Q8/A three-phase semi converter is used to control the speed of a separately excited d.c. motor rated at 100 kW, 600V, 2000 rpm. The converter is connected to a 3- phase 400 V, 50 Hz supply. The armature resistance is Ra 0.051 ohm and the armature circuit inductance is La = 10 mH. The motor voltage constant is Ke = 0.25 V/rpm. The rated armature current is 100A and the no load current is 10A. %3D With the converter operates as a rectifier, and assuming that the motor current is continuous and ripple-free, determine: (a) The no load speed when the firing angles: a= 0° and a= 60°. (b) The firing angle to obtain the rated speed of 2000 rpm at rated motor current.

Q8/A three-phase semi converter is used to control the speed of a separately excited d.c. motor rated at 100 kW, 600V, 2000 rpm. The converter is connected to a 3- phase 400 V, 50 Hz supply. The armature resistance is Ra 0.051 ohm and the armature circuit inductance is La = 10 mH. The motor voltage constant is Ke = 0.25 V/rpm. The rated armature current is 100A and the no load current is 10A. %3D With the converter operates as a rectifier, and assuming that the motor current is continuous and ripple-free, determine: (a) The no load speed when the firing angles: a= 0° and a= 60°. (b) The firing angle to obtain the rated speed of 2000 rpm at rated motor current.

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 12.4P

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