Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Chapter 46, Problem 4RQ
What solid-state device is generally used to produce variable frequency in drives designed to control motors up to 500 horsepower?
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Consider the power drawn by a resistance load in a DC circuit. The power is calculated as P = VI or P = 1²R. It is
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A piston–cylinder device contains 3 kg of nitrogen initially at 100 kPa and 25°C. Nitrogen is now compressed slowly in a polytropic process during which PV1.3 = constant until the volume is reduced by one-half. Determine the work done and the heat transfer for this process. The gas constant of N2 is R = 0.2968 kPa·m3/kg·K. The cv value of N2 at the anticipated average temperature of 350 K is 0.744 kJ/kg·K (Table A-2b).
The work done for this process is kJ.
The heat transfer for this process is kJ.
Chapter 46 Solutions
Industrial Motor Control
Ch. 46 - Prob. 1RQCh. 46 - Prob. 2RQCh. 46 - If an alternator is used to provide variable...Ch. 46 - What solid-state device is generally used to...Ch. 46 - Why are SCRs used to construct a bridge rectifier...Ch. 46 - What is the main disadvantage of using SCRs in a...Ch. 46 - How are junction transistors driven into...Ch. 46 - What is the disadvantage of driving a junction...Ch. 46 - Prob. 9RQCh. 46 - In variable frequency drives that employ IGBTs,...
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