1. INTRODUCTION Electrical subattribute for arrangement theory is the ocean minister to transform the violent voltage (HV) to low voltage (LV) and the settle where accuse are arranged to the consumers. In Malaysia, Tenaga Nasional Berhad Arrangement (TNBD) used the 33/0. 433kV, 22/0. 433kV, 11/0. 433kV and 6. 6/0. 433kV voltage theory for the electrical theory to minister for domiciliary consumer and industrial consumer such as factory which conciliate supplied immediately from Transmission Ocean Intakes (PMU), Ocean Arrangement Sub –attribute (PPU) or Ocean Switch Sub – attribute (SSU).
Electrical subattribute is the settle where all electrical equipments such as violent voltage switching, three sight transformer, violent voltage cables, low voltage cables, low voltage feeder shaft, battery charging and etc which are used for electrical ministering in dominion theory and to fashion unfailing the shieldion of the theory by the shieldion theory. Basically, electrical theory possess one or separate in coming and out going circumference which are inferior by violent voltage switching and converge in one or further in the selfselfsame of busbar theory.
Generally, electrical subattribute is a aim in arrangement theory where: * A settle where separate electrical equipments are inveterate and used for electrical ardor in dominion theory. * A settle where the shieldion of the theory is provides by automatically shieldion theory. * A settle where one or separate incoming and outgoing circumference are met at one or further busbar theory and inferior by violent voltage switching equipment which is used for switching. * A settle where voltage prize is transitional and inferior. A settle where accuse are arranged, inferior and armed FUNCTIONS OF A SUBSTATION * Minister of required electrical dominion. * Maximum likely coverage of the minister network. * Maximum shieldion of minister. * Shorordeal likely flaw-duration. * Optimum potentiality of plants and the network. 2. OPERATION OF 11 kV MODULAR POWER PLAN LAB Electric dominion is normally generated at 11-25kV in a dominion attribute. To despatch balance covet distances, it is then stepped-up to 400kV, 220kV or 132kV as expedient. Dominion is carried through a transmission netemployment of violent voltage lines.
Usually, these lines run into hundreds of kilometres and concede the dominion into a despicable dominion pool determined the grid. The grid is conjoined to accuse centres (cities) through a sub-transmission netemployment of normally 33kV (or casually 66kV) lines. These lines complete into a 33kV (or 66kV) substation, where the voltage is stepped-down to 11kV for dominion arrangement to accuse aims through a arrangement netemployment of lines at 11kV and inferior. The stepped-down voltage of 11kV is channelled to the RMU(Ring Ocean Unit) and outgoing feeder of the substation.
This is to enunfailing the continous minister of electricity plain during oceantenance. The RMU individual is speacially purposed that during oceantence the improbable users conciliate assent-to minister from a divergent subattribute which is interconnected. This is owing oceantenance possess to be carried out in an ON proviso. 3. BLOCK DIAGRAM OF 11kV MODULAR POWER PLAN 4. FUNCTIONS AND MAINTAINENCE OF ALL EQUIPMENTS 5. 1 Switch attribute/ circumference breaker In an electric dominion theory, switchgear is the confederacy of electrical misapply switches, fuses or circumference breakers used to moderate, shield and separate electrical equipment.
Switchattribute is used twain to de-energize equipment to concede employment to be effected and to clear faults downstream. This character of equipment is expressive owing it is immediately linked to the reliability of the electricity minister. Typically, the switchattribute in substations is located on twain the violent voltage and the low voltage border of catholic dominion transformers. The switchattribute on the low voltage border of the transformers may be located in a fabric, delay medium-voltage circumference breakers for arrangement circumferences, acovet delay metering, moderate, and shieldion equipment.
For industrial applications, a transformer and switchattribute line-up may be entilean in one housing, determined a individualized substation or USS. Types of circumference breakers: I. Oil Oil circumference breakers lean upon vaporization of some of the oil to explosion a jet of oil through the arc. II. Gas Gas (SF6) circumference breakers casually expand the arc using a magnetic room, and then lean upon the dielectric effectiveness of the SF6 to allay the expanded arc. III. Vacuum Vacuum circumference breakers possess minimal arcing (as there is rush to ionize other than the contiguity representative), so the arc allayes when it is expanded to a very narrow whole (<2–3 mm).
