Substation provides the energy supply for the local area in which the line is located. The main function of the substation is to collect the energy transmitted at high voltage from the generating station and then reduce the voltage to an appropriate value for local distribution and gives facilities for switching.
The substation is of two types one is the simple switching type where the different connection between transmission line are made and the other is the converting stations which convert AC to DC or vice versa or convert frequency from higher to lower or lower to higher.
The substation has an additional function like they provide points where safety devices may be installed to disconnect equipment or circuit in the event of the fault. The synchronous condenser is placed at the end of the transmission line for improving the power factor and for measuring the operation at the various part of the power system. Street lighting, as well as the switching control for street lighting, can be installed in a substation.
The single line diagram of an 11 KV substation is shown in the figure below. The single line diagram makes the system easy and it provides the facilitates reading of the electrical supply and connection.
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Skip to main content. Log In Sign Up. Download Free PDF. Ogungbure Semilogo. Project Supervisor Signature and Date Dr.
Ogungbure Zebulun O. Ogungbure Jimito S. I also want to appreciate my brother, Ogungbure Adesoji B. M and Pastor Arijesuyo A. A big thank you to my sponsors since the departure of my Mum in August, ,Dr. Sola Oladiran O. Ifedapo and Mr Dotun ,your presence in my life cannot be forgotten, I say thank you Sirs for your pieces of academic advice. My esteemed appreciation goes to my erudite, supportive and fatherly Project Supervisor, Engr.
I appreciate dearly your efforts and pray God bless all your endeavours Mr. Asonja B. D, I say a big thank you, for your motivation since my secondary school education.33KV/11KV SUBSTATION PRACTICAL EXPLANATION
And to the head of Electrical Department ,Dr. Oyetunji S. A, Dr. Ale T. O, for their understanding not just as my lecturers but also as fathers, I say thank you for all your coaching and for giving me the unmerited privilege to learn from you throughout my education in FUTA.
Indeed I would say I really enjoyed every bit of lecture you had with me. Charity they say begins at home, to this I wish to acknowledge my family for being the pillar of support for me throughout my 6 years on the land of FUTA 1 year PDS.The Key Diagram of Substation can be explained as under:. Such an arrangement of two incoming lines is called a double circuit.
Single Line Diagram of 11kV Substation
Each incoming line is capable of supplying the rated sub-station load. Both these lines can be loaded simultaneously to share the sub-station load or any one line can be called upon to meet the entire load.
The double circuit arrangement increases the reliability of the system. The advantage of double bus-bar system is that if repair is to be carried on one bus-bar, the supply need not be interrupted as the entire load can be transferred to the other bus.
There is an arrangement in the sub-station by which the same 66 kV double circuit supply is going out i. The outgoing 66 kV double circuit line can be made to act as incoming line. There is also an arrangement to step down the incoming 66 kV supply to 11 kV by two units of 3-phase transformers; each transformer supplying to a separate bus-bar.
Generally, one transformer supplies the entire sub-station load while the other transformer acts as a standby If need arises, both the transformers can be called upon to share the sub-station load.
The 11 kV outgoing lines feed to the distribution sub-stations located near consumers localities. Both incoming and outgoing lines are connected through circuit breakers having isolators on their either end. Whenever repair is to be carried over the line towers, the line is first switched off and then earthed. The potential transformers P. The P. The CTs are connected at the terminals of each circuit breaker. The lightning arresters are connected near the transformer terminals on H.
There are other auxiliary components in the sub-station such as capacitor bank for power factor improvement, earth connections, local supply connections, d.
The key diagram of this sub-station can be explained as under:. The 3-phase, 3-wire 11 kV line is tapped and brought to the gang operating switch installed near the sub-station. The G. From the G. It is fed to the H. The transformer steps down the voltage to V, 3-phase, 4-wire.
The secondary of transformer supplies to the bus-bars via the main O. From the bus-bars, V, 3-phase, 4-wire supply is given to the various consumers via V O.
You can change your ad preferences anytime. Substation overview. Upcoming SlideShare. Like this presentation? Why not share! Embed Size px. Start on. Show related SlideShares at end.Read about design of substation earthing system here.
The value of earth resistance of the ground system determines the voltage rise of the various earthed points during the earth fault. The permissible potential rise and the maximum possible earth fault current set a limit on the maximum value of earth resistance.
To achieve earth resistance within specified limits, enough number of earth spikes and sufficient surface area of the earth grid and closer ground mesh rods are necessary. The touch potential and earth potential in the switchyard under any earth fault condition should be within safe limits.
