I have to measure, graph and display parameters of 3φ Induction Motor on a Graphic LCD at about 30 feet form the motor and transmit to a computer at about 60 feet from the motor to display it on VB application... The VB application should also be able to save one week record of the data sampled each hour, and display their graph at the end of week....
The parameters are....
1-Power factor
2-kW
3-kWh
4-kVA
5-Voltage
6-Current
7-rpm
8- Temperature
I hope I'll use PIC18F452...
->5 & 6 can be measured with PT and CT respectively--> Precision rectifiers---> 2 ADC channels
-->4th can be calculated with the help of above (VxI)
-> rpm with hall effect sensor or an optical one..
-> Temperature with DS1820 or LM35/34-->3rd ADC channel
-> 2 and 3 can be easily calculated if 1 is known(The only Problem I'm having)
We use 50Hz ac 440V 3φ supply in our country...
I really do not have any information on its harmonic content( Probably 3rd is more common here...) The motor is somewhere in steel mill.. with a heavy flywheel on its shaft..
Before final implementation I think I should make a test circuit for above specs with a single phase 220V,1KVA,50Hz Induction Motor.. and I will...
If you can provide information on the harmonic content, I can provide more specific design guidance.
I hope above info is sufficient for you to guide me....
Regards
Waqas Rafiq