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The power of one (mega watt)

I have done many things already, but recently someone asked me to find a way to automatically test and report findings on very large Diesel generators.
The project involves building a portable (with a crane) setup for testing the performance of generators upto a power of about one MegaWatt. (MW)
For me that is a lot of power. 
The test involves increasing the power output stepwise and measuring the response of a generator, including Current, Voltage, Frequency, Power factor and Temperature. 
I have taken a picture of the resistor array we apply to consume this much power from the generator.
The resistor array has forced air through it, and can take about 3 x 1500 Amps at 400 Volts.

The plan for now : Laptop with RS485/Modbus to the control- and measurement- equipment.
Possibly linux as the OS to prevent tinkering, security, driver and update issues.
update 2013/6/13 : I already wrote python program to control the measurement module ( Diris A10 over modbus RS485)
update 2 : I am now looking for some nice control modules (I found these, http://www.temcocontrols.com/products/controllers/22/t3-series-modules.htm ) but not sure I can get them locally.
I will get back to this project later with more details and pictures.

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