A 30-MW 10-kV Y-connected three-phase 60-Hz synchronous generator is connected to a grid. The gen- erator has six poles, and resistance and reactance of this generator are 0.1 Ohm and 0.75 Ohm, respectively. a) Find the speed of this generator both in rpm and rad/sec. b) Find the internal voltage (Ea) and generator efficiency (n) when it is supplying its full load at rated voltage and frequency with power factor of 0.85 lagging. Assume friction and windage losses to be 1 MW and core losses to be 800 kW. c) If the load of Part (b) is suddenly dropped, find the terminal voltage of the generator. d) When the load is 25 MVA at rated voltage with 0.80 lag. power factor, find the voltage regulation of the generator.

A 30-MW 10-kV Y-connected three-phase 60-Hz synchronous generator is connected to a grid. The gen- erator has six poles, and resistance and reactance of this generator are 0.1 Ohm and 0.75 Ohm, respectively. a) Find the speed of this generator both in rpm and rad/sec. b) Find the internal voltage (Ea) and generator efficiency (n) when it is supplying its full load at rated voltage and frequency with power factor of 0.85 lagging. Assume friction and windage losses to be 1 MW and core losses to be 800 kW. c) If the load of Part (b) is suddenly dropped, find the terminal voltage of the generator. d) When the load is 25 MVA at rated voltage with 0.80 lag. power factor, find the voltage regulation of the generator.

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

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.38P: Consider a three-phase generator rated 300MVA,23kV, supplying a system load of 240 MA and 0.9 power...

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