LESSON 1

 UNDERSTANDING HOW POWER IS DISTRIBUTED

Distribution is done with the aid transmission and distribution networks which transmit electrical power at various voltages. Such distribution networks can be either overhead or underground. Power Holding Company of Nigeria (PHCN) is the agency of the government responsible for generation, transmission and distribution of electricity in Nigeria This Center controls every other transmission and power station linked to the grid in the country In Nigeria, after electrical power is generated by a power station at voltage of 16000V (16KV) .  The electrical energy generated is then stepped up by a step up transformer to a voltage level of 330000V (330KV) for transmission. It is more desirable to transmit electrical energy at very high voltage and low current level because doing this minimizes losses in transmission. The transfer of electrical energy at such a high voltage level is usually referred to as transmission. This voltage level is reduced at sub-transmission stations to 132000V (132KV) for sub-transmission. It is further stepped down to 33000V (33KV) at sub stations. Large industries and some customers are fed at this voltage level. The electrical energy is further stepped down to a voltage level of 11000V (11KV) for supply to distribution sub-stations. General consumers are fed from distribution sub-stations at a voltage level of 415/230V.