All the transformers I have seen that were hooked up to transmission had differential. The distance relaying I saw never saw through the transformer and we just lived with the fact that if a hard fault happened near the high side, both would trip. I don't think though that transformers when...
It is pretty hard to get your license revoked. You have to show either persistent willingness to violate the boards regulations or be negligent with fatalities. Being unethical and doing stuff like bidding on projects against your employer isn't enough. It is much easier to get sued though I...
You want low magnetizing current so that your measurements at low current don't have a lot of error. I suspect that they want you to get a low ratio CT, something like a 50/5 so the amount of current in your secondary circuit is large in comparison to the excitation current.
bacon4life,
This forum is extremely beneficial. I though wouldn't forget that there is a lot here that you wouldn't understand without having taken those applicable classes. We had potential interns (sophomores) try to answer a basic voltage divider with a resistor in series with two parallel...
Protolash,
A simpler solution would be to just remove the ground connection on the second set of wye-ground-delta transformers. I don't understand why they were ever grounded.
Honestly the most bang per buck for me has been in this order:
1. Try to find old people to talk shop with, online or offline. If you can't find people to talk shop with, you are only going to grow with the work you are given.
2. Being part of an industrial planning or standards development...
SEL relays often have a set of contacts that are high current interrupting and you often can get by without using an interposing relay. Utilities often don't want to use an interposing relay because it is a single point of failure. Some places don't even both with using high current...
Couldn't you just take that initial 700k offer money and hire a few hot shot engineers? The firm only has value as to what the customer perceives as adding value. Having hot shot engineers is the only thing that will add value and make it easier to get work.
Vter,
I think you want to get a copy of the IEEE Brown Book and IEEE 519. The brown book has a section in it explaining harmonics, how to model equipment, and how to mitigate issues. IEEE 519 has all the THD requirements for defining healthy voltages and currents.
When I did a study of a...
If you used relays for your MTM scheme, you will have all the functions you care about built into it and you can include protective functions into those relays as well. I am coming from a protecton background and not a controls background but I would use a relay for any function that involved...
The market can't and won't support nuclear power or even research into new reactor designs. There are so many other options now that are cheaper and don't require sunk cost for research. Even if there existed a potential nuclear power design that was economical, no one is going to fund the...
The angle shift is going to relate to how much inertia the system has. I read that most fast transfer schemes don't supervise sync so maybe this is usually a moot point but in Beckwith's materials and elsewhere, it is mentioned that fast transfer might not be possible depending on the system...
How do you determine the sync window for closing in on induction motors? I came across a motor standard stating that you don't want V/Hz to exceed 1.33 (IEEE C50.41-2000) but I don't really have a way of determining how the system voltage and frequency decays to know how small I need to make...
Each VFD has a profile based on how many pulses it has. You probably can get a pretty good idea of what harmonics the recifier produces based on how many pulses it has.
I don't know if you can back up what the harmonic currents will be based on the source impedance. You can have series and...
At least from what I have seen, a huge chunk of the spare capacity on the transmission system is for contingency. The NERC TPL standards demand N-1-1 contingency design requirements.
Waross,
I made it when I was growing up but it was pretty expensive at least for what I was paying for iodine.
I wanted to make mercury fulminate but never felt confident playing with mercury.
Usually it is to for a contingency case and not normal operations.
I did a study for a wind farm once that wanted to not have to upgrade their tape with the expansion of their wind farm with the reasoning that the line had a lot of extra capacity due only being able to generate when it is...
