EDUCATION

                        CONNECTION SCHEMES                                             OF                          DISTRIBUTION SYSTEM: CONNECTION SCHEMES OF DISTRIBUTION SYSTEM :                                           All distribution of electrical energy is done by constant voltage system. In practice the following distribution circuits are generally used. RADIAL SYSTEM :                                           fig 1.1                    In this system separate feeders radiate from a single Bub station and teed the distributors at one end only. Fig.1.1. shows a single line diagram of a radial system for A.C distribution. The radial system is employed only when power is generated at low yoltage and the sub station is located at the centre of the load.  Advantages :                        1. Simplest distribution circuit                         2. Lowest initial cost  Disadvantages :                        1. The end of the distribu

                   LAYOUT OF 110/11KV SUBSTATION: CIRCUIT DIAGRAM: THEORY : 1. The 3 phase 3 wire 110 KV feeder is tapped and brought to the Gang operated (GO) switch. The GO switch consists of isolators connected in each phase of the 3 phase line. 2. From the isolator the 110KV line is brought to the 110 KV Bus bar through Circuit Breaker (CB).  3. From the 110KV Bus bar, the 110 KV line is fed to the HT side of the 110KV/11KV stepdown transformer through Isolator. The transformer steps down the voltage to 11KV.  4. In fig.1.2. two 110/11KV transformers are connected from the 110 KV bus bar and the LT side of the power transformers are connected to the common 11KV Bus  through CB and Isolators. 5. From the 11KV Bus bar no of feeders are taken through  isolator and CB.  6. Lighting arresters are provided for protection from lightning and current transformers for current measurements. TAMIL VIDEO VERSION      :  https:

        RING MAIN BUSBAR:                                                fig.1.1            Fig.1.1 shows the arrangement of ring bus bar system. The ends of the bus bars are returned to form a ring. In this system each feeder is supplied from two paths. By a dopting this scheme of connections, the alternators connected to any one of the bus bar section can be used for supplying the load to the feeders on any section. ADVANTAGES :                           1. Each feeder is supplied from two paths.                            2. The arrangement is quite economical DISADVANTAGES :                           1.  The opening of any section of the breaker may cause overloading of the circuits.                           2. It is difficult to add any new cirouit to the ring                                      mp3 tamil version     TAMIL VIDEO VERSION :   https://youtu.be/dOpA37Ys6MU ENGLISH VIDEO VERSION:  https://youtu.be/Ktt8oaK0ivA

                                           DOUBLE BUSBAR                                                AND               DOUBLE BUSBAR WITH SECTIONALISATION  DOUBLE BUSBAR :  This system consists of two bus bars, one main bus bar and another auxiliary bus bar. The incoming and outgoing lines are connected to the two bus bars through circuit breaker and isolator. At normal condition, the incoming and outgoing lines are connected to the Main bus bar, and the auxiliary bus bar is kept as reserve bus bar. In case of repair or maintenance of main bus bar, the continuity of supply to the circuit can be maintained by transferring the circuit to the auxiliary bus bar. ADVANTAGES :                           1. In case of any fault on one of the bus bars, the continiuty of supply can be maintained by transferring the circuit to the healthy bus bar.                           2.Maintenance work can be easily carried out. DISADVANTAGES :          

                                            BUS BAR 1.                               SINGLE BUS BAR                 In this way, only one set bus - bar is attached to the entire generating station.  All transformers, generators and feeders are connected to this single bus - bar.  Generators are connected to the bus - bar via isolator and circuit breakers.  Similarly to incoming and outgoing feeders via isolator and circuit breakers are attached with bus bar. This system will suitable for both A.C and D.C ADVANTAGES:                         1.  Only one circuit breaker is required for each                              outgoing circuit.  So it's simple and cost effective.              2.  Since there are no transfer circuit breakers and                        disconnectors, the operation is simple              3.  The number of circuit breakers required is low.                        So the cost of maintenance is low.              4.  The potentia