Number 3 9 In 8, if the is keptconstant, the andc. load sdi tndr bae adb. load basotba. Resistive Tolequivalent of a and ex-tance of a 3-phase Draw theplain the of all the parameters.terminals? W ama orli oaleSYNCHRONOUSSYNCHRONOUS GENERATORSed only 27 times. Consequently, the effi-nachine was bound to increase with size.nal machine produced an output ofe larger machine has a mass of 540 kgs 81 kW. Consequently, it produces= 150 W/kg which is 3 timesmachines is a very important matter.frequency if the speed isa. 1000 r/minb. 5 r/minIntermediate levelWhat is meant by the synchronous reac-of a 3-phase generator? Draw the%3Dbefore.Questions and Problemser generator is therefore relativelycheaper than the smaller machine. Ashty-one 1 kW generators were used tokW, their combiìned mass would be01Practical levelWhat are the advantages of using a stationary1.plain the meaning of all the parameters.armature in large synchronous generators?Why is the stator always connected in wye?2.State the main differences between steam.1620 kg. This generating center wouldme more costly and take up more floorhe single 81 kW generator. 1Ovilmer matter of interest, the moment of in-rotor is proportional to its mass and thes radius. Hence, when linear dimensionsJ will increase by a factor of J = mr² =3 = 243. The moment of inertia ofnachine is therefore 243-0.0075 kgm² =IIturbine generators and salient-pole genera-tors. For a given power output, which ofthese machines is the larger?a schematic circuit diagram, show how therotor in Fig. 7 is excited.Referring to Fig. 13, calculate the exciting12current needed to generate a no-load linevoltage oflod a. 24.2 kVb. 12.1 kVA 3-phase generator possesses a synchro-nous reactance of 6 N and the excitationvoltage E, is 3 kV per phase (ref. Fig. 19).Calculate the line-to-neutral voltage E for aresistive load of 8 N and draw the phasordiagram.a. In Problem 13, draw the curve of Eversus I for the following resistiveloads: infinity, 24, 12, 6, 3, 0 ohms.b. Calculate the active power P per phasein each case.3.In analyzing a hydropower site, it is foundthat the turbines should turn at close to%3D%3D350 r/min. If the directly coupled genera-%3DILOUtors must generate a frequency of 60 Hz,13ristics of the larger generator arew. They are in striking contrast toW machine.calculate the following:a. The number of poles on the rotorb. The exact turbine speed81 kW1080 V, 3-phase43.2 AAn isolated 3-phase generator produces a4.no-load line voltage of 13.2 kV. If a loadpecsbe of14having a lagging power factor of 0.8 isconnected to the machine, must the excita-S ction be increased or decreased in order tomaintain the same line voltage?inertiaug pometer5.C. Draw the curve of E versus P. For whatvalue of load resistance is theoutput a maximum?smido ator can be connected to a 3-phase system?9.Calculate the number of polesWkg15poweris temperature rise. Whentripled, the heat-dissipatingnachine increases 9 times but27 times. Hence, the power dis-meter increases by a factor of 3.unless better cooling means aregenerator shown in Fig. 11.circumference of the stator.8.the following loads are connected to Tsterminals? w amaa. Resistive loadb. Inductive load oE, 32440 Vhas to be limited to a maximum ofX, = 144 N%3DR=17 Numixam sSrb gatarabaiw s

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In this question, 
If frequency of the rotor is given f= 60Hz
We need to find out the number of…