When the current carrying contacts of the circuit breaker are moved apart, an arc is formed, which insist for a short period after the separation of contacts. This arc is dangerous on account of the energy generated in it in the form of heat which may result in explosive force. The circuit breaker should be …
A circuit breaker in which SF6 under pressure gas is used to extinguish the arc is called SF6 circuit breaker. SF6 (sulphur hexafluoride) gas has excellent dielectric, arc quenching, chemical and other physical properties which have proved its superiority over other arc quenching mediums such as oil or air. The SF6 circuit breaker is mainly …
Oil circuit breaker is such type of circuit breaker which used oil as a dielectric or insulating medium for arc extinction. In oil circuit breaker the contacts of the breaker are made to separate within an insulating oil. When the fault occurs in the system the contacts of the circuit breaker are open under the …
A circuit breaker is a switching device that interrupts the abnormal or fault current. It is a mechanical device that disturbs the flow of high magnitude (fault) current and in additions performs the function of a switch. The circuit breaker is mainly designed for closing or opening of an electrical circuit, thus protects the electrical …
When a fault occurs, the fault current flow to the ground due to which the potential gradient near the electrical equipment developed. This potential gradient may affect a person in two ways, either by step-to-step contact or by touch contact. Step-Potential – Step potential is the potential difference between the feet of a person standing on …
Booster transformer is one which is often used towards the end of a power line to raise the voltage to the desired value. It is used for controlling the voltage of a feeder at a point far away from the main transformer. The secondary of the booster transformer is connected in series with the line, …
A static VAR compensator is a parallel combination of controlled reactor and fixed shunt capacitor shown in the figure below. The thyristor switch assembly in the SVC controls the reactor. The firing angle of the thyristor controls the voltage across the inductor and thus the current flowing through the inductor. In this way, the reactive …
Thyristor Controlled Reactor Thyristor controlled reactor consist reactor L placed in series with the thyristor valve. This reactor is the controlled element of the TCR, and it controls the thyristor valve. TCR consists two opposite poled thyristor which conducts every alternate half cycles of the supply. In TCR the duration of current flowing through the …
Thyristor Controlled Reactor & Thyristor Switched Capacitor Read More »
The potential gradient in a power system is defined as the rate of change of electric potential with respect to the distance from the base of the electrical structure. The resistance of the earth electrode is not concentrated at one point, but it is distributed over the soil around the electrode. When a fault current …
When the system is unbalanced the voltages, currents and the phase impedances are in general unequal. Such a system can be solved by a symmetrical per phase technique, known as the method of symmetrical components. This method is also called a three-component method. The method of symmetrical components simplified the problems of the unbalanced three-phase …
