national grid

[shakerbess]

hi could some one please tell me why the substation near the load centre of supply system and how this is an important factor in the efficiency of the system

Also why do they have high voltages at different points of the distribution system and how his improves efficiency of the system

hope some body could help

 

[snowhead]

Try, Transmission Losses.

 

[davesparks]

This sounds a lot like a homework question!

Best thing to do is tell is what you think the answer is and then we can help you t

 

[shakerbess]

This sounds a lot like a homework question!

Best thing to do is tell is what you think the answer is and then we can help you t

I believe that the substation is situated close to the panel boards used in commercial and residential so that the losses are reduced due to heat and the system would be more efficient overall less cable also used.

The voltages re stepped again to reduce the loss due to heat generated via current to counter act this the current is lowered and the voltage is stepped up at various parts along the national grid to reduce transmission losses

 

[Engineer54]

I believe that the substation is situated close to the panel boards used in commercial and residential so that the losses are reduced due to heat and the system would be more efficient overall less cable also used.

The main reasons a distribution TX is located close to it's main switchboard is cost and convenience. Think about it, having say a 1000 KVA TX located 100 to 200 metres distant from its switchboard, you would need to provide considerably larger and more cables from the TX to the switchboard, and you need to provide an installation route/means for those cables between the TX and MSB . It is not at all uncommon for TX's to be incorporated as part of the main switchboard. eg A matched pair of TX's mounted at each end of a bus coupled main switchboard, connected via short flexible bus bar connections....

I'll let others explain about why the different transmission voltages and transmission losses...

 

[shakerbess]

The main reasons a distribution TX is located close to it's main switchboard is cost and convenience. Think about it, having say a 1000 KVA TX located 100 to 200 metres distant from its switchboard, you would need to provide considerably larger and more cables from the TX to the switchboard, and you need to provide an installation route/means for those cables between the TX and MSB . It is not at all uncommon for TX's to be incorporated as part of the main switchboard. eg A matched pair of TX's mounted at each end of a bus coupled main switchboard, connected via short flexible bus bar connections....

I'll let others explain about why the different transmission voltages and transmission losses...

Thankyou for your time and reply mate

 

[Besoeker]

Shakerbess

As others have pointed out, higher voltage means lower current for the same kVA. This allows smaller (lower cost) conductors to be be used, lower losses, and lower voltage drop. For long transmission runs, these are all significant practical issues.

Just to add a little to this mix, high voltage dc transmission is being increasingly used. It isn't exactly new but improved semiconductor technology is making it more practicable. It has the merits of reduced cable impedance (the inductive component) so reduced voltage drop and fewer conductors. Installed systems are commonly above 500kV and 1,000 km or more long.

 

[Knobhead]

In urban areas 1000KVA transformers are commonly used. The input current at 11KV is only 53A the output at 433V is 1333A. The output needs a hell of a lot of copper.