The electrical machines 3 notes pdf em iii notes pdf book starts with the topics covering constructional features of round rotor and salient pole machines, suppression of harmonics, regulation. Construction of alternator synchronous generator mcqs. The synchronous electrical generator also called alternator belongs to the family of electric rotating. There are mainly two types of rotors used in construction of alternator. For the slip test, the alternator should be driven at a speed, slightly less than the synchronous speed. Pdf electrical machines 3 pdf notes em iii notes 2019 sw. This paper sets to present the dynamic model and simulation of a threephase salient pole. To find xd and xq of a salient pole rotor type synchronous machine by slip test apparatus. How does electrical degree differ from mechanical degree. Download link for eee 5th sem ee6512 electrical machines 2 laboratory manual is listed down for students to make perfect utilization and score maximum marks with our study materials.
Krishna vasudevan,department of electrical engineering,iit madras. An improved analytical model for salient pole synchronous machines under general eccentricity fault hamidreza akbari department of electrical engineering, yazd branch, islamic azad university, yazd, iran abstractthis paper develops a more precise analytical model for calculating salient pole synchronous machine spsm inductances. The proposed smpi voltage regulator has been evaluated experimentally by using a laboratory setup whose structure was presented in fig. Unitiii objective the objective of this unit is to acquire the detail knowledge on parallel operation and load sharing of synchronous generators and the effect of change of excitation and mechanical power input in synchronous. Study of salient poles synchronous generator by finite elements analysis. Methods to determine voltage regulation of alternator. The field coils may be on the stator or on the rotor. Sample ee8401 question paper electrical machines 2.
Analysis of nonsalient pole synchronous generator using phasor diagrams. Vector diagram correlation of leading and lagging power. What are the various types of rotors used in the alternators. Sep 03, 2016 ac machines two reaction model of salient pole machines, phasor diagram of salient pole machines. Construction of a salient pole rotor is as shown in the figure at left. Parallel operation of two alternators mcqs with answers. What are the advantages of salient pole type construction. Oct 29, 2014 modelling and analysis of electric machines by dr. As the field continues to turn and the north pole starts to move away from the winding, the current decreases as the strength of the field cutting the winding decreases. An alternator has full load regulation of 4% when the power factor of the load is 0. It is also defined as the number of slots per pole. Actually, salient pole generators would be preferred in all cases. The circuit diagram shown below consists of voltage source e1, voltage source e1 and load which consists of one resistor in series with an. There are some disturbing factors in salient pole alternators which are analysed below.
The synchronous generator is connected to a threephase power grid emulator. Are you looking for determination the regulation of alternator by two reactance theory. It has a large number of projecting salient poles, having their cores bolted or dovetailed onto a heavy magnetic wheel of castiron, or steel of good magnetic quality fig. Mod01 lec40 reactances of salient pole synchronous machines. Mar 04, 2020 there are mainly two types of rotors used in construction of alternator. Other members of the family are the directcurrent dc motor or generator, the induction motor or generator, and a number.
On the theory of salient pole alternators with electromagnet. Salient pole synchronous generation are mostly used in hydro power plant. Figure 3 illustrates a simplified threephase, two pole ac generator. Phasor diagrams regulation of salient pole alternators.
Oct 26, 2016 the frequency shown by crutshow seems to me the right one for full wave rectifier 6 diodes as usually found in the cars alternator. Chapter 4 synchronous generators or alternators notes. A salientpole double star synchronous machine supplied by threelevel inverters lazhari nezli mohand oulhadj mahmoudi. Dc motorscharacteristics including derivation of shunt, series and compound motors and their applications, speed control of shunt and series motors, testing of d.
Regulation of alternator at full load is found to be. Objective questions on alternator or synchronous generator. This document is highly rated by ssc je students and has been viewed 848 times. This work relates to the study of the vector control of the salientpole double star synchronous machine drive dssm fed by threelevel inverters which are controlled by pwm hysteresis strategy. The non salient pole types are used for high speed alternators called turbo alternators with speeds ranging from 1500 to 3000 r. Alternator generator mcqs with explanatory answers. Ig is the ignition input that turns on the alternator regulator assembly.
These type of machines have salient pole or projecting poles with concentrated field windings. Blondels two reaction theory, phasor diagram, direct axis and quadrature axis synchronous reactances, power angle characteristics, slip. Why the bmw alternator is failed to charge there are certain components in your bmw that play a crucial role in the smooth running and better performance of the car. What are the advantages of salient pole type construction used for synchronous machines. Download istudy android app for complete jntuh syllabus, results, timetables and. Buy electrical machines 3 book online at best prices in india on. We collected most searched pages list related with determination the regulation of alternator by two reactance theory and more about it.
