For the record so far. It was determined that if we only ran 1 generator (remember this is an offshore rig), there was a KVAR spike on the generator the same time we went into imbalance, and KW dropped at the same time. It was also determined that if we had two generators online, an imbalance...
Thank you all for you comments, good stuff here. The additional 7.5 degree is added in to make it a 24 pulse harmonic cancellation. I do not know how the 7.5 degrees is implemented at the HV transformer. Our company is asking the manufacturer for information (which I probably will not get in the...
KRSH,
The drive is oerating in encoderless vector, but what I mean is when we reduce the frequency to some lower level. The motors are 40HZ 788rpm 600V. We drive these to a about 150% of rated Hz, it appears that the problem arises after 40hz, and this imbalance stays when we lower the Hz back...
Dear Readers~
We have a VFD rectifier that has two bridges on it. One bridge is fed from a delta connection and the other from a Wye connection. The idea is to provide harmonic cancelation for a VFD system. We did not originally have input line reactors and the fuses to the rectifier Y bridge...
Team,
I'm trying to develop a mathematical relatiionship for the HP(or KW)for a Motor controled by a VFD. The motor is a 1150 HP 600VAC, 40 HZ 6 pole motor. I have a theoretical model showing a linear relationship from 0hz to 40hz. HP is constant to a point after that, I know. I'll have...
Ok Thanks people. aside from the calculations I did to show savings. We had our power company come and talk about "Focus and Energy" They will foot the bill to install up to %30, which in this case was about 120,000. They also will foot %50 to have an outside source evaluate the application...
Thanks Guys, Ok, Here is what I inititally intended to do to save money. As you say, ther are possible considerable savings by varying the speed. This dust collection unit closes a damper to pulse what amounts to vacuum bags and knock the dust off of them. They know when to pulse by differential...
I've been doing some research for my company and have to present how much I can save the company by going to VFD's instead of direct induction (starter application). I don't get the option of a test bench or wind tunnel, so please help me if you can. We have approx. 36 fan applications, dust...
