motor. Synchronous reluctance machine design 1 1 introduction the purpose of this report is to present information necessary for developing a suitable synchronous reluctance motor synrm rotor geometry design procedure. Reluctance motor subtypes include synchronous, variable, switched and variable stepping. Contrast this with an induction motor, which must slip in order to produce torque. Simulation and testing of a switched reluctance motor by. Switched reluctance motor construction and working. This is the basic constructional difference between a brushless motor and a typical dc motor.
The two primary components of a reluctance motor are the outer stationary stator and the inner rotor, separated by. Instead, the magnetic principle of reluctance is utilized. Up to 94% efficiency, much more efficient than acim alternate current induction motormachine in all speed. The structure of the motor and specifically the structure of its rotor are analyzed, while the basic operating principles are presented and references on commonly used control. The motor which runs at synchronous speed is known as the synchronous motor. Mar 19, 2018 the construction of a synchronous motor is very similar to the construction of an alternator. The stator core is constructed with thin silicon lamination and insulated by a surface coating, to minimize the eddy current and hysteresis losses. The stator of the motor has the main and auxiliary winding.
Just like any other motor, the synchronous motor also has a stator and a rotor. There is no practical application for a large synchronous reluctance motor. Rotor design of linestart synchronous reluctance motor to. All about reluctance motors what they are and how they work. Both are synchronous machines where one we use as a motor and the other as a generator. Jul 11, 2019 synchronous motors are a doubly excited machine, i. In this chapter, we shall focus our attention on the construction, working and. Permanent magnets are mounted on the rotor of a bldc motor, and stator is wound with specific number of poles. Ee6703 unit 1 synchronous reluctance motors 1 prepared by. Another way of saying this is that it has zero slip under usual operating conditions. Synchronous motor construction is very similar to that of a synchronous generator.
There are a large number of control methods for pmsm, which is selected depending on the construction of the electric motor and the scope. Abb synchronous reluctance motor and drive package. The coils wound around diametrically opposite poles are connected in series and the three phases are energized from a d. A permanent magnet synchronous motor and reluctance motor requires a control system for operating vfd or servo drive. Due to the wide use of electric motors in the world take into account that. Analytical design of a synchronous reluctance motor srm. The construction of a synchronous motor is very similar to the construction of an alternator. Jun 11, 2017 the operation of the synchronous induction motor is explored in this video. Reluctance motor basic operating principle youtube. Synchronous reluctance motorconstruction, working principle and types pnb.
The synchronous motor working principle is based on the principle of magnetic locking between stator and rotor poles. When w and wm are converted into cycles per second or hz and revolutions per minute respectively, we have. A technological and smart solution for ever increasing demand for high efficiency and cost reduction. Synchronous reluctance motordrive package for machine. Synchronous reluctance motordrive package for industrial. Looking back to the history to jump ahead in the future. It is usually assumed that windings of pmsrm are ributed sinusoidally. Perhaps one of the simplest electrical machines due to its construction, where only stator. The stator of the single phase reluctance and induction motor are same. Synchronous machines 2 in this chapter, we concentrate on conventional synchronous machines whereas the brushless dc motors will be discussed later in a separate chapter.
The stator has 30 slots, so each coil has a 180 degree pitch. 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. All construction work more preferred the pipe for wiring and water in that. The advantages of the synchronous reluctance motor ee. It generates torque on the principle, that any unmagnetised magnetic material will try to align itself along the path of least magnetic reluctance path. Owing to its characteristics to behave at any electrical power factor, it is used in power system in situations where static capacitors are expensive synchronous motor finds application where operating speed is less around 500 rpm and high power is required. Pdf efficiency analysis of synchronous reluctance motors. Analytical design of a synchronous reluctance motor srm pag. Just like any other motor, it consists of a stator and a rotor. The reluctance motor has basically two main parts called stator and rotor. Other members of the family are the directcurrent dc motor or generator, the induction motor or generator, and a number of derivatives of all these three. This doubly salient arrangement is very effective for electromagnetic energy conversion. The efficiency of ac servo motor is less and is about 5 to 20%. The subtypes of reluctance motors include synchronous reluctance motors and switched reluctance motors, and each use reluctance in unique ways.
Synchronous reluctance motor electric motor rotating. The rotor has neither magnets nor windings and suffers virtually no power losses. What is synchronous motor and types electrical mastar. One form of reluctance motor is shown in cross section in the figure. Its stator winding which consists of a we provide threephase supply to threephase stator winding, and dc to the rotor winding. A reluctance motor is a type of synchronous electric motor. Synchronous motors controlled by variablespeed drives are. If the rotating field of a large synchronous motor with salient poles is deenergized, it will still develop 10 or 15% of synchronous torque.
