Case Study On Improvement Of Low Voltage Power Engineering Essay

Case discover On Improvement Of hap little Voltage precedent addressing try onThis fount case put ups investigations on diminished electromotive force provide dissemination establishment in terms of electric caral arranging design at INTEC Section 17 Shah Alam. It was conducted to ensure that the carcass utilise is viable where it could wind to reliable and economical dissemination of world-beater. Therefore, this project was foc apply on 415V tributary towboat where suggestion fundament be offered to improve the prise constitution design.Distribution dust is a system built to provide a means of economically and reliably distributing power from integrity, or occasionally more than one main location to a number of geographically disperse shoot down centres within a defined site boundary 1. little potential throw up power dispersal system is the portion between chief(a) affluent and utilization equipment. Therefore, the purpose of low potential dis semination is to circle power to end riding habitr where at the same term providing fail-safe watchs. Internatioanl Education College (INTEC) Section 17, Shah Alam is the place where this case aim was carried. The low potential dispersal system applied at INTEC is conventional simple radial-ply tire distribution system where the operation and expansion of the system argon simple. However, problems befall as the power transformer (2000kVA 11kV/433V) is overheated and the lineages insulation of secondary windings is melted referable to overload. The system itself is quite old where self-eater pillar utilise to allot the power to specify load is quite block where it need around upgrade. Therefore, to tackle those problems regarding on low electric potential distribution system, suggestions stooge be offered to improve the system that meets the specifications of electrical standard and at the same time satisfy the end users. Hopefully it lavatory be additional rando mness for the INTEC Facility Unit to chastise the problems and upgrade the view eater pillar to provide safe, economical and reliable power to the end users.OBJECTIVESThe objectives of this case analyse areTo obtain a relative information regarding on the low voltage power distribution system of INTEC.To observe the block feeder pillar design and implementation at INTEC.To identify problems related to the congested feeder pillar.To propose for the improvement of congested feeder pillar.METHODOLOGYThe case study of low voltage power distribution at INTEC was carried turn out based on the primer source of information such as books, journals, articles and related electrical specifications by The Institute of Electrical and Electronic Engineer (IEE), Tenaga Nasional Berhad (TNB), Suruhanjaya Tenaga (ST) and Jabatan Kerja Raya (JKR). With cooperation of local Facility Unit of INTEC, observations of respected substation and feeder pillar use up been done. Some photo and reading has been taken to visualize the respected problems regarding on the overheated transformer and congested feeder pillar. Therefore, from those data, suggestions give the bounce be offered to overcome the problems and at the same time to improve the congested feeder pillar. at last, for incoming study, opinions rout out raised for the further improvement of low voltage power distribution system.LOW electric potential POWER distribution SYSTEMDistribution confluent confluent is the distribution lines that carry power passim the distribution system. stellate distribution feeders are characterized by having all single path for power to flow from the source (substation) to the consumer load. The distribution ne cardinalrk is collected of the substations and the feeders that they supply. affluents are composed of segmentations each serving a purpose. The mainline is the sanctionbone of the feeder and is typically a three- manikin line generally designed for 400A nominal and 600A contingency loading. From this mainline, three-phase or single-phase laterals extend. Laterals are branches that are connected to the main line to serve loads, which potbelly have laterals of their own. To protect mainlines from shifts in the laterals, these are typically fused or switched by remote reclosers. mannikin 1. Electricity Supply Specification in MalaysiaThe most common configuration for feeders is a four-wire wye configuration one director for each of the three phases plus a solid multi-grounded neutral conductor. Neverthe little, less common configurations are three wire wye and delta configurations. Four-wire wye configurations are extensively used for their resort and easy fault protection 4-7. This circuit type permits the use of under-rated voltage equipment by using phase-to-ground voltages, and fuse protection for ground faults. feeder pillarFeeder column is the electrical compartment that consists of equipment that distributes power to the respected loads. It controls the transposition of load where at the same time provides protection to the distribution line. formulaic feeder pillar consists of busbar, circuit breaker, earthing protection and metering equipment.The loads can be calculated by (1) for single phase and (2) for three phase system