Problem # 1: A four-pole DC machine has a wave winding of 300 turns. The flux per pole is 0.025 Wb. The DC machine rotates at 1000 rpm. a) Determine the machine constant, b) Determine the generated voltage, c) Determine the kW rating if the rated current through the turn is 25 A. Problem # 2: The following information is taken from the nameplate of a separately-excited dc generator. Armature: 120 kW, 600 V, 0.15 Q. Field: 100 V, 6.0 A At its rated speed of 3600 rpm the no-load torque is measured at 16 Nm. Ignore armature reaction and magnetic saturation. a) For rated load conditions determine: i) Rated Shaft Horsepower ii) Rated Efficiency iii) Load Impedance b) Determine the terminal voltage, kW output and the efficiency if the field current is reduced to 4.5 A, and the speed is reduced to 3000 rpm, causing the rotational losses to become 4 kW. The load impedance is unchanged.

Problem # 1: A four-pole DC machine has a wave winding of 300 turns. The flux per pole is 0.025 Wb. The DC machine rotates at 1000 rpm. a) Determine the machine constant, b) Determine the generated voltage, c) Determine the kW rating if the rated current through the turn is 25 A. Problem # 2: The following information is taken from the nameplate of a separately-excited dc generator. Armature: 120 kW, 600 V, 0.15 Q. Field: 100 V, 6.0 A At its rated speed of 3600 rpm the no-load torque is measured at 16 Nm. Ignore armature reaction and magnetic saturation. a) For rated load conditions determine: i) Rated Shaft Horsepower ii) Rated Efficiency iii) Load Impedance b) Determine the terminal voltage, kW output and the efficiency if the field current is reduced to 4.5 A, and the speed is reduced to 3000 rpm, causing the rotational losses to become 4 kW. The load impedance is unchanged.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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