Group Assignment #2: Study Guide

Q1. Do Question No. 7 from Tutorial 1.

Q2. Do Problem No. 4.13-1 only, from PC Sen.

Q3. A 9 kW, 90 V, 1000 rpm, Ra = 0.1 Ω self-excited DC machine has a magnetization characteristic at 900 rpm as given in the attachment. The shunt field winding resistance Rfw = 100 Ω and the number of turns Nf = 1200 turns per pole. The rated field current If = 0.9 A. The machine is connected to a 90 V DC supply and is operated as a shunt DC motor. At no load conditions the motor runs at 1000 rpm and the armature takes 4.5 amperes. Repeat the same questions as in the Example 4.6, from PC Sen.

Q4. Do Problem No. 5.8, from PC Sen. Use the approximate equivalent circuit model of induction machine.

Q5. Do Problem No. 6.9, from PC Sen. Neglect armature resistance, Ra.

Q6. Explain the production of torque in a singly excited and a doubly excited electromechanical system.

Q7.  Explain how armature reaction occurs in DC machine

Q8.  Explain how to control a speed of DC motor.

Q9.  Explain the working principle of induction motor.

Q10.  Explain how a synchronous motor can control the power factor.