Substation Earthing System Design. Many thanks for this specific info on Earthing mat in substations. I was basically researching all Google in order to uncover it! Your email address will not be published. Remember Me. Not a member yet? Register now. Want to become an instructor? Are you a member?
Login now. The grounding system in substation is very important. The functions of grounding systems or earth mat in include:. In addition to such a grid below ground level, earthing spikes electrodes are driven into the ground. They are connected electrically to the earth grid, equipment bodies, structures, neutrals, etc.
All these are connected to the station earthing system by earthing strips. If the switchyards have a soil of low resistivity, earth resistance of the earthing system would be low.
If the soil resistivity is high, the mesh rods are laid at closer spacing. More electrodes are inserted in the ground. The fence, equipment body, tanks, support, structures, towers, structural steelworks, water pipes, etc. Earth Resistance Value The value of earth resistance of the ground system determines the voltage rise of the various earthed points during the earth fault.
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Such an arrangement of two incoming lines is called a double circuit. Each incoming line is capable of supplying the rated substation load. Both these lines can be loaded simultaneously to share the substation load or any one line can be called upon to meet the entire load. The double circuit arrangement increases the reliability of the system. In case there is a breakdown of one incoming line, the continuity of supply can be maintained by the other line.
The incoming lines can be connected to either busbar with the help of a bus-coupler which consists of a circuit breaker and isolators. The advantage of double busbar system is that if repair is to be carried on one busbar, the supply need not be interrupted as the entire load can be transferred to the other bus. Generally, one transformer supplies the entire substation load while the other transformer acts as a standby unit. If need arises, both the transformers can be called upon to share the substation load.
The 11 kV outgoing lines feed to the distribution substations located near consumers localities. Both incoming and outgoing lines are connected through circuit breakers having isolators on their either end. Whenever repair is to be carried over the line towers, the line is first switched off and then earthed.
The potential or voltage transformers PTs or VTs and current transformers CTs and suitably located for supply to metering and indicating instruments and relay circuits not shown in the figure.
The PT is connected right on the point where the line is terminated. The CTs are connected at the terminals of each circuit breaker. The lightning arresters are connected near the transformer terminals on high voltage side to protect them from lightning strokes.
There are other auxiliary components in the substation such as capacitor bank for power factor improvement, earth connections, local supply connections, d. However, these have been omitted in the single-line diagram for the sake of simplicity.
The 3-phase, 3-wire 11 kV line is tapped and brought to the gang operating switch installed near the substation.
The gang operated switch G. From the G. The transformer steps down the voltage to V, 3-phase, 4-wire. The single phase residential load is connected between any one phase and neutral whereas 3-phase, V motor load is connected across 3-phase lines directly.
The CTs are located at suitable places in the substation circuit and supply for the metering and indicating instruments and relay circuits. Hello sir, I would like to know that whether oltc transformerfis required at both levels i. The incoming line is 66lv and connected load is 15 mva. Pls, send to my mail your available write up on any part of electricity.
From 33kva down.
If we want to represent a three phase wire on SLD how are we supposed to do that? Does a single line with three strokes represent three phase line? Id like to see a basic line diagram of a primary school because the total kVA calculated seemed to be above Dear Mr. Kindly to check it and reply me as soon as possible.
Search for:. More Information.Premium Membership. Study specialized technical articles, electrical guides, and papers. The following layout designs of indoor distribution substation are typical only and should not be used as construction drawings as they are presented as an example. Some designs achieve minimum EMF emission by installing the low voltage cables and switchboard in a trench down the middle of the room.
This adds substantially to the space requirements. It is possible to reduce this space but only by sacrificing EMF containment!
The substations are designed for rated voltage 11 kV and kVA transformers. The space requirements for 22 kV padmount transformers need to be checked and it depends on manufacturer.
A drainage pit outside the substation is shown as optional. It can be installed if drainage is an issue or if needed to ease cable installation.
Each substation is unique and the space requirements shown in the sample layouts may not be available. It suggested to be mm after leaving breaker in racked out position or this is as in regulatory requirement as well. As per Indian Standards and, C. Safety Regulations and Rules ; there shall be minimum clearance between wall and equipment either less than mm or more than mm with height of not less than mm. What shall be the Fire Rating of Doors? Whether these transformers are Dry Type or Oil filled type?
If Oil filled type, what shall be the location in the building? Hi, I designed 2 rooms for 9 transformers one room contains 5 transformers and the second room contains 4 transformers of 1.
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