# hw11 - voltage source consider the situation if the machine...

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EE321 Spring 2008 Homework 11 Problem 47 – QD Transformation Starting with abcs T abcs cs cs bs bs as as i v i v i v P i v = + + = Show that ( ) s s r ds r ds r qs r qs i v i v i v P 0 0 2 2 3 + + = Problem 48 – Brushless DC Operation from a Voltage Source A three phase brushless DC machine has the following parameters: Ω = 3 s r , 10 = ss L mH, 17 . 0 = m λ Vs, 4 = P . It is operating from an inverter and the control is such that 100 = s v V (rms) and 0 . 0 = v φ . The load torque is given by 3 . 2 ) 200 / ( 2 rm l T ω = . Find the steady-state rotor speed in RPM, and the magnitude of the stator current. What is the efficiency ? Problem 49– Brushless DC Operation from a Current Source Consider the machine in Problem 49, with the same load torque. Instead of being supplied from a
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Unformatted text preview: voltage source, consider the situation if the machine is supplied from a current source (with all the current in the q-axis). Plot the rms current, rms voltage, and efficiency of the machine as the speed is varied from 0 to 4000 RPM. Problem 50 – Brushless DC Parameter Identification A three-phase brushless dc machine is open circuited, and is spun using a dynamometer. The a- to b- phase voltage measured from an oscilloscope if found to be sinusoidal. The waveform has a peak-to-peak voltage of 200 V, and a frequency of 82 Hz. What is m ?...
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## This note was uploaded on 09/22/2011 for the course ECE 321 taught by Professor Staff during the Spring '08 term at Purdue.

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