A study on power quality improvement in distribution network using unified power quality conditioner

Abstract

Nowadays, the power system is complex, interconnected and varies in sizes and configurations. A large amount of electrical energy is generated in hydroelectric, thermal, nuclear and gas power stations, also called conventional electric energy sources. Some amount of electricity is generated through non-conventional sources of energy. This power is also called green power as it emits less pollution. Generated electric power is transmitted to the load centers through the power supply network consisting of transmission lines, transformer and switchgear. Transmission networks are commonly classified into four parts: transmission system, sub-transmission system, primary distribution system and secondary distribution system. Energy is often converted into the electrical form which is used in the form of light, heat and mechanical energy. Utilization of power is restricted to low voltage only. Before feeding the power to consumers, the transmission voltages are stepped down and power is transmitted over distribution lines. Distribution systems are further divided into two parts, one is primary and another one is secondary distribution systems. Sub transmission systems form the link between the main receiving station and the secondary substation. At the secondary substations, the voltage is stepped down and power is fed into the primary distribution system, which feeds power to medium and large consumers at the level of distribution voltage higher than 400 V. It is normally 33 kV, 25 kV, 11 kV and 6.6 kV in India. The secondary distribution feeders supply at 400 Volts for residential and commercial customers. Distribution systems have the largest share in power system network. Thus the power quality is one of the important issues in the distribution systems. newline