Salient pole definition of salient pole by merriamwebster. Pdf analysis of nonsalient pole synchronous generator. In salient pole type of rotor consist of large number of projected poles salient poles mounted on a magnetic wheel. The stator and rotor are classified by the number of poles they have.
Ventilation or cooling of an alternator the slow speed salient pole alternators are ventilated by the fan action of the salient poles which provide circulating air. A salient pole synchronous motor is running at no load. Salient pole rotors allow windings on the pole itself, giving good control over the flux and allowing for more turns and therefore more flux. The air gap flux per pole contains a fundamental component of 0. The alternator runs at various rpm which varies the frequency since it is driven by the engine. The magnetic path is characterized by poles, locations at equal angles around the rotor at which the magnetic field lines pass from stator to rotor or vice versa. However, in a salient pole machine, the two mmfs do not act on the same magnetic circuit. About this video i am describe in this video open circuit characteristic and short circuit characteristic. In an alternator if the armature reaction produces magnetisation of the main field the power factor should be. Determination of load angle for salientpole synchronous machine. Voltage regulation of synchronous machine is generally calculated in percentage of full load terminal voltage. Electrical machines 2 question paper ee8401 pdf free download. One such system is the alternator which is used for generating the electricity for its electrical components as well as responsible for maintaining its battery charge.
The cardioid diagram method of determining the voltage regulation \ud of salient pole alternators and the load voltage increase phenomenon\ud in alternators with permanent magnet excitation. In case of salient pole machines the air gap is not uniform in length around the inner periphery of the armature. This rotor has solid poles and a striponedge field winding. In some cases the end of the rotor shaft is not free to be used and mounting of an encoder is impossible. 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. The power output of a synchronous generator is the sum of the power due to the directaxis current d and the power due to the quadratureaxis current. Salient pole and non salient pole synchronous machine. Non salient pole generators will have smaller diameter and longer axial length. The synchronous electrical generator also called alternator belongs to the family of electric rotating machines. To provide direct current with low ripple, a polyphase winding is used and the pole pieces of the rotor are shaped claw pole. Salientpole machines have an additional winding in the rotating mem ber. Pscad example salient and nonsalient models for synchronous. Name enrolment number roll number chanchal jain slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
The salient pole type of rotor is generally used for slow speed machines. The phasor diagram of a salientpole synchronous generator. Slip test and reluctance power of alternators mcqs with. Pdf study of salient poles synchronous generator by. In order to derive various conditions for power in both alternators and synchronous motors, let us consider the general problem of power flow through inductive impedance. Ee8401 question paper electrical machines 2 regulation 2017 anna university free download. Vector diagram correlation of leading and lagging power factor in salient pole synchronous. A graphical method has been developed for rapidly determining from two reactances the regulation of alternators for a wide range of power factor. The shaft and pole bodies are of integral construction, produced from a single normalized carbon steel forging.
Salient and nonsalient pole synchronous generator physics. A three phase, 10 pole, 600rpm, star connected alternator has 12 slots per pole with 8 conductors per slot and the windings are short chorded by 2 slots. Synchronous generator salient pole vs non salient pole. Alternator and poles electronics forum circuits, projects. It is done only on salient pole alternators non uniform field. In generators and alternators, the rotor designs are salient pole or cylindrical.
Modern alternators prefer rotating field type of construction. Ppt alternator powerpoint presentation free to view. Ee6512 em2 lab manual, electrical machines 2 laboratory. The first method uses optical encoder to detect the rotor position.
Voltage regulation of synchronous machine is defined as the difference between terminal voltage at no load and terminal voltage at full load and excitation, speed must remain same. The drawback is it is weaker mechanically so it usually limits the rotor speed. The direct and quadrature axis components of current and reactance are same as defined earlier for the synchronous generators. Salient pole synchronous motor electrical engineering. Determination of load angle for salientpole synchronous. The rotor winding is provided on these poles and it is supported by pole. When neither pole is nearest the winding, the current through the winding is zer o. Understanding the alternator four wires connect the alternator to the rest of the charging system. Pscad example salient and nonsalient models for synchronous generator page 1 salient and nonsalient models for synchronous generator salient pole or nonsalient pole synchronous generators can be identified in pscad by defining the number of qaxis damper windings. Here you can download the free lecture notes of electrical machines 3 pdf notes em iii notes pdf materials with multiple file links to download. No name of experiment page no 1 to perform the brake test on a 3 slip ring induction motor and obtain its performance characteristics 2 to start a 3phase slip ring induction motor by rotor resistance starter. Nonsalient pole or cylindrical rotor or round rotor machines. Salient pole definition is a magnet pole that projects toward the armature of an electric machine. 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.
