Part B: If the load Speed-Torque characteristics (including the mechanical losses) is described by following equation: TL- |11.1+(5/150) Nrj. as shown in Fig.1. Determine the speed control range(maximum range) for three of the following cases: a- Reducing the stator voltage using autotransformer. b- Inserting external rotor resistance. c- Reducing the input voltage by 35%. d- Reducing the input voltage so that Vaew-0.85 V. Speed-Torque curve Shat spee pm N'anbe

Part B: If the load Speed-Torque characteristics (including the mechanical losses) is described by following equation: TL- |11.1+(5/150) Nrj. as shown in Fig.1. Determine the speed control range(maximum range) for three of the following cases: a- Reducing the stator voltage using autotransformer. b- Inserting external rotor resistance. c- Reducing the input voltage by 35%. d- Reducing the input voltage so that Vaew-0.85 V. Speed-Torque curve Shat spee pm N'anbe

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter12: Power System Controls

Section: Chapter Questions

Problem 12.12P

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| 40% | Part B: If the load Speed-Torque characteristics (including the mechanical | Tasses) is described by following equation: TL= [11.1+(§/150) Nrl, as shown in Fig 1. | Determine the speed control range(masimum range) for three of the following ases: | a- Reducing the stator voltage using autotransformer. b- Inserting extemal rotor resistance. [ | Reducing the input voltage by 35%. | | o Reducingteiopus voiage st V=085 Ve
For the given electromechanical system with all parameters in SI units, the motor used develops 50 Nm of torque at 3000/pi in rpm when 15 volts applied. It is stalled at this DC voltage with 150 Nm of torque. The armature inertia is 5 kg.m2 and damping is 2 N.m.s/rad. What is the equivalent load damping DL at the N3 port
An unknown voltage is applied to an asynchronous motor with a three-phase stator connected in star with the number of pole pairs 10. The torque-speed (Moment-slip) relationship of the motor can be linearized with the equation M=Ks in the stable region. Here k is a coefficient and its value is 100Nm. and S represents the shift. While the friction is neglected, the Moment produced by the engine is 9 Nm. As measured. The single-phase equivalent circuit parameters of the rotor reduced to the stator are given below. Rs = Rr`= 10, Xsσ(X1)= X'rσ(X2) = 20, RFe= 400 ohms, Xm= 12.5 ohms a) Calculate the rotational speed of the motor in rpm b) Calculate the input and output power and efficiency of the motor. (Use L equivalent circuit) a) 547 rpm, P input 6245 watts, P output 516 watts, efficiency 83% b) 548 rpm, Pinput 626 watts, Poutput 517 watts, efficiency 84% c) 546 rpm, Pinput 624 watts, Poutput 515 watts, efficiency 82% d) 545 rpm, Pinput 623 watts, Poutput 514 watts, efficiency 81%
A gas turbine, 2-pole, 3? synchronous generator rated at 200 MW is connected to the grid (presumed to be an infinite bus). The electrical operating frequency of the grid is 60 Hz, and the slope of the frequency-power curve for the generator is 15 MW/Hz. a. If the no-load setpoint for the generator is set to 63.5 Hz, how much active power will the generator provide to the grid? b. Neglecting system losses, what is the torque provided by the gas turbine? c. What would happen if the no-load setpoint for the generator is set to 59 Hz?
It has been determined by test that thesynchronous reactance Xs and armature resistance raof a 2,300-V, 500-VA, three-phase synchronousgenerator are 8.0 and 0.1 Ω, respectively. If themachine is operating at rated load and voltage at apower factor of 0.867 lagging, find the generatedvoltage per phase and the torque angle.
the armature series field and shunt field resistance of a 125 kw, 250V long shunt cumulative compound DC generator are 0.025ohms, 0.01ohms and 30 ohms, respectively. If the stray power stray loss at rated load is 25 kW, determine the power in the shunt field. Assume a astray load loss of 1% of the load power output (note: Input power generator is equal to the motor brake horsepower, Pin=Pl+Plosses) Choices A. 2034.5 W B.2082.5 W C. 2065.5 W D. 2053.5 W
