LionelHutz ,
You mentioned "torque limit",which parameter in the VFD is this "torque limit"? I did not see. VFD has a parameter called "Torque setpoint". I'm using two Relinace GV6000 drive. Also, when the dyno drive set as " FVC " control (Flux Vector Control), after give a start command, drive...
DickDV,
Thanks.
The motoring drive is already running at 50hz, then start the dyno drive , give the speed input of 50hz. That way, I will see a overcurrent faults.
Do you mean that both drives start together? I've tried this also, same overcurrent faults.
LionelHutz ,thanks.
1. Can I try this way: start test motor first. Dyno VFD setting: "flux vector control"/"torque regulation" (question: with encoder feedback or without"). Set speed reference at 0hz on the dyno VFD. I want to manally increase the load by vary "torque setpoint" parameter. Does...
DickDV ,
Thanks for your help.
I start the test motor first say at 50HZ, acel time 5s. After reach full speed, I start dyno motor at 50HZ, acel time 5s also. You 've seen the problem, the dyno motor won't ramp up to 50hz as the VFD OL alarm because the speed is not sync'd.
One point to note: the...
Hi all, finally i've setup this test plant.
I've tested today. I do not know how to upload my schematic drawing here? but principle is described here in this thread. Test VFD drives a test motor which is coupled with dyno motor driven by dyno VFD. A torque transducer is mounted between.
I...
After study, I finally found out actually there are 3 ways to doing a load testing at such back to back loading using two VFD supply.
Way #1.
In this case, both VFD drives using V/HZ speed regulation mode.
1.Start both test motor and dyno motor at same time, speed command at nameplate speed...
I'm having a question:
We are having some equipments in US which to be moved to China. There is a power supply difference:
US: 460V/60HZ
CHINA: 380V/50HZ
Searched a few articles about this equipments modifications. Any one here have any good suggestions?
NEMA does not specify all these detail information to be put on the nameplate for inverter duty.
DickDV is right, it's all manufacturer's interest to put detail info on the nameplate, normally medium and large size motors. Some manufacturers like "Reliance Motor", they put constant torque...
A hard copy has its advantage, let say on the bed you can read , it's convenient than pdf copy.
Sure, PDF can do "search","marking". I just like to have a hard copy one.
Can a traditional Current Transformer be used in a VFD application? Is it capable to read correct current? For example , 10 HZ, 20HZ .
A traditional Current Transformer I 've used normally works in a 50HZ application.
I come back to this thread again!
Is it possible to use Torque Control mode on the dyno VFD drive? Torque reference could be the torque reading from the torque meter mounted between dyno motor and test motor.
But I am wondering these:
When "actual torque"< "required torque", my dyno VFD should...
Norma 5000 (a Fluke company) is a good power analyzer, is it? I've searched the web, it sounds like okay to me, but not sure the price.
Yokogawa should be a perfect device , but it's extremly expensive.....
Hi CJCPE ?
I'll connect the two DC bus together with fast fuses in seires.
I still do not understand how to set a "negative control" for a VFD? If this could happen, my plan is to automatically test the load motor at 1/2,1/4,1,1.2 load ( load motor running at nameplate speed, while test motor...
What about a normal VFD? Do they have "negative torque control"?
As i know, a normal VFD has sensorless vector; V/HZ; Venctor control. All of above are "postive control" methods.
Torque control using torque signal from a torque transducer is needed.
What I am wondering is when the torque reads 50% x Full load torque ( we want to load the test motor at 100% full load ), dyno VFD will try to speed up. But, actually in this case we want dyno VFD to speed down to increase...
