[subcooledheatpump]

I see, it appears you have a current transformer transducer. Sounds weird but it is different than just a hall effect current sensor. I actually had the same problems at first with my VFD but I had the opposite sensors.

I originally got what you need, a transformer/transducer. Turns out I needed a hall effect current sensor.

Keep us posted

[DDDvvv]

oh no. its also a hall effect current transducer. looks like everything from lem uses the hall effect principle. thats how they are able to sense dc current.

speaking of sensors, ups just delivered them. that was fast. ill get to test them later in the night.

[DDDvvv]

2012-05-12 00.29.16.jpg

2012-05-12 00.27.27.jpg

finally powered the contraption after a whole evening of checking and rechecking all the wiring.

i put my safety goggles on, turned on the power, set the drive to 2khz at volts/hz mode, and pressed the run button then started ramping up the speed.

motor kicked on and ran with no issues. makes a lot of noise at 2khz switch frequency.

after running it for a whole hour, i changed it to run under 4khz and the noise disappeared. ramped all the way to 60hz, with no issues.

the test motor is a 5hp with noisy old bearings, and no load. will resume tests tomorrow. i know this does not mean alot and the real test will be performance under load. but its a start.

anyone with ideas on how to load this motor will be really appreciated. im thinking of coupling the motor to a 3hp dc motor that i have, and applying a load to the motor as a generator.

[subcooledheatpump]

Congratulations, very exciting stuff to see.

I'd be a little leery about increasing the switching frequency any more than 4 kHz with those monster IGBTs while doing a load test. As I suspected you've got the current sensors I originally got and they didn't work.

Good to know, different drives take different types of sensors and now the EV community knows about hacking an allen bradley 1336 drive.

overall very impressive. I'll be looking forward to some load tests and also some readings of the IGBT temperatures and seeing your final cooling system

oh and for loading, this might work, might not depending on if the VFD needs the feedback noise of a motor to work; you could hook a 3 phase heater, or a bridge rectifier to the output and connect a resistor to the output of the rectifier for a load test. Certain VFDs I have will run just about anything, I even have a VFD running a metal halide light with an old motor stator as a ballast.

[PStechPaul]

Using the DC motor as a generator and driving heater coils seems like a good load. If you have an AC generator head, that's another option. And a big air compressor may also be good. It won't generate as much heat and you'll get useful work, but it's probably not a very constant load.

A datalogger would be helpful to record various parameters as a function of time. You can get some inexpensive data acquisition boards with 8 channels of A/D and software to take samples at regular intervals and then plot the results. And there are also USB digital storage scopes that can display the actual phase voltage and current waveforms.

I was going to do some power and torque testing on my custom wound motor, and someone warned me that I should be very careful. He suggested getting a heavy iron base with T-slots, as for a milling machine, and bolting down the motor and generator. Also recommended a blast shield. There is a lot of angular momentum in a fast spinning rotor and if it should jam the motor will tend to twist violently and may even explode. At least that's what seemed to be the danger. Good luck!

[aeroscott]

I'm looking of a cheap way to log wave forms , harmonics etc. I was thinking of a Math/Lab type free ware .Can you point me in the wright direction on these data boards .

[PStechPaul]

Originally Posted by aeroscott

I'm looking of a cheap way to log wave forms , harmonics etc. I was thinking of a Math/Lab type free ware .Can you point me in the wright direction on these data boards .

Here are some inexpensive packages:
http://www.dataq.com/data-acquisitio...arter-kits.htm
http://www.mccdaq.com/solutions/USB-...quisition.aspx
http://www.hytekautomation.com/Products/IUSBDAQ.html
http://labjack.com/products

and on eBay:
http://www.ebay.com/sch/i.html?_nkw=...cquisition+usb
http://www.ebay.com/sch/i.html?_nkw=pc+oscilloscope
http://www.ebay.com/sch/i.html?_nkw=pc+data+logger

You may be able to use your sound card for two-channel data acquisition.
http://hardandsoftware.mvps.org/sound_card.htm
http://www.tmworld.com/article/31970...plications.php
http://www.mathworks.com/products/da...edio14006.html

I am in the process of making my own. So far I have a PIC18F4420 driving an LCD display and 8 channels of ADC. They will read battery voltage and current, link voltage and current, joystick position, and temperature. The ADCs have about 150 uSec conversion time so they could be used to analyze waveforms. If you are looking at two channels at 60 Hz you could get 50 samples per cycle, and be able to see harmonics up to 1.5 kHz or so. You really need a DSO for that.

