A valve type lightning arrester is an improved and expensive lightning arrester which is also called a nonlinear surge diverter. A valve type arrester gets its name from the fact that a nonlinear resistor regulates itself from th…
What is Surge Absorber or Lightning Absorber? A surge absorber is a protective device that absorbs the high voltage surges and reduces the steepness of the surge wavefronts. The traveling waves set up by the surges on the transm…
Power transmission lines and associated equipment in the substations are subjected to overvoltage which is generally due to lightning discharge or internal causes (switching operation, sudden changes in load, insulation failure, …
The lightning arrester or surge arrester is the surge protection device used to limit the overvoltages in substations to a specified protection level. These devices are used to protect the conventional as well as gas-insulated su…
Power transmission lines and associated equipment in the substations are subjected to overvoltages or surge voltage, which are generally due to lightning strikes. A lightning strike is an electrical discharge in the form of a hug…
The relays whose operation is governed by the ratio of the applied voltage to current in the protected circuit is known as impedance relay. It is a distance relay that measures the distance by equating the fault current with volt…
It can be seen that there is a rapid increase in the expansion of transmission and distribution systems and power stations day by day. This results in the increase of duty imposed on the switchgear equipment. Since the relays no…
When there is a sudden and large change in the power system i.e., due to removal of a fault or a sudden change in the load, there will be a change in the phase angle between the induced voltage on the line. Consider a transmissi…
The increase in the transmission line lengths and the amount of power transmitted through the lines will result in rise of new problems in relation to the protection. This also leads to the rise of new techniques in order to hand…
The induction relay works on the principle of electromagnetic induction similar to the induction motor and energy meter. It consists of two electromagnets and a rotating disc placed between the two electromagnets. The torque prod…
The overcurrent relays are used for the protection of electrical equipment against fault currents. But this type of relay is not very sensitive as they cannot distinguish between overloads and minor fault conditions. This can be …
