Summary is. It is the % of terminal voltage required to be applied on one side ( Primary) of the winding in order to circulate full load current on other ( Secondary) when other side is solidly short circuited.
A phase sequence change at the power input terminals could cause a problem.But the result will be erratic firing. It is hard to believe that a wrong phase sequence could take the excitation to ceiling conditions. It could simply be that 0% & 100% could be due to reversal in...
What was your overvoltage protection doing when voltage shot up to 1.5V.
The 10% power drawn is due to overexcitation of generator. It is common.
This is purely an AVR ( Excitation system problem). If PMG output voltage signal is reversed AVR can produce excess excitation. It has a blocking...
Should you have mentioned about voltage variation simultaneously, the subject would have been more clear. However, voltage remaining same, you will be slowly killing the rotating machines and transformer connected to this supply due to overfluxing of most of the equipment. However, in case of 51...
It is very difficult to estimate excitation current for old generators as provision of airgap in old machine was very liberal. Simple way is to check the panel meters if they are available luckily at original site. For a similar generator we encountered the field current was 140A at 56V. But it...
Irrespective of grid or isolated operation, set your relays to 115% and 85% inverse characteristics for O/V and U/V respectively. Check with your type of connected load for time setting.
I agree with Mr. bulsara. Based on our practical experience, system studies, voltage drop calculations during starting , network strength and cable sizing you can not have motor more than 250HP.
Yes it is available in the market. It operates on capacitive devider principle. There are three HV tester sticks to which the phase sequence meter is connected at end.Due to capacitive devider the voltage at the meter is hardly 100 to 150V AC. The sticks designed for lower voltage should not be...
A maintenace thumb rule is, highest system voltage plus 1 Mohms. If you are measuring IR of 11KV system phase with 5KV megger then you should have HSV+1= 12+1= 13Mohms to arrive at a firm decision to apply normal voltage to equipment ( charging).
