national grid and transformers Flashcards
what is the national grid
it is a giant system of cables and transformers that covers the uk and connects power stations to consumers, transferring electrical power to homes and industries when it’s needed
what is a base load
the minimum demand over a period of time
why do power stations need a short start up time
so they can quickly respond to the changes in demand
why do power stations run below their maximum power output
so there’s space capacity to cope with a high demand
how can the electricity supply become more reliable
by having smaller power stations that start up quickly just in case
what would happen if not enough electricity is avaliable or too much is produced
it’s imported from or exported to foreign countries
what is the problem with using a high current to transfer electricity and what is an alternative
huge amounts of energy is wasted as the wires heat up so it’s lost to its surroundings and an alternative is to use high voltage and low current
what does a transformer do
change the voltage
what are the 2 differences between a step up and step down transformer
1) step up increases the voltage whereas step down decreases it
2) the primary cord in a step up has more coils wrapped around whereas the secondary has less
how is the national grid reliable
the reliability is high as there are power stations nearby with a quick start up time therefore if the main power station has a problem and cannot generate electricity, the ones nearby can help. also electricity can be generated from abroad if needed
how is the national grid efficiant
the efficiency is high as there is a step up transformer which generates a high voltage but a low current in the cables. this means that less energy is lost and wasted and more is used where it is needed. this improves efficiency
how is the national grid safe
the national grid is very safe to use as after the electricity is generated through the cables, there is a step down transformer near the end to decrease the voltage and increase the current so before they are generated to houses buildings and industry, theyre safe. pylons also support cables high from the ground
