A step-down chopper is to be used to supply power from a 600-V overhead wire to the commutator motor on a trolley bus. The motor may be mod- eled as a generated direct voltage in series with a resistance of 0.2 and an inductance of 25 mH. The frequency of the chopper is set at 500 Hz. (a) When the bus is stopped, what should be the ON time of the chopper to provide a motor current of 150 A? (b) What is the maximum possible generated voltage of the motor for which a current of 150 A can be supplied? (c) What is the average value of the supply current for the conditions of (a) and (b)? (d) If the motor current is to be continuous, what should be its minimum value?

A step-down chopper is to be used to supply power from a 600-V overhead wire to the commutator motor on a trolley bus. The motor may be mod- eled as a generated direct voltage in series with a resistance of 0.2 and an inductance of 25 mH. The frequency of the chopper is set at 500 Hz. (a) When the bus is stopped, what should be the ON time of the chopper to provide a motor current of 150 A? (b) What is the maximum possible generated voltage of the motor for which a current of 150 A can be supplied? (c) What is the average value of the supply current for the conditions of (a) and (b)? (d) If the motor current is to be continuous, what should be its minimum value?

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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