Salient pole synchronous generators are mostly used in hydro power plants. Function of a generator rotor this section covers the generator fields function in two main areas. But in real salient pole synchronous generators air gap between. Introduction to synchronous generator the engineering. Difference between cylindrical and salient pole rotor. The field poles are made to rotate at synchronous speed n s 120 fp for effective power generation. But due to uniform air gap in cylindrical pole synchronous machine, both direct and quadrature axis synchronous reactance are. Synchronous generator stator windings are similar to a threephase synchronous motor stator winding. Solid salient pole motor synchronousmotor ge power. Synchronous reactance vector diagrams of loaded alternator voltage regulation rotherts m. The magnetic poles can be either salient sticking out of rotor surface or non salient construction.
Salient poles are laminated in order to reduce eddy currents. This also shows that it is possible to generate an emf even if the excitation e0 is zero. Pdf in this paper, various performance equations are derived from phasor diagrams of a three phase nonsalient pole cylindrical rotor. In case of salient pole synchronous machine, the air gap is non uniform. Non salient pole b stator windings or armature windings the rotor of a synchronous generator is a large electromagnet and the magnetic poles on the rotor can either be salient or non salient construction.
The generated frequency of 50 hz is entirely a function of the driven speed. In either case, the flux of the field is fairly uniformly distributed throughout. Two reaction theory salient pole synchronous machine. Pdf analysis of nonsalient pole synchronous generator using. Ger4212 ge generator rotor design, operational issues. Rotors are made laminated to reduce eddy current losses. For energy generation in wind turbines, a steam turbine or hydro turbines synchronous generator is used. This type of construction is commonly employed in machines coupled to hydroelectric turbines which are inherently slowspeed ones so that the salient pole synchronous generator has multiple pole pairs as different from machines coupled to highspeed steam turbines 3,0001,500 rpm which have a two or four pole structure. In practice, the difference between the rotational speed at peak power and at idle is very small, about 1%. The turbine converts some kind of energy steam, water, wind into mechanical energy, as illustrated in fig. The difference between asynchronous and synchronous generator. Difference between salient pole and non salient pole rotor used in synchronous generator. Salient pole synchronous generator power angle curve. Non salient pole rotors are normally used for rotors with 2 or 4 poles rotor, while salient pole rotors are used for 4 or more poles rotor.
When a synchronous generator is connected to a large interconnected system containing many other synchronous generators, the voltage and frequency at its ar. Salient pole and non salient pole synchronous machine. Pdf analysis of nonsalient pole synchronous generator. Explain the constructional details of alternator in. Comparative analysis of salient and nonsalient pole brushless. The two coils of the 4 pole generator synchronous machine working principle of fig. The pictures below show the stator and rotor of a hydroelectric generator and the rotor of a turbine generator. Capability curvebased generator protection minimizes. In this paper, various performance equations are derived from phasor diagrams of a three phase nonsalient pole cylindrical rotor synchronous generator of.
Salient pole generators will have large diameter and short axial length pole shoes cover 23 of the pitch salient poles are laminated in order to reduce eddy currents they are used in hydraulic turbines or diesel engines salient pole generators will have typical speed about 100 to 375 rpm. The spider carries rotor core and poles are radially fitted onto the core. As shown in figure 1, the rotor can be of either the salient pole type or the cylindrical non salient pole type. Salient and nonsalient pole synchronous generator thread starter oliskap.
The theory proposes to resolve the given armature mmfs into two mutually perpendicular components, with one located along the axis of the rotor of the salient pole. Ee 340 spring 2011 university of nevada, las vegas. The end view of a typical 6 pole salient pole rotor is shown below in the figure. The ac generator or synchronous generator is a machine which converts the mechanical power or energy into electrical power the construction of an alternator is very similar to the dc generator but the main difference between them in dc generator the armature winding is the rotating part and field winding is the stationary part whereas in an alternator the. Construction of a synchronous machine circuit globe. Pdf on jun 30, 2019, thant zaw oo and others published compatibility design of nonsalient pole synchronous generator find, read and cite all the.
