I think there might be a decimal point in the wrong place with that calculation. 1000V / 1000kOhm = 1mA, not 1A. Which is a lot less heating in any problematic connector, and unlikely to give the type of unambiguous evidence of damage that 1-2 kW might.
This is a little misleading.
If the generators are connected to a common busbar, the frequency measured by VTs on the busbar or the on the feeder will for all practical purposes be identical. Generators might have different speed setpoints as part of a droop load-sharing scheme, but this does...
More information about what the OP is actually trying to achieve might be useful.
A ROCOF scheme would typically be for detecting when the generation and some of the nearby distribution network have already become islanded from the wider grid. They're only useful/effective if there is a...
Which version of the standard did you get that from? It doesn't match the my copy of the red book, which is the 1993 version (and I believe the still-current version), which show Xd" and Xd' headings on the opposite columns.
The charging current for 3km of 132kV cable should swamp the magnetizing current of the 56 MVA transformer. It should ruin your site power factor even when operating under load. Therefore, I'd be fairly sceptical of your load flow results showing the same power factor at the DNO and at the...
Taking lines out of service is still done in the UK--the retirement of synchronous generation and the addition of large amounts of inverter-based embedded generation has made high voltages an issue. Certain circuits are designated for voltage control.
Another utility that I previously worked...
Cut-out based reclosers are making an entry though... (for example, here)
With regards to the original question, I haven't come across cutout fuses above 200A. IEEE C37.42 only seems to have standard ratings up to 200A, so I suspect that this is what the holders are designed for.
Cheers,
mgtrp
What ratio are the primary CTs? If they're fairly high ratio (e.g., 200-1 or 200-5 are quite common) then a few amps difference between phases probably doesn't mean too much.
Cheers,
mgtrp
Be careful comparing the descriptions in the linked eng-tips post (explanations from waross) and the IEEE standard--I believe that waross's explanations largely relate to transformers with a wye-connected HV and delta LV (i.e., Ynd), while the IEEE standard is referring to transformers with a...
It's not perfect, but the nice folks at Basler have made an attempt at fitting the recloser curves already. If you hunt around on their website near the bottom of the 'Technical Resources' section of any of their protection relays, you should find it.
Cheers,
mgtrp
Do the protection relays provide any oscillography? That'd be the first place that I'd be looking for clues.
Neutral CTs don't usually produce false currents, even if misconnected, so I'd be wondering about the possibility of there being an open circuit on the HV side of the transformer...
Is the tertiary grounded via a reactor, or is that a shunt reactor connected in the tertiary (the '4' next to it makes me think three phases plus a fourth on the star point)?
Cheers,
mgtrp
Assuming that there's no parallel feed transformers or zero-sequence sources on the LV distribution network, the LV CTs should only see fault current for a faults that are downstream of them (not on the transformer). But, if the fault is downstream of the CTs, then the differential should not...
