Buchholz Relay – Construction and Working Principle

Buchholz relay is a gas actuated protection relay which is generally used in large oil immersed transformers of rating more than 500 kVA. It is used for the protection of a Transformer from the faults occurring inside the transformer. A typical Buchhloz Relay is shown below.   The gas actuated protective relay is designed to … Read more Buchholz Relay – Construction and Working Principle

Transformer Testing

For the purpose of quality assurance and ensuring that the finished transformer conforms to customer requirements and is ready for service a barrage of tests are performed on the transformer. These can be broadly classified into the following 3 types: Routine Test, Type Test and Special Test. 1) Routine Tests: These are standard tests performed … Read more Transformer Testing

Difference between Brushed and Brushless Motor

Brushes are used in two main types of motors: DC motors and large synchronous motors, called wound-rotor synchronous motors. There is a third case in which brushes was used, the wound-rotor induction motor that has been obsolete for many years. In the DC motor case, the brushes transfer current into the rotor via the commutator. … Read more Difference between Brushed and Brushless Motor

Reactive Power and Voltage Control of a Transmission Line

For understanding the relationship between the Reactive Power flow in a Transmission Line and Voltage drop, we will consider Short Transmission Line for simplicity. A short transmission line is one whose length is less than 80 km. For short Transmission Line Resistance and Reactance of line is assumed lumped. The important thing for short Transmission … Read more Reactive Power and Voltage Control of a Transmission Line

Significance of Burden in Potential Transformer

Before going into the impact of Burden on the performance of a Potential transformer, we will discuss about Burden. The Burden of an Instrument Transformer is the rated Volt-Ampere loading which is permissible without errors exceeding the limits for a particular class of Instrument Transformer. Basically, there are two Classes of an Instrument Transformer, one … Read more Significance of Burden in Potential Transformer

Single Phase Induction Type Energy Meters

As we know that the total energy consumed by a load is given as, E = P.t where P = Power and t = time But as the load current may not be constant rather it will vary as per the loading therefore we need to use integration for calculating the total energy consumed by … Read more Single Phase Induction Type Energy Meters

Power Line Carrier Communication (PLCC)

Power Line Carrier Communication, often called PLCC, is used for speech data transmission as well as protection of Transmission Lines. Carrier current used for Power Line carrier Communication has a frequency range of 80 to 500 kHz. PLCC is mainly for telemetry and telecontrol in modern electrical Power System.     Power Line Carrier Communication … Read more Power Line Carrier Communication (PLCC)

Different types of Energy Meters

There are basically three types of energy meters: Electromechanical Energy Meter: The electromechanical induction meter operates by counting the revolutions of a non-magnetic, but electrically conductive, metal disc which is made to rotate at a speed proportional to the power passing through the meter. The number of revolutions is thus proportional to the energy usage. … Read more Different types of Energy Meters

How Twisting the Cables Reduce the Interference?

Twisting the cables is done to remove the electromagnetic interference from the wires. When a signal is transmitted through the cable it is in the form of current. This flow of current produces an electromagnetic field of interference around it and can generate noise effects in the surrounding cables. One pair can induce cross-talk in … Read more How Twisting the Cables Reduce the Interference?