Found 451 Articles for Electron

Electricity TariffThe electricity tariff is defined as the rate at which the electrical energy is sold to a consumer.However, the tariff should include the total cost of producing and supplying electrical energy plus the profit to the power company. In practice, the tariff cannot be same for all types of consumers because the cost of production of electrical energy depends upon the magnitude of electrical energy consumed by the user and his load conditions. Therefore, the tariff is fixed by considering the different types of consumers such as domestic, industrial and commercial, etc.Objective of TariffLike any other product, the electrical ... Read More

The power factor of the load connected to the power system considerably affects the voltage regulation and efficiency of a transmission line.Effect of Load Power Factor on Voltage RegulationThe expression for percentage voltage regulation of a transmission line, when a load of lagging power factor is connected to the system, is given by, $$\mathrm{\%\:Voltage \:Regulation\:=\:\frac{\mathit{IR}\:cos\:\phi _{\mathit{R}}\:+\:\mathit{IX_{\mathit{L}}}cos\:\phi _{\mathit{R}} }{\mathit{V_{\mathit{R}}}}\:\times \:100\%\:\:\:...\left ( 1 \right )}$$Where, suffix R denotes the receiving end quantities.Also, the percentage voltage regulation for leading power factor is given by, $$\mathrm{\%\:Voltage \:Regulation\:=\:\frac{\mathit{IR}\:cos\:\phi _{\mathit{R}}\:-\:\mathit{IX_{\mathit{L}}}cos\:\phi _{\mathit{R}} }{\mathit{V_{\mathit{R}}}}\:\times \:100\%\:\:\:...\left ( 2 \right )}$$Therefore, from equations (1) and (2), the following points can ... Read More

Variable Load on Power StationThe load on an electric power system changes from time to time due to uncertain demands of the consumers, this variation in load of a power station is termed as variable load on power station.An electric power station is designed to meet the load requirements of the consumers. From the standpoint of equipment needed and operating routine, an ideal load on a power station would be of constant magnitude and of steady duration.However, in actual practice, such a steady load on the power station cannot be realised. It is because the consumers require different blocks of ... Read More

Power FactorThe cosine of angle between voltage and current in an AC circuit is called the power factor of the circuit. In other words, the power factor is defined as the ratio of active power to the apparent power in the circuit, i.e., $$\mathrm{Power\: factor, cos\:\phi\:=\:\frac{Active\: power\: (in \:Watts)}{Apparent\: power\: (in\: VA)}}$$Where, $\phi$ is the power factor angle.Causes of Low Power FactorFrom the economic point of view, the low power factor of the load connected to a power system is undesirable. The main causes of low power factor are given as follows −The AC electric motors consist of inductive winding. ... Read More

The useful output of a power generating station is the kW output which is delivered by the station to the electrical supply system. Sometimes, a power generating station needs to deliver more kW to meet the increased power demand. This can be achieved by any of the following two methods −By increasing kVA capacity – In this method, the kVA capacity of the power generating station is increased at the same power factor to meet the increased kW demand. Although, this causes extra cost to increase the kVA capacity of the power station.By improving power factor – In this method, ... Read More

Most Economical Power FactorThe value to which the power factor should be improved so as to have maximum net annual saving is called the most economical power factor.When a consumer improves the power factor, it results in reduction in his maximum kVA demand. Consequently, there will be an annual saving over the maximum demand charges. Although the power factor improvement involves the capital investment on the power factor correction equipment, the consumer will draw expenditure every year in the shape of annual interest and depreciation on the investment made over equipment used for power factor correction. Hence, the net annual ... Read More

Depreciation of Power Plant EquipmentThe reduction in the value of the equipment and other property of the power station every year is known as depreciation. Therefore, a suitable amount, called depreciation charge, must be set aside annually so that by the time the life span of the power plant is over, the collected amount equals to the cost of the replacement of the power plant.Straight Line Method of DepreciationIn the straight line method of calculating depreciation, a constant depreciation charge is made every year on the basis of total depreciation and the useful life of the equipment or other property. ... Read More

The cost of conductor material required for designing a transmission line is a very considerable part of the total cost of a transmission line. Therefore, the determination of proper size of the conductor for the transmission line is very important. The proper size of the conductor for transmission line is determined by the Kelvin’s law (given by Lord Kelvin in 1881).The Kelvin’s law states that the most economical area of conductor is that for which the total annual cost of transmission line is minimum.The total annual cost of the transmission line can be divided into two parts viz. −Annual charges ... Read More

Depreciation of Power Plant EquipmentThe reduction in the value of the equipment and other property of the power station every year is known as depreciation. Therefore, a suitable amount, called depreciation charge, must be set aside annually so that by the time the life span of the power plant is over, the collected amount equals to the cost of the replacement of the power plant.Diminishing Value Method of DepreciationIn the diminishing value method for calculating the depreciation, the depreciation charge is made every year at a fixed rate on the diminished value of the equipment, i.e. the depreciation charge is ... Read More

Overhead DC Transmission SystemThe overhead transmission system is the one in which the conductors are hanged with the help of pole supports. When the transmission lines carry direct current, then the system is called the DC transmission system.There are three types of overhead DC transmission systems viz. −Two wire DC system with one conductor earthedTwo wire DC system with mid-point earthedThree wire DC systemConductor Material Required in Two-Wire DC System with One Conductor EarthedConsider a two wire DC system with one conductor earthed as shown in Figure-1. Here, one is the positive wire and the other is the negative wire ... Read More