Proximity Effect is a phenomenon which is observed in conductors carrying alternating current. When a conductor carries ac power, the constantly varying magnetic field induces eddy currents in the nearby conductors. In conductors where the current flows in the same direction, this results in increased current density in the nearby conductors due to the changes in the current distribution across the cross-section of the conductor. Thus the resistance of the conductor increases.In the pictur... Read Full Story

Noise and Vibration in Transformers are undesirable aspects of Transformer Operation. Noise causes disturbance in localities where the transformer is located. Vibration in transformers can affect other components connected to it. Sometimes, excessive vibration can cause components inside the transformer to come loose.Methods of Noise Attenuation:Location of a transformer plays a crucial part in the level of noise. A transformer located in a corner of a building with walls on three sides w... Read Full Story

Transformer Noise is caused by a phenomenon called magnetostriction which occurs inside the transformers. Magnetostriction is a phenomenon by which a metallic objects experiences a distortion in its shape when it is placed inside a magnetic field. The objects can experience a change in the dimensions, expansion or contraction.Inside a transformer, the core which is made in the form of laminated sheets also undergoes expansion and contraction due to the changing magnetic flux. This expansio... Read Full Story

Substations are installations in a Transmission and Distribution System which are involved in the connection of different sections of the transmission and distribution system, usually with the transfer of electrical power from one voltage level to another. Substations play a vital role in integrating the generating, transmitting and distributing parts of an electrical system.A substation is generally located in an open area. The substation contains of numerous equipments such as transfo... Read Full Story

Ampacity or 'ampere-carrying capacity' refers to the ability of a conductor such as wires, cables or busbars to carry current without getting damaged due to overheating.The ampacity of a conductor should be optimimum with respect to the application. A lower ampacity would result in heating and damage to the insulation. An excessive ampacity selection would result in unnecessarily high costs. The ampacity of any conductor depends on the following factors.The temperature rating of its insula... Read Full Story

Lightning arrestors play a vital role in any substation by protecting equipment against lightning strikes and other surges. Lightning arrestors require very less maintenance and testing.Lightning arrestors can deteriorate over a period of time due to factors such as dust, cracks, moisture ingress, degradation of the zinc oxide elements inside, etc. This can lead to failure of the lightning arrestor. When a lightning arrestor fails, it usually explodes causing a flashover and damage to the o... Read Full Story

Surge capacitors are special capacitors connected to transmission lines. The function of these capacitors is to absorb the surge caused by waves which travel along the transmission lines. The Surge Capacitor is always connected to the power supply. When the Surge appears it absorbs the surge, holds it on for sometimes and then releases it into the system.Surge Capacitors have a very fast response time as they are continually in circuit.However, the limitation of the Surge capacitors is tha... Read Full Story

Capacitors are devices which store charge as an electrostatic field. When the supply connected to a capacitor is removed, the capacitor still retains the charge within itself.Thus, when a capacitor is switched off, it still contains charge. Hence, an engineer working on a capacitor that has not been discharged can get an electric shock. It is, therefore, vital that all capacitors and other energy storage devices be discharged prior to service. Power capacitors usually have a resistor know... Read Full Story

Bulging in capacitors is caused due to pressure inside the capacitor body. This pressure can be caused due to arcing between the capacitor plates and the resultant generation of gases. Such capacitors need to be handled carefully. Always contact the capacitor manufacturers on handling or disposing the capacitor units.Vents are provided in some capacitors as a defence against bulging. Vents need to be periodically checked for rupture which may indicate failure. Read Full Story

Dry - Type:These transformers use air as the cooling medium. These transformers are generally used for indoor applications. This kind of cooling can be applied for transformers up to 20 MVA.These Transformers can be further classified intoa)Natural Cooled:These transformers can be Natural Cooled with Air (Air - Natural). The natural convection of the air removes the heat generated by the transformers. The symbol for this type of cooling is AA. b)Forced Air Cooling:This involves cooling th... Read Full Story