# hw6 - EE321 Spring 2010 / Homework 6 Problem 1 – Problem...

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Unformatted text preview: EE321 Spring 2010 / Homework 6 Problem 1 – Problem 3.10-3 from Electromechanical Motion Devices Problem 2 – Problem 3.10-6 from Electromechanical Motion Devices Problem 3 – PM DC Machine Performance A PM DC machine has a back emf constant of 0.1 Vs, and an armature resistance of 300 m Ω . The armature voltage is 25 V, and the load torque may be expressed 3 400 2 = r l T ϖ Find the rotor speed, the armature current, and the efficiency. Problem 4 – Separately Excited DC Machine A separately excited dc machine has a armature resistance of 0.2 Ohms, a field resistance of 4 Ohms, L af of 200 mH. We wish to determine the currents (armature and field) in such a way as to achieve a torque of 2 Nm, while minimizing the loss. What should the armature and field current be ? What will the machine loss be at this point ? Note: you may assume you are not against any voltage limits....
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## This note was uploaded on 04/08/2012 for the course ECE 321 taught by Professor Staff during the Spring '08 term at Purdue University.

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