The synchronous speed is the constant speed at which motor generates the electromotive force. They are capable to achieve very high efficiency level and to gain the maximum efficiency class ie4 of iec 6003430 standard. The operation of reluctance motor with diagram a media to. Future of wood drying, synchronous reluctance synrm motors in wood drying applications english, finnish pdf leaflet. 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. Sr motor principle and related torque general equation. The load inertia should be within the limits, for proper effectiveness. 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.
You get the performance of a permanent magnet motor together with the costefficiency, simplicity and servicefriendliness of an induction motor. The construction of a synchronous motor with salient pole rotor is as shown in the figure at left. A singlephase linestart synchronous reluctance motor lssynrm has both conductor bars and flux barriers in the rotor. There can be two types of bldc motor on the basis of. In terms of efficiency and power density, synchronous reluctance motors synrms represent a major step forward in sustainable electric motor technology. In transient state from start to reach synchronous speed, the motor characteristics are determined by conductor bars, and the characteristic profile has an irregular form as shown in fig.
Synchronous machine structures stator and rotor the armature winding of a conventional synchronous machine is almost invariably on the stator and is usually a three phase winding. The 3 phase stator winding carrying 3 phase currents produces 3 phase rotating magnetic flux. This video gives basic operating principle of reluctance motor. 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. What are the applications of synchronous reluctance motor. Unlike a conventional synchronous motor, both the rotor and stator of a switched reluctance motor have salient poles.
For our discussion, 4 pole rotor constructi6n is elected. A same synchronous machine can be used as a synchronous motor or as an alternator. The basic features of this motor with regard to the other types of motors are shown. The stator has axial slots inside, in which three phase stator winding is placed. Synchronous reluctance motor ideal for pumphydraulic applications. The synchronous motor is used for converting the electrical energy into mechanical energy. The stator poles have concentrated winding rather than sinusoidal winding. Reluctance motor a single phase synchronous reluctance motor is basically the same as the single cage type induction motor. Jul 25, 2018 synchronous reluctance motorconstruction, working principle and types pnb. A reluctance motor is a type of electric motor that induces nonpermanent magnetic poles on. Perhaps one of the simplest electrical machines due to its construction, where only stator windings and a magnetic rotor in a saliency form are used. The article is devoted to the comparative research of performances of controlled drives with a synchronous reluctance motor synrm and with an induction motor im in a pump application.
The life of ac servo motor depends on bearing life. Ie5 synchronous reluctance motors, 9akk107743 en 122019 english pdf catalogue product note. Hi friends, in this article, i am going to discuss the construction and working of synchronous motor. We will look into the construction details of the various parts one by one in detail. Synchronous reluctance technology combines the performance of the permanent magnet motor with the simplicity and servicefriendliness of an induction motor. Rather than using a traditional 3phase configuration, i was interested in investigating a highphase order machine with each stator slot corresponding to an individually controlled phase. Synchronous reluctance motor intoduction concepts youtube.
So rotor has 4 salient poles without any exciting winding as shown in the fig. Other articles where reluctance motor is discussed. To achieve this a suitable theoretical model is essential, thus a simple but complete motor model is developed. Although introduced over a century ago, electric motors continue to experience bursts of innovation and recent years have seen remarkable progress in electric motor efficiency improvements. This type of motor starts and comes up near synchronous speed as an induction motor, then pulls into synchronism and runs at synchronous speed as a reluctance motor. The synchronous reluctance motor magnetic reluctance is the magnetic. Oct 26, 2012 the threephase synchronous reluctance motor synrm is presented as a possible alternative in allelectric ship applications. Synchronous motor and induction motor are the most widely used types of ac motor. Synchronous reluctance motor free download as powerpoint presentation. Permanent magnet synchronous reluctance motor design. Essential parts of the synchronous motor are the same as those of the synchronous generator i. Synchronous reluctance motorconstruction, working principle. A synchronous electric motor is an ac motor distinguished by a rotor spinning with coils passing magnets at the same rate as the alternating current and resulting magnetic field which drives it. Synchronous motors are available in a wide range, generally rated between 150kw to 15mw with speeds.
Just like any other electric motor, a bldc motor also has a stator and a rotor. To understand the working of synchronous motor, let the stator of the synchronous motor be wound for two poles. Reluctance motors can deliver high power density at low cost, making them attractive for many. A synchronous electric motor is an ac motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current. The synchronous type ac servo motor uses permanent magnet while induction type doesnt require it. 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. A 2pole synchronous reluctance motor is shown in figure 2.
Working of synchronous motor your electrical guide. In this chapter we are going to discuss about the construction and working principle of the reluctance motor. Among the electrical machine drives such as induction motor drives, dc motor and permanent magnet synchronous motor drives, srm drives are growing rapidly in numbers. 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. This is a 4phase machine with 4 stator pole pairs and 3 rotorpole pairs 86 motor.