Step Potential and Touch Potentials are very important in substations because during ground faults all the ground current returns to the substation transformer (as the substation transformer is grounded). The current that returns through the earth can create a significant voltage gradient along the ground and between ground and conducting objects. A step potential in … Read more
Majority of electrical substations will be the air insulated type. All the electrical equipment live parts will be exposed. All the electrical equipment in the substation shall be arranged in such a manner to ensure the clearance space between the live parts and other equipment of the substation (grounded or ungrounded). Adequate clearances should be … Read more
Creepage Distance for Insulators The creepage distance for insulators is the shortest distance along the insulator surface between the metal parts at each end of the insulator. Creepage distance can also be referred as leakage distance for insulators. Insulators in substation are provided to avoid any leakage current from live electrical conductors to flow to … Read more
With an increase in the operating voltage, the insulation requirement will also increase. Transmission system will have transmission voltages as high as 400kV and above voltage levels. At these voltages, the pin insulators become bulky, cumbersome and costly. You can read about Overhead Line Insulators here. Some of the advantages of suspension insulators over pin … Read more
Normal loads on an AC supply system are inductive in nature (eg: motors, power transformers, voltage regulators, induction furnace, choke coils, magnetic systems, discharge tubes etc) Inductive power requires reactive power in addition to active power (active power is required to do the true work). The reactive power increases the load imposed on the system. … Read more
Any two conductors separated by an insulating medium constitutes a condenser or capacitor.In case of overhead transmission lines, two conductors form the two plates of the capacitor and the air between the conductors behaves as a dielectric medium. Thus an overhead transmission line can be assumed to have capacitance between the conductors throughout the length … Read more
Generally, in the secondary distribution system, single phase two wire distribution system is generally followed. But for remote distribution systems in rural areas single-phase ground return system has found economical. In this system, the earth is used as return conductor and only one phase wire or conductor is used. This system requires grounding rods deep … Read more
All the equipment connected to the power utility system is designed to be used within the voltage range. Voltage drop exists in each part of the system. Consumers who are electrically connected to the primary distribution feeder near to the substation will have maximum voltage levels compared to consumers who are located at the tail … Read more
The factors to be considered for evaluating the suitability of a cable for a particular application are load, system voltage, cable insulation, short circuit rating, environmental conditions, sheath and protective coverings, heat dissipation losses, economic considerations etc. The following points are important Maximum continuous current rating System Earthing Voltage drop Conditions of installation Expected Short … Read more
In power distribution system both aluminium and ACSR are commonly used. Mostly aluminium conductors are used in the distribution system because of cheaper in cost. Some of the factors which decide the size of the conductors designed for distribution system are given below: Current carrying capacity of the conductor or distribution line Allowable voltage drop … Read more
