Electerical Machines The magnetization curve for a separately excited DC generator is shown in Figure Q4(c)(c). The generator is rated at 6 kW, 130 V, 50 A, and 1600 r/min. Its field circuit israted at 5 A. The following data are known about the machine:160150140RA = 0.18 NRadj = 0 to 4O NVF = 130 VRp = 20 N130120Nf = 1000 turns per pole110Answer the following questions about this generator, assuming no armature reaction.10090(i)Determine the range of voltage adjustments that can be achieved by changingRadj if this generator is operating at no load.807060(ii) Analyze the maximum and minimum no-load voltages in the generator if the fieldrheostat is allowed to vary from 0 to 40 Q and the generator's speed is allowedto vary from 1400 to 2000 r/min.50403020(iii) Analyse the field current that must be flowing in the generator if the armaturecurrent of the generator is 50 A, the speed of the generator is 1500 r/min, and theterminal voltage is 106 V.10ok25Shunt field current, A1000200030004000500060007000Field mmf, A turnsFigure 4(c)Terminal and generated voltage, V

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The magnetization curve for a separately excited DC generator is shown in Figure Q4 (c). The generator is rated at 6 kW, 130 V, 50 A, and 1600 r/min. Its field circuit is rated at 5 A. The following data are known about the machine: (c) 160 150 140 VF = 130 V Rp = 20 N RA = 0.18 N 130 Radj = 0 to 40N Nf = 1000 turns per pole 120 T10 Answer the following questions about this generator, assuming no armature reaction. 100 90 (i) Determine the range of voltage adjustments that can be achieved by changing 80 Radj if this generator is operating at no load. 70 60 (ii) Analyze the maximum and minimum no-load voltages in the generator if the field rheostat is allowed to vary from 0 to 40 Q and the generator's speed is allowed 50 40 to vary from 1400 to 2000 r/min. 30 20 (iii) Analyse the field current that must be flowing in the generator if the armature current of the generator is 50 A, the speed of the generator is 1500 r/min, and the terminal voltage is 106 V. 10 ok 2 5 Shunt field current, A 1000 2000 3000 4000 5000 6000 7000 Field mmf. A turns Figure 4(c) Terminal and generated voltage, V

The magnetization curve for a separately excited DC generator is shown in Figure Q4 (c). The generator is rated at 6 kW, 130 V, 50 A, and 1600 r/min. Its field circuit is rated at 5 A. The following data are known about the machine: (c) 160 150 140 VF = 130 V Rp = 20 N RA = 0.18 N 130 Radj = 0 to 40N Nf = 1000 turns per pole 120 T10 Answer the following questions about this generator, assuming no armature reaction. 100 90 (i) Determine the range of voltage adjustments that can be achieved by changing 80 Radj if this generator is operating at no load. 70 60 (ii) Analyze the maximum and minimum no-load voltages in the generator if the field rheostat is allowed to vary from 0 to 40 Q and the generator's speed is allowed 50 40 to vary from 1400 to 2000 r/min. 30 20 (iii) Analyse the field current that must be flowing in the generator if the armature current of the generator is 50 A, the speed of the generator is 1500 r/min, and the terminal voltage is 106 V. 10 ok 2 5 Shunt field current, A 1000 2000 3000 4000 5000 6000 7000 Field mmf. A turns Figure 4(c) Terminal and generated voltage, V

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter39: Synchronous Motor Operation

Section: Chapter Questions

Problem 12SQ

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