There will be about 6 assignments throughout the course. Some assignments will require use of Matlab/Simulink.
The Problems are given assuming (2012) 2nd Edition of the textbook.
Assignment 1: Due in class on Thursday, Jan. 23
Follow through Example 1A, and do Study Problem, SP1.2-2, SP1.2-4
Follow through Example 1B, and do Study Problems SP1.3-1, SP1.3-3
Follow through Example 1D, and do Study Problems SP1.5-2 and SP1.5-3.
Textbook Chapter 1 Problem(s): 3, 8, 9, 15, and 16.
Assignment 2: Due in class on Thursday, Feb. 6
Follow through Example 2A and 2B, and do Study Problem: SP2.3-3
Textbook Chapter 2 Problem(s): 4, 7, 13, 14, 18, and 19.
Assignment 3: Part 1: (Two Parts) Due in class on Thursday, Feb. 27 (together with Lab-2 Reports)
Follow through Examples 3A, 3B and 3C. Do Study Problems: SP3.4-1, SP3.4-2, and SP3.6-2.
Textbook Chapter 3 Problem(s): 1, 2, 7.
Problem A: Consider a 100V series DC motor. The motor consumes 100W at full load while operating at speed of 2000rpm when it is supplied from nominal voltage of 100V.
The armature and field winding resistances are: Ra = 2 Ohms and Rf = 1 Ohms, respectively. Calculate the stall torque (or the maximum starting torque) of this motor.
Problem B: Develop the time-domain block diagram for a series-connected dc machine. You will also need this for Part 2 of this Assignment.
Stepper Motors: Due in class on Thursday, Mar. 5
Do Study Problem: SP9.2-2, SP9.3-1, SP9.3-2, SP9.4-2, and SP9.6-1
Textbook Chapter 9 Problem(s): 1, 2, 5, and 8.
Assignment 5: Due in class on Thursday, Mar. 19
Synchronous Machines: Do Study Problems: SP7.3-2, SP7.4-1, SP7.4-3. Also, do the examples 7B and 7C (absolutely vital), and SP7.7-4.
Textbook Chapter 7 Problem(s) - 3, 9, 10, and 11.
Assignment 6 (2 parts): Due in class on Tuesday, Apr. 7
Assignment 6, Part 1: Use the Matlab/Simulink and develop a model of the 2-Phase Brushless PM Motor:
Vdc = 6 V (rater – nominal voltage); Lms = 10.1e-3H; Lls = 0.1e-3H; Rs = 5.2 Ohms;
J = 2.12e-6; Dm = 6.04e-6 N*m*s; Lamda_m = 1.65e-2 V*s/rad;
Nominal load torque: Tm = 3.53e-3 N*m;
Implement the following study:
Start the motor with zero initial conditions. At time t = 0.5 sec, apply the constant nominal torque to the motor shaft. Use the step function Step that can be found under the Sources in the Simulink Library.
You should observe the start-up transient followed by the response to the applied mechanical load.
Change your model such that it implements the 3-Phase Brushless PM Motor with otherwise the same parameters, and repeat the study. You will need to use eq. (8.13-5) – (8.13-7) to implement the correct phase voltages with 6-step waveforms.
Comment on how similar/different this motor response to the Series and PM Brushed motors modeled earlier.
Assignment 6, Part 2: Do Study Problem: SP6.2-2 and SP6.2-3; SP6.8-4, and do the Example 6C (this will help you for the Lab-5!) and Example 6D. Textbook Chapter Problem(s): 15 and 21.
Consider a 25hp, 3-phase, Y-connected, 220V line-to-line, 60Hz Induction Motor NEMA* Type B. The motor operates at full nominal load and the following is known: input electrical power Pe,in = 20.8kW; output mechanical power Pm,out = 25 HP; stator phase current Ias = 64A (rms); motor shaft speed n = 830 rpm. Establish and/or calculate the following:
a) Number of magnetic poles P
b) Actual electrical frequency of the rotor currents fr (assuming stator frequency fs = fe is 60Hz)
c) Input power factor pf as seen by the source
d) Mechanical (load) torque Tm
e) Motor efficiency under the given load