Also, if you need to log data over a long period of time (like a 10 minute run), you need a lot more data storage, and a fast way to transfer the data to a computer. I intend to sample the data I am concerned about at a rate of about 10/second, so if I want five channels the conversions will be 50/second. At 10 bits each, using RS232, you need 2 bytes per sample, and each byte takes 10 bits with 1 start and 1 stop bit. So that is 1000 bits per second, which is well below the usual default COM rate of 9600 bits/sec.

I have a proprietary product that takes samples at 2500 per second, to analyze a 60 Hz signal, so I am using 57.6 k baud rate. I store the data as 16 bit integers, so a typical test of 10 seconds results in a waveform file of 50 kB. A 10 minute run would be 3 MB. And that is for a single channel.

[Coulomb]

Originally Posted by DDDvvv

anyone with ideas on how to load this motor will be really appreciated. im thinking of coupling the motor to a 3hp dc motor that i have, and applying a load to the motor as a generator.

What would be ideal is if you can arrange for the DC generator to charge the DC bus. That way, you only need to supply losses from the mains or test pack, so you can run the motor at higher power. But you would have to be lucky to be able to get bus voltage from a DC generator.

[aeroscott]

Originally Posted by PStechPaul

Here are some inexpensive packages:
http://www.dataq.com/data-acquisitio...arter-kits.htm
http://www.mccdaq.com/solutions/USB-...quisition.aspx
http://www.hytekautomation.com/Products/IUSBDAQ.html
http://labjack.com/products

and on eBay:
http://www.ebay.com/sch/i.html?_nkw=...cquisition+usb
http://www.ebay.com/sch/i.html?_nkw=pc+oscilloscope
http://www.ebay.com/sch/i.html?_nkw=pc+data+logger

You may be able to use your sound card for two-channel data acquisition.
http://hardandsoftware.mvps.org/sound_card.htm
http://www.tmworld.com/article/31970...plications.php
http://www.mathworks.com/products/da...edio14006.html

I am in the process of making my own. So far I have a PIC18F4420 driving an LCD display and 8 channels of ADC. They will read battery voltage and current, link voltage and current, joystick position, and temperature. The ADCs have about 150 uSec conversion time so they could be used to analyze waveforms. If you are looking at two channels at 60 Hz you could get 50 samples per cycle, and be able to see harmonics up to 1.5 kHz or so. You really need a DSO for that.

Also, if you need to log data over a long period of time (like a 10 minute run), you need a lot more data storage, and a fast way to transfer the data to a computer. I intend to sample the data I am concerned about at a rate of about 10/second, so if I want five channels the conversions will be 50/second. At 10 bits each, using RS232, you need 2 bytes per sample, and each byte takes 10 bits with 1 start and 1 stop bit. So that is 1000 bits per second, which is well below the usual default COM rate of 9600 bits/sec.

I have a proprietary product that takes samples at 2500 per second, to analyze a 60 Hz signal, so I am using 57.6 k baud rate. I store the data as 16 bit integers, so a typical test of 10 seconds results in a waveform file of 50 kB. A 10 minute run would be 3 MB. And that is for a single channel.

Great thanks so much you saved me a lot of searching . DSO's that I've seen like the HP 54542, 500mhz , 4 channel , about $450-up but need to find if the data can be transferred to the computer without much hassle .I'll start looking over the links , thanks.

[Stiive]

Hi,
Great job so far. Just wondering if there's been any further progress?

I'm very interested in how you went with that capacitor bank? I'm looking at a metalized polyprop bank at a massive cost, but wondering how your DC bus ripple looks with that cheap eBay alternative. What is the capacitance you've ended up with there?