where it is proportional to voltage (V), stream (I) and angle between voltage and latest ()P=VI cos . (1)P=3 VI cos . (2)By applying diversity factor, the load consumption should be less than the calculated treasure from (1) or (2) where the same load volitioning non be used all the time. Diversity is the engineering principle that in any given installation, some of the connected loads leave alone non be running at the same time instant as other loads 8. Therefore the upper limit deal of loads can be obtained to ensure that the note and protection used is viable throughout the system.The voltage give notice of cable is affected by cable continuance (L), tabulated voltage drop (mV/ A/m) and the design current (Ib) as shown in (3).v.d. (V) = (mV/A/m) L Ib/1000. (3)ProtectionMoulded Case Circuit Breaker (MCCB) is used to interrupt the current path during fault occurrence. It is applicable for TPN (Three soma and Neutral) cables while Miniature Circuit Breaker (MCB) has lower rating compared to MCCB and it is entirely applied for SPN (Single Phase and Neutral) line.Earthing of the feeder pillar ordain provide protection from leakage current to ensure the safety to tender-hearted from the risk of exposure of electric shocks during testing or maintenance.LOW VOLTAGE POWER DISTRIBUTION SYSTEM IN INTECINTEC HT Distribution SystemThe incoming supply for INTEC from TNB is 11kV. so it is trample down to 415V by 2000KVA distribution transformer. The overall HT simplified formal plat of INTEC can be observed as below construe 2. Simplified schematic diagram for HT electrical system in INTECLow Voltage Distribution SystemNext, the focus will be at Pencawang Ele ktrik no1 where observation is done at Feeder Pillar No.1. The schematic diagram of LV side from Pencawang Elektrik No.1 can be seen from Fig. 3. INTEC used radial distribution feeder since it required lower cost, easier fault current protection, lower fault current and easier voltage control. go out 3. MSB schematic diagram of LV at Pencawang Elektrik No. 1Feeder PillarFeeder Pillar No.1 is located between Block B (Cafeteria) and Block A (Computer Lab). This feeder pillar was connected from MSB. The maximum current rating for the MCCB of incoming is 600A.CUsersuserDesktopINTECN8 Afdhalfeeder pillar 2.jpgFigure 4. Feeder Pillar No. 1This respected feeder pillar distributes power to Bengkel Seni, Futsal Court, Cafeteria and Compound Feeder Pillar (Fig. 5).Figure 5. Schematic diagram for Feeder Pillar No.1By applying the diversity factor, the value of protection and cable sizing shall fit the estimated load. control board.I shows the maximum load that the system can withstand at a t ime. The power at maximum demand is calculated using (2). The power factor is maintained at 0.85. circumvent I. LOAD AT MAXIMUM DEMAND rousePower (kW)MCCB Rating (A)Bengkel Seni61.098100Futsal Court38.49263Cafeteria61.098100Compound Feeder Pillar48.87880(Estimated value of load at maximum demand in Feeder Pillar No. 1)From the existing load as tabulated above, the calculated nominal current is 341.363A using (2). Therefore the rated current of MCCB for the incoming is viable where the rated current of MCCB is 600A.The cables are connected to the busbar. Types of cables used is 4 core, 0.6/1kV, fuzz Cable with earth termination. The cables are terminated to the busbar as pictured in Fig.6.CUsersuserDesktopINTECN8 Afdhalconnection 2.jpgFigure 6. Cables connection to the busbar.From the above figure, it can be observed that the cables connection quite messy where it is hard to indicate which cable is connected to their respected load. It is not labelled to identify the cable. If fault occurrence, it will took a time for the technician to perform maintenance due to the congested condition of the cable.The cable size for each line can be seen from TABLE II.TABLE II . CABLE SIZINGTypeMCCB (A)Cable size of it (mm2)2 x 4C XLPE6001851 x 4C XLPE100501 x 4C XLPE100501 x 4C XLPE80351 x 4C XLPE6325EarthingEarthing is deliberately used to protect human from electric shock due to current leakage. Therefore this feeder pillar has the same earthing mechanism for safety reason.CUsersuserDesktopINTEC1-3-2011 Firdaus N701032011023.jpgFigure 7. Earthing of Feeder Pillar No.1From the fig. 7, all cables are terminated at the same point where it can provide easy path with a low resistance to earth and protect consumer from electric shock. However, those earth cables is not insulated which could lead to current leakage throughout the feeder pillar compartment in case the cable touch the wall of feeder pillar where it is made of steel (good conductor). Therefore, if such case happen ed it will safari electric shock to human who touch the feeder pillar.PROPOSED SYSTEM radial-ply tire Distribution System ImprovementBy referring back to the type of distribution feeder system approached at INTEC, radial type of distribution feeder is applied. Even though radial circuits are simpler to operate and maintain, in vow to increase the reliability and power quality of distribution feeders, networked configurations essential be used 458. However the installation cost of network system will be major obstacle where it required native modification of system. Therefore, elemental loop radial distribution system can be applied to make the system more reliable.Figure 8. Primary loop distribution systemFigure 9. Proposed MCBFig. 