UK National GridDistribution SystemTask 8a. Summarise the reasons for a three-phase supplynetwork A three-phase network is a commonlyused method to alternate current electric power into generation, transmissionand distribution.
Worldwide Power Grids use the system to transfer power. Themain reasons the three-phase network was put in place is due to the fact that ithas a longer life span than that of a one-phase network. A three-phase networkwill produce 3x the power of that of a single-phase network. Also with thethree-phase you get 3 wires instead of the usual 2 wires. Another reason three-phasenetworks are used is the fact they can withstand more pressure and force. Forexample, if a turbine has a single one-phase generator the probability of itbeing shaken to the point of disconnection due to the vibrations and torquevarieties is quite high.
However, a single three-phase generator could handlethis without any stress or problems.Constant power is one of the three-phase network’s keyfeatures. The power is constantly delivered all while the amount of conductor materialis less than a one-phase network. If a test was conducted for both a one-phaseand three-phase network, both networks running the same amount of power andvoltage.
The results would show the three-phase come out on top of the two. Inthe long run the three-phase network is the best option as it is more economicalthan a 2 wire one-phase network. b. Use diagrams to show the voltages at allsignificant parts of the system, from generation through to end user, andbriefly explain the reason for the voltages used Consumers get electricity throughpower stations. Wires and cables within the National Grid are used to transferelectricity from power stations.
Energy is lost as heat when electricity is transferredthrough wires and cables. The National Grid try to/must keep a low flowingcurrent to avoid losing more heat. The more heat is lost, the higher thecurrent gets. A high voltage isneeded to be able to transfer such a low current through cables and wires andto keep the amount of energy from escaping as heat to a minimum. For example, “Powerstations produce electricity at 25,000V. Electricity is sent through theNational Grid cables at 400,000V, 275,000V and 132,000V.” (Bbc.co.
uk,2018) Power stations use step-uptransformers as they can create the extremely high voltages that are needed totransmit electricity through power lines. Another transformer is used todramatically reduce the voltage before it enters an average household. This isdone through a step-down transformer, which is the last process before a safe voltageof 230V is distributed into each household. BBC – GCSE BITESIZE: THE NATIONAL GRIDIn-text: (Bbc.
co.uk, 2018)Your Bibliography: Bbc.co.uk. (2018).
BBC – GCSEBitesize: The National Grid. online Available at:http://www.bbc.
co.uk/schools/gcsebitesize/science/aqa_pre_2011/energy/using_electricityrev1.shtmlAccessed 19 Jan. 2018.Please enable flash to have the best experience Check for grammar