A slidingmode voltage regulator for salient pole synchronous. Salient pole synchronous generators are employed in hydropower plants. Voltage regulation of synchronous machines alternator by. One pole pitch is equals to 180 electrical degrees. On the theory of salient pole alternators with electromagnet and with permanent magnet excitations. The rotor winding is provided on these poles and it is supported by pole shoes. Synchronizing alternators with infinite bus bars synchronizing power torque parallel operation and load sharing effect of change of excitation and mechanical power input. An equivalent circuit for the salientpole synchronous machine. The salient pole type of rotor is generally used for slow speed machines having large diameters and relatively small axial lengths. Pdf brushless exciter modeling for small salient pole. Pole of the field moves past the winding, a large current flows through the winding. Alternator on load synchronous reactance vector diagrams of loaded alternator voltage regulation rotherts m. Blondels two reaction theory salient pole machine theory. Solid salient pole motor synchronousmotor ge power.
This paper presents two methods for load angle determination for salient pole synchronous generator. Dynamic modelling and simulation of salient pole synchronous. B is the alternator output wire that supplies current to the battery. The distance between the centres of two adjacent poles is called pole pitch. Brushless exciter modeling for small salient pole alternators using finite elements. The frequency shown by spec seems to me the right one for half wave rectifier 3 diodes. Two reaction model of salient pole machines, phasor diagram. Salient pole alternators and blondels two reaction theory. The slow speed salient pole alternators are ventilated by the fan action of the. An equivalent circuit for the unsaturated salient pole synchronous machine operated under balanced, steadystate conditions is derived from a consideration of the voltage and current equations implicit in the phasor diagram.
Blondels two reaction theory, phasor diagram, direct axis and quadrature axis synchronous reactances, power angle characteristics, slip test. Base values, transformation ratio, and rotor parameters referred to the stator. The machine which produces 3phase power from mechanical power is called an alternator or synchronous generator. Every synchronous machine has a natural time period of free oscillation. Designed, built and tested in the motor factory, solid salient pole rotors are suitable for applications requiring long duty cycles. When an alternator is supplying unity power factor load, the armature reaction will produce. Automotive alternators are usually beltdriven at 510 times crankshaft speed. They are used for high speed operation typically speed will be 1500 and 3000 rpm better in dynamic balancing because of absence of salient poles. The problem is that the centrifugal forces at high rpm i. It is a test done in alternator to measure the value of direct axis synchronous reactancexd and quadrature axis synchronous reactancexq. Get details of determination the regulation of alternator by two reactance theory. Anna university regulation 20 eee 5th sem ee6512 em2 labelectrical machines 2 laboratory manual. Synchronising method, effect of wrong synchronising, load sharing between alternators in parallel.
Two reaction theory of salient pole synchronous alternator. Ee8401 question paper electrical machines 2 regulation 2017. 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. Now let us discuss about construction of alternator or synchronous machine. Each of the three coils generates an ac voltage sine wave as illustrated in figure 4a and 4b. The projected poles are made up from laminations of steel. Apr 11, 2020 chapter 4 synchronous generators or alternators notes, electrical machines, electrical engineeri ssc je notes edurev is made by best teachers of ssc je. Model the dynamics of threephase roundrotor or salient. Its field current is switched off, the motor will a come to stop. But the alternator conductors are calculated for a definite current and the insulation at magnetic system are designed for a.
This paper presents two methods for load angle determination for salientpole synchronous generator. Dynamic modelling and simulation of salient pole synchronous motor using embedded matlab onah, c. Derivation of various power conditions in alternators and. Generatorno load and load characteristics, types of excitation, armature reaction, use of interpoles and pole phase compensating winding only qualitative treatment. Alternators lab viva questions and answers pdf free download for engineering students alternators interview mcqs objective questions. Novdec 2016 salient pole types are used for low speed alternators with speeds ranging from 125 to 500 r.
The theory which gives the method of analysis of the disturbing effects caused by salient pole construction is called two reaction theory. Hence the effect of armature reaction in the case of a salient pole synchronous machine can be taken as two components one acting along the direct axis coinciding with the main field pole axis and the other acting along the quadrature axis interpolar region or magnetic neutral axis and as such the mmf components of armaturereaction in a salient pole. This type of construction is for the machines which are driven by hydraulic turbines or diesel engines. The analysis of salient pole synchronous motor is based on the blondels two reaction.
Salient pole generator description the salient pole generator explores the principles and characteristics of salient pole generators. It contains everything needed for salient pole generator experiments including resistive, capacitive and inductive load banks. The effect of load changes on a synchronous generator operating alone. The salient pole rotor have a large number of projecting poles carrying the field coils. The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Synchronous machines laminated iron core with slots insulated copper bars are placed in the slots to form the threephase winding metal frame details of a generator stator. S is used by the regulator to monitor charging voltage at the battery. Cylindrical rotor alternators are usually long, and the problem of air f low requires very special attention.
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