Tricky but Easy Electrical Engineering!
We are quite familiar with Synchronous Generator or often called Alternator. There are mainly two types of Synchronous Generator from rotor construction point of view. The two main types of synchronous machine are Cylindrical Rotor and Salient Pole. Saliency simply means projection outward. Therefore from the literal meaning of Saliency one can guess that Salient … Read more
Transformer Physical Protection refers to the Protections which used the physical quantities to protect the Transformer. Apart from electrical protections which uses the electrical quantities to judge a fault and based upon the judgment, the electrical protections of Transformer isolates the Transformer. On contrary, physical protections continuously measure the physical quantities like oil / winding … Read more
In this post I will focus on the working principle of the Bipolar Junction Transistor assuming that you are already aware of the construction details of the BJT or simply Transistors. The basic operation of the transistor will be described using the pnp transistor. The operation of the npn transistor is exactly the same if … Read more
The clamping network is one that clamps a signal to a different DC level. The network contains a capacitor, a diode, and a resistive element, but it can also have an independent DC supply source to introduce an additional shift in voltage level. The magnitude of R and C to be used in the Clamper … Read more
Programmable Scheme Logic or PSL is a kind of feature provided in Numerical Relays to implement the protection scheme of a particular type. This feature of Numerical Relays makes it easier to implement many protection schemes in a single Numerical Relay for example, in Distance Relay we can configure Distance protection, over voltage protection, Over … Read more
In this post we will discuss, why electric field inside a conductor is zero. This is very basic but important concept to understand. So we will start will zero and will move further to explain this. Let us assume that a conductor is kept in an external uniform electric field E. The direction of electric … Read more
I would suggest to read Transformer Inrush Current before reading this article for better understanding. Any event on the power system that causes a significant increase in the magnetizing voltage of the transformer core results in magnetizing inrush current flowing into the transformer. The three most common events are as follows: Energization of the Transformer. … Read more
This test is necessary for all indoor and outdoor breakers. The test is carried out as follows: Standard impulse wave of specified amplitude is applied five times in succession. If flash-over or puncture of insulators does not occur, the circuit-breaker is considered to have passed the test. If puncture occurs or if on two or … Read more
Endurance Test of Circuit Breaker is conducted to check the healthiness of its mechanical parts i.e. operating mechanism. In this test, Circuit Breaker is operated several times and checked for any damage of its mechanical parts / contacts. The breaker should be in a position to open and close satisfactorily. This test is also called … Read more
Rated Normal Current: The rated normal current of a circuit-breaker is the r.m.s. value of the current which the circuit breaker can carry continuously and with temperature rise of the various parts within specified limits. The design of contacts and other current carrying parts in the interrupter of the circuit breaker are generally based on … Read more