The power output of a synchronous generator is the sum of the power due to the direct. The equivalent circuit of the stator and the cylindrical rotor of the non salient pole of the synchronous generator relation are shown in figure 4. Since the rotor is subjected to changing magnetic fields, it is made of steel laminations to reduce eddy current losses. Salient pole generators will have large diameter and short axial length. Mediumspeed synchronous generators mediumspeed synchronous generators product overview product overview our new mediumspeed threephase highvoltage generators in salient pole design are available at 900 mm to 1,120 mm shaft height with eight to twelve poles. Understanding of direct and quadrature axis synchronous. Designed, built and tested in the motor factory, solid salient pole rotors are suitable for applications requiring long duty cycles. Explain the constructional details of alternator in detail with neat sketches. Analysis of nonsalient pole synchronous generator using phasor. Pdf compatibility design of non salient pole synchronous. Pdf compatibility design of nonsalient pole synchronous.
Non salient pole or cylindrical rotors are cylindrical in shape having parallel. The machine which converts mechanical power into ac electrical power is called. The machine used for this experiment is somewhat salient, but the impact of the salient is negligible. In this paper, various performance equations are derived from phasor diagrams of a three phase non salient pole cylindrical rotor synchronous generator of known armature resistance and of ignored armature resistance for lagging, unity and leading. Non salient or cylindrical pole type salient pole type. The rotor of a synchronous machine is a large electromagnet. A four pole, threephase synchronous generator is rated 250 mva, its terminal voltage is 24 kv, the synchronous reactance is.
This difference in per cent of the synchronous speed, is called the generators slip. In this type, salient or projecting poles are mounted on a large. Salient pole also called spider or projected pole means the rotor has. Difference between salient pole and non salient pole rotors or salient pole alternator and cylindrical alternators used in synchronous generator. This rotor has solid poles and a striponedge field winding. This paper is focused design calculation of 30 mva, 11 kv, 50 hz, two pole non salient poles synchronous generator that use in gas turbine power plant. Construction of synchronous machines the rotor of a synchronous machine is a large electromagnet. What is the difference between a salient pole and a. It is important to note that the endcore heating phenomenon described does not occur in previously salient pole generator s. Salient pole generators will have typical speed about 100 to 375 rpm.
Salient pole rotors generally need damper winding to prevent rotor oscillations during operation. Explained the difference between salient pole and non salient pole rotor compare salient pole and cylindrical rotor difference between salient pole and c. Commercially used salient pole and a prototype nonsalient pole high speed multipole brushless synchronous generator bsg have been presented. Non salient pole rotors are normally used for rotors with 2. Where, f signifies the alternating current frequency and the p represents the number of poles. The shaft and pole bodies are of integral construction, produced from a single normalized carbon steel forging. Construction of synchronous machines in a synchronous generator, a dc current is. As the speed of the water turbine is slow hence more number of poles.
The choices of specific loadings are magnetic loading and electric loading are involved in that. They are used in hydraulic turbines or diesel engines. Non salient pole or cylindrical rotors are cylindrical in shape having parallel slots on it to place rotor windings. Synchronous machines notes part2 electric equipment. If 50 hz is desired from a four pole generator, the generator must be driven at 1500 rpm. Flux distribution is relatively poor than non salient pole rotor, hence the generated emf waveform is not as good as cylindrical rotor.
Flux distribution is relatively poor than non salient pole rotor hence the generated emf wave form is not as good as cylindrical rotor. Synchronous generator rotor fields may be either salient or non salient pole. The synchronous generator is the type of ac generator. Poles of identical dimensions are assembled by stacking laminations to the required length. Two reaction theory salient pole synchronous machine two reaction theory was proposed by andre blondel. Rotors used in synchronous alternators can be classified into. The series connection gives double the voltage of one coil and can handle the. Cylindrical and round rotors are used for 6 pole application.
Synchronous generator salient pole vs non salient pole. Difference between salient pole and nonsalient pole rotor. Eeeb344 electromechanical devices chapter 5 chapter 5. Salient pole rotors generally need damper windings to prevent rotor oscillations during operation. Difference between salient pole and non salient pole. There are mainly two types of synchronous generator from rotor construction point of view. Salient pole synchronous motor power developed by a salient pole synchronous motor. Ok, fine that centrifugal forces at high rpm are to much for salient pole rotors, so non salient rotors are used instead. Construction of alternator synchronous generator types. In this paper, various performance equations are derived from phasor diagrams of a three phase non salient pole cylindrical rotor synchronous generator of known armature resistance and of. Synchronous machine constitutes of both synchronous motors as well as synchronous generators.