I am looking for a book formerly published by ABB. It was called "Testing of Power Transformers - ABB". If anyone has this book and find it useful, your comments will be appreciated. I haven't seen the book myself, but came across a reference about it on the internet. Where could I get an...
Could someone please explain the equivalent zero sequence circuit for a 2-winding Star/Star TX (HV ungrounded and LV grounded). The confusion is that PRAG shows that no zero sequence current will flow for ph-E faults. But, the J&P TX Book shows a link to the zero bus on the LV side. (I found...
What is the effect of a constant low voltage on a Induction Motor (constant Torque, 100Hp)? Tell me if I am wrong, but it will draw more current to compensate for the lower voltage, therefore more I(sqr)R Rotor losses and therefore more heat. Eventually the winding insulation will break down and...
Hi, All
Would appreciate some guidance on the following. I have the zero seq impedances (in ohms) for an auto TX. I would like to convert these values to p.u. for calculation purposes. I've seen formulas where they calculate Zoh, Zom and Zol. They then calculate Zbase and from there the p.u...
Assume a normal Star-Delta Automatic starter. I have seen in many text books that the connections to the Delta contactor is made from the supply side of the Main contactor. This means that these terminals on the Delta contactor are always live. Why not take these wires from the bottom of the...
Dear Omicron Users,
I wonder if any of you have successfully used the Advance Diff (Omicron) to test the T60 Transformer Diff relay. If any of you have an OCC file or maybe an XRIO for this relay, I would really appreciate it.
I managed to get good results for 3-ph faults, but less success...
We have two 132kV lines on the same towers for about 100km. In the past we have used a portable transformer and generator to test ZSMC on parallel lines by injecting around 140A on the one line, while the other one was first isolated and earthed, and with the next test un-earthed. Two setting...
