Electric Motors and Control Systems
2nd Edition
ISBN: 9780073373812
Author: Frank D. Petruzella
Publisher: McGraw-Hill Education
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Chapter 2.5, Problem 5DT
To determine
The comparison between NEMA motor standards and IEC standards.
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QUESTION 8
Consider the equations of motion of an armature controlled DC motor given by
Jw(t)+bw (t) Ki(t) = -Tfriction - Tload (t)
di (t)
+ Ri (t) + Kw (t) =
Vin (t),
dt
where vin(t) is the input voltage and Tload(t) is the input load torque. The outputs are the armature current i(t) and the motor speed w(t).
The steady-state response of motors are specified by nominal voltage, stall torque, stall current, no load speed, and no load current.
At steady-state operation, the motor equations satisfy
bo) -Ki =-T -T.
fric
load
Ri +Kov_-
55
55
The stall torque is the load torque required stead-state speed of the motor is zero.
The stall current is the armature current when the motor speed is zero.
The no load speed is the speed of motor when the load torque is zero.
The no load current is the current when the load torque is zero.
What is stall torque for this motor in N-m? Keep 3 significant figures, and do not include units. Use Scientific notation.
The constants are given below.
Nominal…
Question 2
Beli vifth
Slack side
Motor
(imprut)
Tight side
Beli thickpess\
Centre distance
Figure 2
Figure 2 shows an open flat belt drive connected to a motor and a pulley. The
motor transmits 20 kw to the connect pulley of 450 mm diameter and is rotating
at 850 r/min to a second pulley rotating at 400 r/min. The distance between
pulley centres is approximately 2 m. The belt is 6 mm thick and has a density of
970 kg/m. The maximum stress in the belt is not to exceed 2,7 MPa. The
coefficient of friction for both pulleys is 0,3.
Determine:
2.1. The diameter of the second pulley.
2.2. The length of the belt.
3.3. The width of the belt taking centrifugal tension into account.
A 480V, 3-phase, 50Hz 6-pole Induction motor with a rated power of 10KVA.
(i) Calculate the synchronous speed in rad/sec (ws)
(ii) Determine the rotor speed in rpm, if the % slip is 2.5%
Chapter 2 Solutions
Electric Motors and Control Systems
Ch. 2.1 - Define the term motorcontrol circuit.Ch. 2.1 - Why are symbols used to represent components...Ch. 2.1 - An electrical circuit contains three pilot lights....Ch. 2.1 - Describe the basic structure of an electrical...Ch. 2.1 - Prob. 5RQCh. 2.1 - The contacts of a pushbutton switch open when...Ch. 2.1 - A relay coil labeled TR contains three...Ch. 2.1 - A rung on a ladder diagram requires that two...Ch. 2.1 - Prob. 9RQCh. 2.1 - The wire identification labels on several wires of...
Ch. 2.1 - A broken line representing a mechanical functionon...Ch. 2.2 - What is the main purpose of a wiring diagram?Ch. 2.2 - In addition to numbers, what other method can...Ch. 2.2 - Prob. 3RQCh. 2.2 - Prob. 4RQCh. 2.2 - Prob. 5RQCh. 2.2 - What is the main purpose of a single-line diagram?Ch. 2.2 - Prob. 7RQCh. 2.2 - Prob. 8RQCh. 2.3 - Prob. 1RQCh. 2.3 - Prob. 2RQCh. 2.3 - Prob. 3RQCh. 2.3 - Prob. 4RQCh. 2.3 - Prob. 5RQCh. 2.3 - Prob. 6RQCh. 2.3 - In what phase configurations are AC induction...Ch. 2.3 - Prob. 8RQCh. 2.3 - Prob. 9RQCh. 2.3 - Prob. 10RQCh. 2.3 - Prob. 11RQCh. 2.3 - Prob. 12RQCh. 2.3 - Prob. 13RQCh. 2.3 - Prob. 14RQCh. 2.3 - Prob. 15RQCh. 2.3 - Prob. 16RQCh. 2.3 - Prob. 17RQCh. 2.3 - Prob. 18RQCh. 2.3 - Prob. 19RQCh. 2.3 - Prob. 20RQCh. 2.3 - Prob. 21RQCh. 2.3 - Prob. 22RQCh. 2.4 - Interpret what each of the following pieces of...Ch. 2.4 - List three applications where a motor service...Ch. 2.4 - Prob. 3RQCh. 2.4 - Prob. 4RQCh. 2.4 - Prob. 5RQCh. 2.4 - Prob. 6RQCh. 2.4 - Prob. 7RQCh. 2.4 - Prob. 8RQCh. 2.5 - How are the contacts of a manual motor...Ch. 2.5 - Prob. 2RQCh. 2.5 - Prob. 3RQCh. 2.5 - Prob. 4RQCh. 2.5 - Prob. 1TCh. 2.5 - Prob. 2TCh. 2.5 - Prob. 4TCh. 2.5 - Prob. 5TCh. 2.5 - Prob. 6TCh. 2.5 - Prob. 1DTCh. 2.5 - Prob. 2DTCh. 2.5 - Search thelnternet forelectric motor...Ch. 2.5 - Prob. 4DTCh. 2.5 - Prob. 5DT
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