Basic Technology JS2: Transmission of Electricity at low frequency - xpino SCHOLARS

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Thursday, January 8, 2015

Basic Technology JS2: Transmission of Electricity at low frequency






Transmission of Electricity at low frequency

Electrical transmission is the bulk transfer of electrical energy from generating power plants to electrical substations located near demand centers. (Source: Wikipedia)
The position or destination at which the power is received is also referred to as ‘the receiving end.’ The equipment required for transmission are called transmission equipment.
The two types of transmission are:
1.      Primary transmission: this is transmission of power from the generating power station to the main sub-station.
2.      Secondary transmission: this is the transmission of power from the main sub-station to either the domestic consumer or the industrial consumer.

Some transmission equipment are:
1.      Generators;
2.      synchronizing/control panel;
3.      circuit breakers;
4.      sub stations;
5.      transformers (step up and step down);
6.      line support (e.g. tower, pole, insulator cross arms or line separators, etc.)
7.      insulators and lighting arrestor;
8.      power lines;
9.      up risers
10.  feeder pillar;
11.  Bus-bar chamber and fuse board, etc.


Functions of transmission equipment:

1.      Generator control panel: the high voltage (usually 11kv or 33kv) that is generated by many generators are connected to a common 3-phase panel for the purpose of synchronizing the outputs to obtain common frequency and voltage at common bus-bar from which connections are made to a transformer.
2        Circuit breaker: this is a specially designed switch for making or breaking the normal circuit in an electrical system when faulty condition arises. It is essential for ‘shut down’ and maintenance or repair.
2.      Substation: this is an assemblage of equipment for the conversion, transformation, and control of electric power. It is a place outside the power station where electricity is handled.
3.      Transformers: this is used to convert voltages from one value to another, either upward or downward.  The energy being produced at the power station needs to be increased to about 66KV and 33KV by step up transformers so as to prevent power loss during transmission.  However, the consumers need just 220volts or 110volts. Therefore a step down transformer is needed at the consumers’ end of the transmission.

Description of the two types of transformers:
a.     A step up transformer is a transformer whose secondary voltage is more than its primary voltage. It converts low voltage, high current power into high voltage, low current power.





b.     A step down transformer is one whose secondary voltage is less than its primary voltage. It is designed to produce the voltage from the primary winding to the secondary winding. It converts high voltage, low current power into low voltage, high current power.




 
4.      Line Support and Separators: these are the fittings and connectors or supports used in order to avoid the danger of transmission lines touching each other or hanging so low as to cause obstruction to people, trees, vehicles, etc.


Exercises:
1.      What is electrical transmission?
2.      Differentiate between primary and secondary power transmission.
3.      What other name can we call the position or destination at which the power is received?
4.      List the names of five transmission equipment.
5.      Describe the function of four different transmission equipment.
6.      What is a step up transformer?
7.      What is a step down transformer?

Research:
1.      What is an electron?
2.      What is a capacitor?
3.      What is a conductor?
4.      What is an atom?

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