Tricky but Easy Electrical Engineering!
In this post we will discuss about the feature of Harmonic Restraining feature of Differential Protection. First we should know why Harmonic Restraining is needed? Suppose we are going to energize the Transformer, obviously the Transformer will have an Inrush current which is around 6 times of full load current. Refer “Transformer Inrush Current” for … Read more
As discussed in the post “Transformer Differential Protection”, differential protection is supposed to operate for the internal faults or for the zone of protection it is intended for. Differential protection is not supposed to operate for a through fault. Through fault means a fault outside the zone of protection. Thus as discussed in earlier post, … Read more
Basically 33 kV / 11 kV is used for distribution of power at the substation and 66 kV / 11 kV is also used for the distribution. But whether to use 66/11 kV or 33/11 kV depends on many factors. Following are some of the factors which are taken care for the selection of voltage … Read more
Harmonic voltages and currents in a Power System are a result of non-linear electric loads. In a normal AC Power System, the current varies sinusoidally at a specific frequency, usually 50 or 60 Hertz. When a linear electrical load is connected to the system, it draws a sinusoidal current at the same frequency as the voltage, … Read more
Dynamic Braking: Apart from Regenerative Braking, another method of reversing the direction of torque and Braking the motor is dynamic braking. In this method of braking the motor which is at a running condition is disconnected from the source and connected across a resistance. When the motor is disconnected from the source, the rotor keeps … Read more
In the last post “Need for Electrical Braking in Electrical Drives“, we discussed the various reasons which call for Electric Braking. Brakes are used to reduce or cease the speed of motors. Braking of Motor can be classified into three types: Regenerative Braking. Plugging type Braking. Dynamic Braking. In this post we will focus on … Read more
There are two types of Braking: i) Mechanical Braking and ii) Electrical Braking. In Mechanical Braking the speed of the machine is reduced solely by mechanical process but Electrical Braking is far more interesting than that because the whole process is depended on the current and torque directions. We can say that it is the process … Read more
This may come in our mind that what exactly will happen if we operate a DC Motor at a speed more than the rated speed. In fact, the thermal capacity of the motor decides at what speed it can run and for how long. There is always a safety factor considered in the design which … Read more
As all of us know that these days all PSUs recruit as per the GATE rank so it is very important to secure a good rank in GATE Exam. I will strongly recommend to study with a proper strategy to have a great rank. I will soon post on how to make your strategy for … Read more
In an Aeroplane, it is only a single wire wiring which carries positive charge to all the systems and electrical units. The Aeroplane body functions as the negative path. This is why all parts of an Aeroplane are always connected with electrical bonding strips. This keeps the complete Aeroplane in a uniform level of charge … Read more