E-Throttle

  Lightning.....! the wicked thing in our power system.                     For us it creates only damages. So is important to protect the crores worth devices which support the generation, transmission and distribution of power. Starting from the generating stations, all the power cables are connected to a device which is called surge diverter or lightning arrester. In transmission towers we draw a separate line for earth at the top of the tower. By that line we create a zero potential at the top of tower. Thus protecting transmission lines from lightning surges. Electrical surge produces a large transient over voltage in the electrical network and system. The shape of the transient over voltage has a steeply rising front with slowly decaying tail. There are two types of surges one comes externally from atmosphere such as atmospheric lightning. Second type is originated from electrical system itself, such as swi...

What do we do if a circuit breaker or any other power flow controlling device gets faulty and we want to gain control over a device(say a bus or line or transformer,etc) ,Yes there have to be some sort of back up for it ,a master manual switch, which could be used for isolation of one network part from another, called Isolator. It enhances the safety of the maintaining part in the power system by complete de-energizing it. Well ,lets lean on it. Just visualize a switch having capability of circuit disruption, handling of load current, mechanical properties needed for its operation and more importantly as we are dealing with high voltage there has to be a provision for its separation from metal parts in which it is fixed about, for this usually the solution is solid porcelain core type insulators,having high mechanical strength and dielectric strength. Operation                              The...

  Did we want to really concerned about the current transformers ? Its just an instrument transformer Yeah!,  that's make it different in protective relaying Lets dig deep                             In the most protective relays the input quantity is current and these current are supplied by current transformers. located on or near to the protected equipment. The main functions of CT are 1. To isolate the power system circuit from protection circuit 2.Reduction of magnitude to a level accessed by relays and meters  When considering Constructional features, these are similar to normal transformers consisting a magnetically coupled primary and secondary windings, wound on a common iron core and the primary is connected in series with  the network and the ratio could be found from basics ie,   Ampere-turns in primary=Ampere-turns in secondary ie, low no. of t...

It is very important to manage and measure the Extra High Voltage level which we use to transfer power from one point to other. Since the insulation gradient for Extra High Voltage(EHV) is very high, it is difficult to measure this high voltage. So for the measurement its necessary to reduce the voltage level.  Here we generate a reference voltage with respect to the EHV using a Voltage Transformer(VT) or Potential Transformer(PT).  So we refer potential transformer as step-down transformers. Such types of transformers come under the classification of Instrument transformer. Potential Transformers are same as that of a power transformer, but they are used for the protection and measurement of the system voltage. Since its duty is just to measure the magnitude of voltage, its always connected in parallel to the Power lines supplying loads. We usually here the word Potential Transformers while working in a medium voltage switchgear room and substations, power s...

Power factor ! We might have heard the word power factor earlier! Yes it can be simply define as the ratio of real power(KW) to the apparent power(KVA) Denotes as "cosφ" where  phi is the phase angle between voltage and current.          Power factor is only associated with alternating current, in AC system/circuits the impedance to the circuit is not only resistive, it may also have a part of inductive and capacitive reactance... That is in AC systems the total power transmitted from a source is not fully converted to useful work.. that is a fraction of the power is stored as magnetic energy in coils( transformers etc..) and electrostatic energy ( in capacitors etc..) The power that does useful work can be said as active power( P) the other fraction of total power which does not do any useful work but helps the active power to do work is termed as reactive power(Q)!! .          The above is power triangle which relate...

Did you ever thought about the condition without alternating currents?, probably no way, but we may had a thought about not having the electricity.Well its in some ways related to the same situation if we are still following the concept of direct current by Edison, because there isn't any practical methods to resolve the problem encountered in transmission session.           The success of  Rival of Edison, Nicolas Tesla is the reliability of his concept of  alternating currents for the transmission purpose.The Device for that simplifies the complexity is Transformer.Truly it was a magic in that time as a circuit transfers power between electrically isolated circuits.        A Transformer could be defined as a device which transform power between two electrically isolated magnetically coupled network without change in power and frequency. Its could be clearly understand from the definition that ...