All AC circuits are made up of the combination of resistance R, inductance L and capacitance C. The circuit elements R, L, and C are known as circuit parameters. To study a general AC circuit it is necessary to consider the effect of each parameter separately. Purely Resistive Circuit A purely resistive circuit is a […]
In a DC system, the voltage and current are constant, therefore, there is no problem in specifying their magnitude. But in the case of an AC system, an alternating voltage varies from instant to instant and so poses a problem in specifying the magnitude. So to express the AC quantities in an easy and understandable form,
Dielectric heating is also known as radio frequency heating or electronic heating. When a non-metallic material such as wood, plastic, bone, or ceramic is subjected to an alternating electrostatic field, the dielectric loss occurs in it. This loss appears in the form of heat in dielectric heating. It is the basic dielectric heating principle. A
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In the electric arc furnace, the heat is generated by an electric arc. In this furnace, the arc may be created by the following different ways: 1. By striking the arc between the charge and electrode: In this method, the heat is directly conducted and taken by the charge. The furnace operating on this principle
The induction heating works on the transformer principle. It is also known as eddy current heating. In these machines, the currents are induced by the principle of electromagnetic induction. It may be of low frequency as in the case of core type induction furnaces or of high frequency as in the case of coreless induction
The basic principle of resistance heating is that, when current passes through some resistance, power loss takes place which appears in the form of heat. There are two types of resistance heating, namely, direct resistance heating and indirect resistance heating. Direct Resistance Heating In the direct resistance heating, the electric current passes through the charge
The supporting structure for overhead lines is required to keep the bare conductors at a suitable level above the ground. These may be various types of poles or towers. They should have following essential properties: Types of Poles in Transmission Line The following are main types of poles and towers generally used in the overhead
The overhead line conductors are supported on the poles or towers. In order to prevent the flow of current to earth through supports, the line conductors must be properly insulated from supports. This is achieved by securing line conductors to supports with the help of overhead line insulators. These insulators provide necessary insulation between the line
The cost of conductor material is a vital part of the total cost of a transmission line. Therefore, the calculation of the conductor size of a transmission line is very important. The economic size of conductor is determined by Kelvin’s law. It is used to find out the most economical area of x-section of a
The transmission of electric power over long distances was developed at the beginning of the twentieth century. Since then, it has made rapid progress in its design and methods of operation, which has resulted in greater reliability and continuity. The electric power can be transmitted either by means of an AC or DC system. Each