1.0ELETRICALSUPPLY SYSTEM1.1Literature Review1.
1.1PowerTransmission System Kota Bharu Medical Centre,also known as KBMC, is locateded in Jalan Sultan Yahya Petra, Taman Aman, 15200Kota Bharu, Kelantan. It is the first Private Specialist Hospital in Kelantan.It provides in-house specialists services for patients with medical conditions andalso out-patient for mild discomfort. Therefore, the building itself aredepending on the electricity the hospital instruments cannot function withoutelectricity.
Electricity is very important to a hospital. Without electricity,hospital cannot function and it may miss the chance to help a patient.Electricity in the building mostly for lighting, air conditioning, elevators,fire system and hospital instruments.
Various power station produced highcurrent electricity such as Tenaga NationalBerhad. The conveyance of electrical power from a station to consumers’premises is known as electrical supply system. An electrical supply systemconsists of three principal components which is the power station (generationsystem), the transmission lines and the distribution system.Figure1.1: Basic Structure of the Electrical System for theGenerating System, Transmission Lines and Distribution System.(Source: http://www2.econ.
iastate.edu/classes/econ458/tesfatsion/Home458Team.htm) Electricity generation is the firstprocess in the delivery of electricity to consumers. The electricity isgenerated at a power station by electromechanical engines fuels by chemicalcombustion and also other kinetic energy such as flowing water. These are thetwo types of energy which we can see in Malaysia. Other energy source includegeothermal power.
One of the generation system is water turbine. The way ofwater turning to electrical energy is the flowing water will directed on theblades of a turbine runner, creating a force on the blades and pushing it to spin. When the turbine is spinning, the forceacts through a distance (force acting through a distance is the definition ofwork). This is the way that turn water to energy with the turbine.
Theelectrical energy transfer by the transmission line or Electric-powerTransmission system from the generating power plants to the substations ofelectricity to the located near demand centers. This is different from thelocal wiring between high-voltage substations and customers, which is typicallyreferred to as electric power distribution. Transmission lines, wheninterconnected with each other, become transmission networks. The combinedtransmission and distribution network is known as the “power grid”.
Most of thelines are suing high-voltage three-phase alternating current (AC). High-voltagedirect-current (HVDC) technology is used for greater efficiency in very longdistances (hundreds of kilometres) or in submarine power cables (longer than 50km). Electricity distribution is the last stage in the delivery of electricity.A distribution system’s network carries electricity form the transmissionsystem to the customers.
Normally, the network include medium-voltage(2kv-34.5kv) power lines, substations ad pole-mounted transformers,low-voltage(less than 1kv) distribution wiring and sometimes meters. 1.1.2Electrical ComponentsElectrical supply system is divided into two types, the off-site powersystem and the on- site power system.
The on-site power system contains normalpower sources such as transformers, auxiliary power supply, cables andemergency power supply (generator). The power consists of the grid, generators,and transmission and distribution systems. Power used on-site can be generatedon-site, rather than imported from distribution grids, often morecost-effectively and with the added advantages of avoiding distribution lossesand offering a measure of energy independence. On-site generation can providean essential redundancy to power provided by the local electric utility. Almostall of the current operators of cogeneration plants can get their power fromthe local electric utility if needed. This provides a dual source of energy, asthey have power available when their systems are down (say for occasionalmaintenance) or when there is a failure of the local electric utility.
Thisredundancy in turn can provide for health and safety, industrial processcontinuity or significant protection from computer and information technologyupset, resulting in significant cost savings. Electricalsupply from TNB is firstly distributed to the high voltage (HV) room of abuilding. Lower voltage (LV) room then receives electrical supply from HV roomand transmits electricity to riser on each floor of a building.
The risers thendistribute electrical supply throughout the floors. Generator rooms can only befound in private buildings which acts as an emergency power system. Newlydeveloped buildings adapts the Building Automatic System (BAS).
It monitors andcontrols facilities through a centralized system, such as lighting, air handingunits, switchboards and CCTV.
