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# Power system calculator

Posted by yomgui | Feb 11, 2012 @ 08:09 AM | 3,932 Views
I've been working for a while on a power system calculator using data from propellers wind tunnel tests.

It is dedicated to electric power system.

http://aerotrash.over-blog.com/pages...r-6330077.html

# pictures of the wind tunnel

Posted by yomgui | Aug 27, 2011 @ 09:43 AM | 5,380 Views
Entrance cone of the wind tunnel:

Even the belt was not enough to curve the four parts in the right position!
The curve is simply parabolic function.
The entrance cone is kind of too short, but I needed place…

Inner side surface is not perfect.

# Tetacalc

Posted by yomgui | Jul 24, 2011 @ 05:22 PM | 3,888 Views
Here's my excel worksheet, using props data, and a "small" .doc file :

http://g.rouby.free.fr/tetacalc/tetacalc.rar

# Torque test bench for electric motors

Posted by yomgui | Jun 29, 2011 @ 11:03 AM | 7,216 Views
This homemade torque test bench gives very good results.

If the drive's resistance and no-load torque are known or well estimated, it allows to modelize a motor's performances with precision, based on amps, volts and rpm measurements.

Calculated values for power at the shaft are close to measured values, with an average error of 0,7% (max error = 3 %, but with the motor being run under bad conditions, with bad efficiency).

In fact, I think I can modelize a motor in a quite better way than only using amps, volts and rpm measurements (with kv thought as constant). BUT, it is very very close to any model taking into account inductance and to me it proves their reliability (thinking about drivecalc).

Well, I think...! I'm not at all a scientist...