Grid Substation, Introduction, Grid station and National Grid substations

Grid Substation                                                            

  Introduction:

A grid substation is part of the electricity grid system -i.e. part of the transmission system. In the Bangladesh, this involves voltage levels of 400 kV, 230 kV, 132KV,66,11KV,  KV,440V,220V132 kV.Transmission of power occurs through the power distribution grid.
The latest technology that is used in power distribution is the 'smart grid'. It is nothing but digital technology which helps to assess the amount of power consumed and required in the future.

                                                                                                                                                                                              Grid station:

A 'grid' station is a substation -i.e. a compound or building containing transformers, circuit breakers, busbar systems, and protection system. The correct term is a 'grid substation', which is simply a substation which is part of the grid system -i.e. the transmission system. Other substations include 'primary substations', which interface the transmission system with the distribution system, and 'distribution substations' which could be as simple as a pole-mounted transformer. A pattern of lines on a chart or map, such as those representing latitude and longitude, which helps determine absolute location. Substations are where electricity lines are connected and switched and where the voltage is changed by transformers.  They range from the very large to the very small - see below for a guide.  But in nearly all cases, the highest field  is usually produced by the lines and cables supplying the substation and not by the equipment inside the substation itself. If the substation itself produces a field outside its perimeter, it usually falls away over the first few meters.

We give more detail of the fields from different types of substations.  In each case click on the picture for more details of the field it produces.

 National Grid substations:

Fig:3.1;These are large substations where 400 kV and 275 kV lines are switched and electricity is transformed down to the next voltage, 132 kV.
Sealing End Compounds

A sealing end compound is where an overhead line joins on to an underground cable.  It looks a bit like a small substation, surrounded by a metal fence, but does not contain any transformers or switchgear.

Fig:3.2; These are like National Grid substations but smaller and transform electricity between 132 kV, 33 kV and 11 kV.