The Structure of Traditional Power Systems
Part 1a: The Basic Structure of Power Systems
This is the first part of Topic 1: The structure of power Systems
and in this part, we will give you a
high-level overview of the basic infrastructure
on which the electrical power system is built.
This video series will focus on Transmission & Distribution system, and it will introduce you to the basic elements of the system used to transmit electric power.
Traditional power plants generate electricity,
then this electricity is transferred through the transmission system and then
distributed to different consumers that use electricity for different purposes.
Collectively, the whole system involved in power delivery is known as the Transmission and Distribution (T&D) system.
So, the structure of Power Systems comprises of numerous components, like Generating Stations,
High Voltage Power Transmission Lines, different types of Transformers, Substations,
Distribution networks and feeder schemes, Protection Devices, etc. and
We are focusing subjects related to T&D systems specifically in this series.
Now returning back, let’s draw a representation of a traditional power system.
Immediately after traditional power generation, we have the transmission system.
The transmission system is a 3-phase network.
We use the term network when we have more than one paths between any two points,
since it connects a power source and load area through multiple routes.
The main function for which the transmission system is responsible for,
is to deliver bulk energy from the Generation side to the consumer end.
Furthermore, it provides multiple links for the interchange of energy
among different interconnection points
Then there comes the sub-transmission system.
It steps down the voltage to a lower voltage level,
some of the power through here is directly supplied to heavy industries
and a few large consumers,
while the remaining power is delivered to the distribution system.
The sub-transmission system is followed by the distribution system.
The structure of this system is different
as compared to the sub – transmission system,
in the distribution system, the voltages are stepped down even further,
the number of branches is much higher and circuit lengths and configurations
is different from one application to another.
It is divided into primary distribution consisting of the feeder and lateral levels
and secondary distribution system connecting
mostly to small commercial and domestic consumers.
Here you can see that power must travel
through different lines. Between any two major
segments of lines, we have substations.
Substations change the voltage levels at the
junction of two segments.
We will define the division of transmission and
distribution system based on these voltage
levels in our next video.
The main component of a substation is a
transformer, which is used either for stepping
up the voltage or to step down it.
To learn more about transformers,
we recommend that you watch our transformer series.
In the next video, we will go deeper into the
different voltage levels and equipment
associated with the power infrastructure.
Here are some of the References for this topic.