A 60Hz, 4 pole turbogenerator rated 200MVA, 11kV has an inertia constant of 8.0 MJ/MVA. (a) Find the stored energy in the rotor at synchronous speed. (b) If the mechanical input is suddenly raised to 180MW for an electrical load of 125MW, find rotor acceleration, neglecting mechanical and electrical losses. (c)If the acceleration calculated in part(b) is maintained for 10 cycles, find the change in torque angle.
A 12-phase ∆-connected 3200 V (line-to-line), 12,000 kW, 50 Hz, twelve-polesquirrel-cage induction drive is designed for electric vehicle use. The drive has thefollowing equivalent parameter values in Ω/phase referred to the stator:R1= 0.697 Ω R2= 0.328 Ω Rm1 = 226 ΩX1 = 0.549 Ω X2 = 0.456 Ω Xm1 = 31.573 ΩThe total friction, windage, and core losses are assumed to be constant at Plosses=1156 W, independent of load.a)Draw the equivalent circuit for this drive and show the relevant parameters onthe circuit.For a slip value of s = 0.032 and using the above equivalent circuit parameters,determine: b) The stator current and the power factor c) The synchronous speed and the rotor speed for this drive d) The torque generatede) The input power for this operating conditionf) The efficiency when operated at rated voltage and frequencyg) Considering the design of this motor, state if it is possible to start this drive witha slip ring starter. Give reasons to justify your answer. just need answer…
A 12-phase ∆-connected 3200 V (line-to-line), 12,000 kW, 50 Hz, twelve-polesquirrel-cage induction drive is designed for electric vehicle use. The drive has thefollowing equivalent parameter values in Ω/phase referred to the stator:R1= 0.697 Ω R2= 0.328 Ω Rm1 = 226 ΩX1 = 0.549 Ω X2 = 0.456 Ω Xm1 = 31.573 ΩThe total friction, windage, and core losses are assumed to be constant at Plosses=1156 W, independent of load.a)Draw the equivalent circuit for this drive and show the relevant parameters onthe circuit.For a slip value of s = 0.032 and using the above equivalent circuit parameters,determine:b) The stator current and the power factorc) The synchronous speed and the rotor speed for this drived) The torque generatede) The input power for this operating conditionf) The efficiency when operated at rated voltage and frequencyg) Considering the design of this motor, state if it is possible to start this drive witha slip ring starter. Give reasons to justify your answer
A 60 Hz, four-pole 480 V, three-phase, wye-connected induction machine has the following parameters: R1 = 0.2Ω R2’ = 0.3Ω XT = 12Ω The motor is loaded with a unidirectional constant-torque of 40 Nm. A counter current braking is performed on the motor, by interchanging phases A and B. Determine The motor speed at the new steady-state point The operating mode at the new steady-state point. Efficiency of the machine at the new steady-state pint. (Assume negligible core and mechanical loses.)
A 20KW, 440V, short shunt compound dc generator has full load efficiency of 87%. If the resistance of the armature and interpoles is 0.4ohm and that of the series and shunt fields 0.25ohm and 240ohms respectively, calculate the combined bearing friction, windage and core loss of the machine A 10 kW 250 volts self-excited generator, when delivering rated load, has an armature-circuit voltage drop of 5% of the terminal voltage and a shunt field current equal to 5% of the rated load current. The resistance of the armature is 0.02 ohm. Calculate the voltage generated and power output.
3) The conversion ratio of an asynchronous motor with 415 V, 3-phase, 60Hz, 6-pole, Y-connected rotor winding is a = N1 / N2 = 1.5,Parameter values per phase transferred to the stator are given below. a) For the case where slip s = 0.05, calculate the stator current, the torque generated in the motor, with the rotor circuit voltageCalculate the frequency.b) Subtract the Thevenin equivalent.c) The rotor stays stuck while the motor is running under load. Find the rotor current reflected to the stator at this instant.d) Find the maximum torque the motor can produce.e) It is required that the engine initially develops with maximum torque. For this, externalFind the value of the resistance transferred to the stator