At or nigh present nothing the arc is not hot abundance to oceantain a plasma, and present ceases; the gap can then delaystand the mollify of voltage. Vacuum circumference breakers are frequently used in recent medium-voltage switchattribute to 35,000 volts. Unlike the other characters, they are inherently ungraceful for interrupting DC flaws. Defence 1) Visual Defence * To note the switchattribute to hinder any material mischief. 2) Insulation Ordeal * Should be less then 40 ? delay insulation opposition further than 100M?. 3) Change of oil. The oil in the switch attribute tank insufficiency to be replaced in a duration of season as it conciliate behove dirtier. 5. 2 Transformer A transformer is a dominion transformer that transfers electrical ardor from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary serpentine creates a varying magnetic flux in the transformer's kernel and thus a varying magnetic room through the secondary winding. This varying magnetic room induces a varying electromotive intensity (EMF), or "voltage", in the unweighty serpentine.
This issue is determined inductive coupling. Defence 1) Routine oceantenance * Effected uninterruptedly a week. Normal hinderout throughout the transformer. 2) Preventive oceantenance * For sight to sight or sight to negative,nsulation ordeal conciliate be effected by contrast prize of opposition further than 100M?. For LV to globe ,insulation must surpass 50M?. 3) Visual oceantenance * To note the transformer to hinder for any material mischief. 5. 3 Low voltage feeder shaft The low voltage feeder shaft comprises of the subjoined components : * Feeder Shaft Enclounfailing Busbars * Present Transformer * Deed Panel * Incoming Units * Outgoing Units Maintenence 1) Routine inadvertence. * Usually effected to hinder for unsophisticated completion and flaw. 2) Examination and advantage. * Do a unmeasured hinder up on all the deed in feeder shaft such as the misapplyors ,enclosures whether it is in good-tempered-tempered conditon or insufficiency to replaced. 5. 4 Cable Used to remove electric present for the HV and LV theory. At HV border, a 3 kernel cable is used time at LV border a 4 kernel cable is used. Maintainence 1) Visual inadvertence Note the RMU to hinder for any material mischief. 2) Continuity ordeal * To hinder if the present glide in the cable. 5. ELECTRICAL SAFETY RULES I. All elctrical equipment is to be inconsequent as in ON proviso. II. All the oceantenance employment should be effected inOFF circumference. III. Study FULLY encircling the deed antecedently effect or unquiet it. IV. Do not CLOSE any of the switch consistent you are common delay it and perceive how to moderate it whether in on or off proviso. V. Do not TOUCH any electrical ability or substance unleess you are not unfailing wheter the deed is DEAD and EARTHED.
VI. Do not misapply EARTHING relationship or return undignified the shieldion gadgets inveterate in the ocean apparatus. VII. Do not concede distrusted peculiar to feel HV electrical apparatus. 6. DISCUSSION Substations are separate of the electricity minister netemployment that enables the public use of electricity at home, employment, settles for order, ease, trade, soundness trouble, etc. The bulk of substations can be very fickle, depending on whether they benefit oceanly residential rightties, or to-boot commercial and industrial individuals, etc.
Schools and institutions such as hospitals frequently possess their own substation. There is a voltage colliquation in subattribute where 15kV-138kV the colliquation is 10 feet and 345kV is 18 feet. All oceantainence employmenters must exhibit right PPEs(Personal Protective Equipment) when entering the subattribute area. Substations are not dangerous owing they are substations. It is owing they are begirt by electromagnetic rooms that the equipment and cables they include product, that they possess to be treated delay timidity.
Measured electromagnetic rooms such as those productd by substations possess been associated delay soundness issues such as cancer, dip, dementia, barrenness, miscarriage, character completions, etc. There are two characters of electromagnetic rooms productd by balancehead and underground cables and the subattribute equipment itself; electric rooms and magnetic rooms. The effectiveness of the electric room depends on the voltage. Electric rooms from subattribute equipment are incredible to spread further the equipment housing, as they are screened by in-fact all fabric representatives.
Magnetic rooms are caused by electric present glideing when herd use electrical dominion. For all skilled purposes magnetic rooms cannot be stopped and conciliate pilgrimage through walls as if they were not there. There may to-boot be underground cables accidental to or far from the transformers. Electric and magnetic rooms to-boot follow from underground cables. The electric rooms conciliate be nothing as they are screened by globe, indurated, sand etc. The magnetic rooms are very violent nigh to the cable, violenter than from balancehead cables owing they are closer to you.
They droop off further expeditiously than the rooms from balancehead wires, owing the cables are closer concomitantly and erase out each other's issues further undeviatingly. 7. CONCLUSION The balanceall performance theory of a dominion subattribute is very expressive for electricity arrangement. Where it is to-boot expressive to minister dominion to users, it is to-boot expressive to enunfailing shieldion is statedly prioritized. All the equipments must rafter stated oceantenance to fashion unfailing they are employmenting rightly and thwart accidents. A log must be entered for each oceantenance effected so the narrative of the subattribute can be tracked. This to acceleration coming upgrades and for chronicles.