Answer / ajit g. k.

From thelimited amount of knowledge I have, I guess you are
meaning to know what a "black start" is. If thats the case,
I can explain to you what black start is.
A black start is referred to starting a power station from
an OFF position without the use of external energy sources.
The external energy source is mainly the power grid. In
some cases, there comes the problem that all the power
inputs to the grid may be disconnected due to wide area
outages. In that case, the power plant uses the 'internal
power sources' like diesel generators(DGs) which may be of
a rather smaller capacity. The DGs supply power for forced
draughts, controls and other auxillary requirements in the
power station.
Hope I have answered correctly. You may have read or
deciphered the question wrong. I have not yet heard of a
black star as a phenomenon or a process whatsoever in
electrical engineering. I would like to know if there is
something of that name.

Answer / naveenkumar(eee) g.k.m

Black around star is called as black star.............. For
Ex... You can see many Black star in sky with dull colour...:)

for a 500 KVA connected load, I calculated 30% of capactor for power correction. Even after using 225 KVR capactor PF is not improving. What could be reason for low Phase correction factor?

0 Answers   Power World,

---

How can we increase fuel-power ratio of any DG set?

0 Answers  

---

why VCB are not used in 132KV system(above 33KV system)

6 Answers   Al Ahleia,

---

what are the preventive maintanance actions taken for air circuit breaker? please answer me

0 Answers   MAHINDRA,

---

explain PV modules in solar energy generation.

0 Answers  

---

What should be the earthing resistance of an industrial substation and also What should be the house hold earthing resistance?

20 Answers   Jindal, Pharma, TAAT, TATA,

---

Explain the working principle of Synchronous Generator and Assynchronous generator?

11 Answers   TATA,

---

solar inverters was not connected to the nuteral link .this nutwral possible to any other systems

0 Answers  

---

what is the significance of cabability curve of alternator

0 Answers  

---

1)What will happen when 240 VDC supply is connected to 240VAC supply(DC supply +ve is connected to phase of AC supply & DC supply is to neutral of AC supply). 2)Also what will happen when 240 VDC supply is connected to 240 VAC supply in reverse polarity as of Sr. No 1.

2 Answers  

---

which one is dangerous AC Power r DC Power for Electrical Shock ?

10 Answers  

---

Why ground terminal is used in pot meter 10k ohms

0 Answers   Mahle,

---