Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
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Chapter 27, Problem 1RQ
To determine
Identify why and which voltage must be used for the dual voltage motor to be used for part winding starting.
Expert Solution & Answer
Explanation of Solution
If a dual voltage 240/480V motor is used for a part winding starting, then the low voltage setting must be used. This is because, since only one winding is connected to the power line, the high current due to high voltage supplied causes overheating of the windings.
Hence, 240V must be used for part winding starting.
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Q1.Given the unity feedback system with a forward path transfer function,
G(s) =
=
K
(s+1)(s+2)(s+6)
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(b) Find the gain, K, and natural frequency for a damping ratio 0.5.
(c) Find the range or value of gain, K for
i. overdamped ii. critically damped iii. Undamped iv. underdamped
Q. 1: The partial Routh array of a unity feedback system is given below.
S6
1
Adel
8
S5
1
S4
2
Bash
6
-4
0
C
0
How many roots does it have in the right half plane? Comment on the
stability of the system. Determine the characteristic equation of the system.
Q.2: Find the values of Ki and K2 for the system shown in the figure below
when Mp=0.25% and tp= 4 sec. assume unit step input.
R(S)
K₁
C(S)
1+ K₂S
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EXAMPLE 1: A diesel engine is fitted with a turbocharger,
which comprises a radial compressor driven by a radial
exhaust gas turbine. The air is drawn into the compressor at
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is delivered to the engine at a pressure of 2.0 bar. The
engine is operating on a gravimetric air/fuel ratio of 18: 1,
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600°C and at a pressure of 1.8 bar; the turbine exhausts at
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turbine are 70 per cent and 80 per cent, respectively.
Calculate (i) the temperature of the air leaving the
compressor (ii) the temperature of the gases leaving the
turbine (iii) the mechanical power loss in the turbocharger
expressed as a percentage of the power generated in the
turbine. Using the values of : Cpair = 1.01 kJ/kg K, Vair = 1.4
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Chapter 27 Solutions
Understanding Motor Controls
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