Alright. So welcome to the blog video and in this blog, we're going to be going over
the Time Current characteristics for Selective Coordination, so let's get started.
So this is a blog that AllumiaX had written up and in this blog we will go over the tcc curves required
and the layout of the tcc curve in order to do something like a selective coordination curve.
So let's get started. A time current characteristic curve plays a significant role in achieving proper protection
coordination among the electrical safety devices and we can learn more about this
learn more as we cover basics of power system protection, tcc's for the solid state and thermal magnetic trips
and the importance the procedure and the rules of selective coordination here.
That's what we're going to learn in this blog, so let's get started.
So the objective of a power system protection.
Now the primary objective of a power system protection is to sense the fault for any abnormal conditions which may cause
the system to malfunction or cause complete outages of power and isolate it from the healthy section.
Studies are required for protecting the crucial power system equipment and selective
and protection coordination is done with the help of time current curves tcc's in short.
In this article discusses the significance of power protection coordination and how the time current curves are used for the purpose of selective coordination.
Now this is very important anyone who is familiar with power system needs to understand tcc curves
and those who are not familiar with power systems this is a good idea to really hone in and understand how it works out. Right?
So let's get started.
Now the principles of power system protection. When designing a power system protection scheme
an engineer must pay attention to the following characteristics so that our protection system provide optimum functionality.
and these are the characteristics of any sort of a protection scheme
very generalized very important to understand the the terminology involved. Right?
So we have a sensitivity. Protection system equipment should be sensitive in accurately detecting all kinds of faults
so what we mean here is that when a fault occurs whether it's a phase fault or a ground fault
the breakers or the relaying system whatever the protected devices should be sensitive to that fault
they should be able to detect and you know operate for that type of fault.
so that's what we called sensitivity characteristic and then there's a speed.
speed is tripping or cutting the supply of the healthy section.
So what we mean here is that we got to make sure that
our protection system or relaying system is very fast that it not only detects the fault but it also operates so quickly
that it doesn't cause the fault or whatever the abnormality is doesn't cause any sort of a cascading out
so it should be very fast and then there's the economics
so that means it should be less expensive and should not cost greater than 25% of the overall cost.
An economics is just you know we can add a lot more goodies in the protection scheme but there is a cut-off point
a point where we say hey this is getting above and beyond or
this is getting over the top from what the actual needs are.
So every system has a need and so economics also plays in into that need.
Okay, simplicity.
Simplicity means should not make the overall system too complex
and what we mean here is that it needs to be as simple so that the operators
and the troubleshooting methods are easily been easily taken care of. Right?
It should be very simple and then we have selectivity and this is very important.
Identifying the correct faulty part so that the least parts get affected.
For example, A university has its main breaker and each department has its own breaker right on feeder breaker
and suppose if a fault occurs in the department it should not trip the main breaker of the university
instead the main breaker of that department should trip. So what we mean is that
the breaker that's the closest to the fault that's protecting that you know the closest to that department
should actually operate not things that are upstream of that.
right so that's what selectivity means is that we're isolating that faulty area
as closely as possible so that other areas of the system does not get affected.
So that's the introduction I suppose to this blog and this is the first video so stay tuned
and we're gonna continue to go through this blog together. Thank you !!