EWA Owned Power Plants and Independent Power Producers (IPP) generate electricity by the parallel connected three phase alternators/generators in Kingdom of Bahrain.
The Power Plant generating voltage is 11kV & above but less than 21KV. The same is stepped up to 220KV and 66KV by step up transformer to transmit bulk power to load centers.
Step Up Transformers:
On a step-up transformer there are more turns on the secondary coil than the primary coil. The induced voltage across the secondary coil is greater than the applied voltage across the primary coil or in other words the voltage has been “stepped-up".
Generally the Step-Up transformers are located in Generating stations to step-up the produced low voltage to high voltage for bulk power transmission.
220KV Under Ground Cables:
In Bahrain, EWA network, Extra High Voltage transmission of electricity is achieved through 220KV underground power cables from generating stations to various Bulk Supply Points(220/66KV Substation) and from one Bulk Supply Point to another Bulk Supply Point. The cables buried under ground has given aesthetic look to the Kingdom of Bahrain.
EWA electricity network has numerous 220KV Bulk Supply Points spread all over the Kingdom, where 220/66KV step down power transformers are connected to reduce the voltage levels from 220KV to 66KV for further transmission of electricity.
66KV Under Ground Cables:
In EWA network, electricity transmission from Bulk Supply Points to various loop type and city type substations are connected through 66KV underground cables. The cables being buried under ground has given aesthetic look to the Kingdom of Bahrain.
66/11KV Power Transformers:
The sub-transmission network of the EWA, Bahrain is connected to 66/11KV Substations. The 66/11KV Power Transformers step-down the voltage from 66KV to 11KV to transmit electricity to Distribution network.
Substation is an integral part of a power system and form important links between the generating station, transmission systems, distribution systems and the load points. EWA Bahrain network has numerous 220KV,66KV Gas Insulated Substations. All 66KV Gas Insulated substations are titled as Primary substation.
The OLD sub-transmission network of the EWA, Bahrain is connected to 66/33KV Substations. The 66/33KV Power Transformers step-down the voltage from 66KV to 33KV to transmit electricity to Secondary 33/11KV Substations.
33KV Under Ground Cables:
In EWA network, electricity transmission from Primary Substations (66/33KV) to various 33/11KV Substations is achieved through 33KV underground cables. Few 33/11KV secondary substations are left in Kingdom of Bahrain still feeding the old Manama and Muharraq governorates. These Substations soon be phased out and will be replaced with new 66/11KV Primary Substations.
The OLD sub-transmission network of the EWA, Bahrain is connected to 33/11KV Substations. The 33/11KV Power Transformers step-down the voltage from 33KV to 11KV to transmit electricity to Distribution Substations.
In electricity distribution network there are a lot of secondary substations(11/0.4KV) feeding all EWA customer except high voltage customers.
Transmit the output voltage for the generators before stepping it up the voltage for transmission.
The last stage of transmitting the electricity power to the customers is to reduce the voltage from 11 kV to 400 volt “3 phase" or 220 volt “single Phase".
Pole Mounted Transformers:
Pole mounted transformer is small 11/0.4 kV transformer and there are very few of them used in a place where they need small amount of power and the place is very far from city or villages like the farms.
LV. Over Head Line:
The LV overhead line supplies the customer by electricity, nowadays the number of overhead line is so few.
A type of customer that need small amount of power.
LV Under Ground Cables:
The LV underground cables supplies the customer by electricity, nowadays almost all distribution network that supplies the customers are underground cables.
In EWA there are different customer and we categorize the as per the amount of power consumed and the level of voltage required by them.