|
Why umbrella? Is it
because the high voltage transmission links are protected against the bad
weather by huge umbrellas?
No, of course! |
In
fact this site deals with the way the short circuits are detected on the high
voltage overhead lines. What more simple? You have in your house, as
everybody, a circuit breaker which trips thanks to over-current detectors
if, when you are tinkering on your electric installation, you make
wires touch together, or if a wire in your washing machine touches the tin,
or if you install too many electric apparatuses. We have only to do the same
on the high voltage lines. After all, it is always electricity! |
Not so simple! Firstly the voltages and
currents running on the described lines are much higher than in your house:
up to 400 000 V and 4 000 A, versus 220 V and 30 A (or a little more if you
have an electric heating) in your home. So it is no more possible to make the
detectors work with such data, but you must use reducers giving of them an
image as accurate as possible, but in a reduced scale.
Then, as there is in your house only one
wire which comes in and another which comes out, on the high voltage links
there are three wires, or three bundles of wires, run by different voltages.
More, when in your home the energy comes always from the outside, it may flow
here indifferently in one sense ore in another, depending on the mood of the
great sorcerers which manage the network. Finally the people who operate the
circuit breakers cannot see what happens on the line, and must however avoid
accidents |
|
All this
leads to develop some equipment, rather complicated to design, to
manufacture, to install and to set. For this, I created, to set the function
"distance protection" present on a number of them, a program named Umbrella. This is the
translation of a French abbreviation, but I like it as I like to walk under
an umbrella when it
rains. You not? So each time you see the word Umbrella written, or
you see a drawing or a picture with an umbrella, click on it
and you will change your opinion. |
||
|
|
And this abbreviation means
"Programme d'Aide
au Réglage des Appareils de Protections
de Ligne Utilisant l'Impédance Electrique" (program to help the setting of the line
protective relays using electrical impedance) |
|
|
This is a program
reckoning the setting of equipment situated on each end of an electric energy
transmission link,
...
otherwise, of the high voltage overhead lines which
embellish the landscape of our beautifull country;
These
devices make trip the circuit breakers placed on each end of these lines,
when a short circuit due to lightning or else, disturbs them. |
||
|
|
Is this quite clear for
you ? Probably not, and that is why I put on this website a book
explaining how the disturbances of all kind likely to appear on the French
network are cleared Why the French
network? Simply because it is the one I know the best. But each time I could,
I noticed how other networks are protected. |
|
|
(the transmission network is the whole
of overhead lines, underground cables and power transformers having in charge
the transmission of electrical energy from the power plants to the
20 000 V networks. These assets work under voltages from 63 000
V to 400 000 V on the French
network, and even 730 000 V on other countries, |
||
|
If all this does not
interest you, so good bye and
thank you for your visit. |
If you are interested,
here are the documents you will find : Ì Book" protection and
monitoring of the transmission network"
(this document contains
among others the presentation of the program umbrella in appendix 8, and its
guidebook in appendix 9) Ì Program Umbrella If you want more
explanations, contact me at:
|
|
If you do not find the further documentation, send me
a mail to the address above, with your own post address. I shall send you a CD
with the whole documentation.
I created this website in a total unpaid way.
If you want to gratify me, you can make a gift to
the association
SOS méditerranée
Thank you for them!