Buchholz relay is a special type of relay which is designed to detect the internal faults by monitoring the gas and oil movement in oil-immersed transformers. This relay is named after Max Buchholz in 1921. This relay is used in the transformer having the rating higher than 500KVA. Due to economic consideration, this relay is … Read more
The distribution of current over the entire cross-section of the conductor is uniform in case of a DC system. But there is an unequal distribution of current over the entire cross-section of the conductor in case of AC system. Here what Skin Effect arises. What is Skin Effect (SE)? When an AC Current flows through a conductor, … Read more
In this article, we will learn Proximity effect that occur in conductors. What is Proximity Effect? Suppose two or more conductors carrying AC current are placed near each other. Each conductor is producing its varying magnetic field. When this varying magnetic field is linked with other current carrying conductors then the distribution of current in each … Read more
Pumped Storage Plant These are a special type of power plant which works as ordinary hydropower plants for part of the time and when such plants are not producing power, they can be used as pumping stations which pump water from tail race to the head race. During this time, these plants utilize power available … Read more
The comparison of steam power plant with hydroelectric power plant is given in the following table. Points Steam Power plant Hydroelectric Power plant 1. Initial cost per kW in ₹ Initial cost is lower than those of hydroelectric & nuclear power plant (1000 to 1500). Initial cost is very high because of dam construction & excavation … Read more
EHV AC stands for Extra High Voltage Alternating current and HVDC stands for High Voltage Direct current. As compared to EHV AC, HVDC has following advantages and disadvantages. Advantages 1. HVDC systems are economical for long distance bulk power transmission by overhead line (reduced tower costs). 2. There is greater power per conductor and simpler line … Read more
Q. Why the thermal efficiency of a steam power plant is quite low? Ans. In a steam power station, more than 50% of the total heat of combustion is lost as heat rejected to the condenser and this loss is unavoidable as heat energy cannot be converted into mechanical energy without a drop in temperature, … Read more
Fuse was patented by Thomas Edison in 1890. Fuse is the simplest & cheapest device used for interrupting an electrical circuit under short circuit or excessive. The fuse element is generally made of materials having low melting point, high conductivity and least deterioration due to oxidation e.g., silver, copper etc. Definition of fuse It is … Read more
When an alternating potential difference between the two conductors of a transmission line is raised beyond a certain limit, a point is reached when a pale violet glow appears on the conductor surface, together with a hissing noise. This phenomenon is known as Corona. Actually, air particles around the conductor surface get ionised and as … Read more
Frequency and Voltage are two important parameters which decide the healthiness of the electrical grid at a particular instant of time. Frequency fluctuations occur in the electrical grid when there is a mismatch between the amount of power generation and amount of power demand. Both under frequency and over frequency operation is harmful to the … Read more