8 and 9 illustrate on how the system will look a analogous when improvement can be applied. The base loop consists of two feeders which serve one or several loads. If one feeder fails, the normally open switch can be mechanically (or manually) close d to feed the loads from the backup feeder, once the bad section has been sectionalized. This approach is very useful especially for subsurface cable system since the maintenance of underground cables is complex change that would create long interruptions if chastening occurs.Feeder Pillar Proposed DesignFrom the Feeder Pillar No.1, suggestion can be offered to improve the system is upgrading the feeder pillar to MSB. By referring back to fig. 5, there were two loads that have circuit breaker rating of 100A TPN MCCB while in the MSB as in fig. 3 there were spare load that can be used. Therefore those two loads from Cafeteria and Bengkel Seni can be directly connected to MSB. By this action, the congested condition of feeder pillar can be solved.Figure 10. rising of feeder pillar to MSBSome benefits can be obtained if the load of Bengkel Seni and Cafeteria is transferred to MSBIf fault occur at Feeder Pillar No. 1, those loads will not being interrupted. Therefore it promises the persistency of power supply to the load.The voltage drop of each cable is shown in TABLE III.TABLE III. CABLE VOLTAGE DROPSize (mm2)mV/A/m length (m)IbVoltage Drop (V)1850.22100278.2416.12500.861081.840.708081.845.63351.151065.470.753251.6015049.1011.784(Voltage drop of respected cable in the Feeder Pillar No.1)From TABLE III, it shows that the incoming cables itself obtrude upon high voltage drop which is 6.12V for each cable. Then, if load of Bengkel Seni and Cafeteria is upgraded to MSB, the voltage drop can be observed from TABLE IV.TABLE IV. LOAD VOLTAGE DROPLoadCalculated Voltage Drop (V)Future Length (m)Future Voltage Drop (V)Percentage (%)Bengkel Seni11.7518012.673.05Cafeteria6.821107.7421.87(Future voltage drop if load of Bengkel Seni and Cafeteria is upgraded into MSB)Although the voltage drop risen up since the length of occupied cable is increased, the voltage can be reduce by replacing higher cross sectional area of the cable. However, the value of voltage drop is s till within the specified value of allowed voltage drop 8.By connecting those loads to MSB, the existed feeder pillar will not be congested anymore. Those two loads that were directly connected to MSB will became spare and it can be used for future expansion of nighest building located near to the respected feeder pillar (refer fig. 11).Figure 11. Empty slot of loads acted as spareTherefore the future load will be based on TABLE V.LoadPower (kW)MCCB Rating (A)Futsal Court38.49263Compound Feeder Pillar48.87880SpareSpareThe total load at Feeder Pillar No.1 will be about only 70kW where the nominal current value from the incoming will be only 114.57V that could lead to only 2.52V of voltage drop.EarthingFor earthing cable, it is wise to insulate those cables with PVC insulator to avoid any electric shock due to current leakage. It must meet the electrical standard where earth cable must be insulated with green or green/yellow insulation based on fig. 12 6.http//www.china-wire-cable.co m/photo/6654ca80a2286ebde6efb52e3ffbab88/Earth-Cable.jpgFigure 12. Proper insulation of earth cableComments and SuggestionThe project will become a wise step to ensure that the respected Feeder Pillar No. 1 will become a reliable where it can provide a continuity of supply to a certain loads. However this project could not be implemented immediately since it will took period of time where maintenance underground cables is a complex task where it require skills and occupy more human power. In addition, the substation (PE No.1) need to be shutdown to perform the upgrade process where ironically the substation itself must distribute power to important places such as administration office where it operates 24 hours a day and 7 days per week.Therefore it is recommended that this project must be implemented during the holiday where the total shutdown of PE No.1 can be done and the task of upgrade of the system can be performed by the respected party.CONCLUSIONFrom the case study that was carried out, it is necessary for Facility Unit of INTEC to consider those suggestions in order to overcome any problems related to low voltage power distribution system. afterlife STUDYSurge protection was integrated within the low voltage distribution system to protect the system from lightning strikes. For future study, the recommendation that can be offered to further the respected case study is to perform look on surge protection system in low voltage power distribution system in INTEC.ACKNOWLEDGEMENTThe author would like to express appreciation to his supervisor Ir. Harizan Che Mat Haris due to wise advocate and advices. For INTEC Facility Unit, the author felt pleasured to carry out this case study where he can affix his knowledge and gather more experience. Finally the author wants to offer his gratitude to people who was contributed toward the completion of this case study.