Operation and Commissioning of 33/11 kV Power Substation

This thesis report is prepared in according to the operation and maintenance procedure of 33/11KV Substation, including emergency maintenance work.

This is a switching sub-station from where Dhaka Palli Bidyut Samity -1 and other PBSs are controlled. It has thirteen feeders from which different PBSs are fed. Actually, it is consists of a feeder controlling room and a switching yard.

All controls such as line current for each feeder, and line and phase voltage for each feeder are measured by much Low Tension (LT) panels and High tension panels (HT). The switchyard is the place where the actual equipment is working properly.

This switching sub-station has mainly consisted of two parts. The main components are described below briefly:

This is a large place where switchgear components are paced according to the one-line diagram which is provided by an experienced electrical engineer after electrical calculation.

In Sub-Station, it is often desired to disconnect a part of the system for general maintenance and repairs. This is accomplished by an isolating switch or isolator.

!!! An isolator is essentially a knife Switch and is design to often open a circuit under no load, in other words, isolator Switches are operate only when the line is which they are connected carry no load. For example, consider that the isolator are connected on both side of a cut breaker, if the isolators are to be opened, the C.B. must be opened first.

If an isolator is opened carelessly, when carrying a high current the resulting arc easily causes a flashover to earth. This may batter the supporting insulators & may even cause a fatal accident to the operator, particularly in the high voltage circuit.