Power system protection: the importance, requirements, and most essential elements

Posted on Oct 20, 2023 at 03:10 AM

Protecting the power system from the basic requirements of any electrical system is a high-cost investment area, so the more we want to increase the reliability of electricity, the more we need to protect it.

In the following lines, we will be learning about the primary objectives of power system protection that should be addressed, as well as the most critical requirements of it.

The goal of power system protection:

Power System Protection is a branch of electrical engineering concerned with controlling and controlling the functioning of electrical systems, in their different, simple, and complex forms, and electric circuits to maintain the stability of the power system and keep distribution and transportation networks steady.

However, the main objective is to prevent further breakdowns and problems in a system when malfunction, shortness, or diamonds occur in one part of the system.

This is done by isolating the defective section of the electrical system from the rest of the sound-associated system to prevent damage and protect equipment and components to ensure that the proper system continues to operate correctly without causing any significant damage as a result of the relatively large fault stream resulting from the defective part.

Another objective of power system protection is to continue its work without disruption under normal working conditions.

What are the most important requirements for power system protection?

Power system protection cannot prevent the flow of the fault stream or fall short of the system, but all it does is block the road in front of it very quickly to stop it. To achieve this with the required speed, the protection phases must have the following essential requirements:

• Reliability

The most essential requirement is a protection relay must-have, which means the relay remains idle as long as there is nothing wrong with the system. Still, once a fault or malfunction occurs, the relays must respond immediately and with the proper mechanism.

• Selectivity

it describes the situation in which it should operate on time because of the functioning of all phases of the power system when the failure occurs, as in some typical circumstances when the error occurs; it is possible not to operate or operate some relays with a specific time delay. Therefore, the relay must be able to detect the condition in which it should be used.

• Sensitivity

Relays must have high sensitivity to operate reliably when the error level, whether current, voltage, or phase angle, exceeds a certain specific level.

• Speed

Here lies the quality of protection, the speed of separation before the worst happens; relays must work fast enough that the occurrence of the error in one part does not affect the rest of the healthy parts.

A section of the malfunction stream may cross into the proper part since all parts are electrically connected, but the relays of this part should not work more quickly than the relays of the defective component; otherwise, an unwelcome separation of the proper system can occur.

But if the defective part relay does not work in time due to any problem or defect, the next relay must work in the proper part of the system alone to isolate the error.

By following the electrical power system protection cycle, you will learn more about the goals and requirements in this sector.

What are the most essential elements used in protecting the power system?

A wide range of electrical elements are used to protect the power system, both AC and DC, the most important of which are:

• Molten or fuse:

A component of energy protection systems, a small element with a small wire inside, melts the wire in unusual conditions when the current passing through it exceeds the value of the contemporary design.

Virtues are distinct elements of an electric power system that do not need an external power source to function like the rest of the features that require it.

• Instrument Transformer:

Achieving accurate protection of systems depends on measuring all natural and abnormal conditions of such systems correctly by measuring voltage and current transactions, whether the system is sound or problematic.

Instrument transformers act as actual transformers within the system, reducing current or voltage, depending on their function as a voltage converter or current converter, to levels that the relay can handle. In addition, the relay circuit is isolated from the high-voltage circuit of the system as a whole to protect it from damage.

If a voltage adapter is used, it connects in parallel with the line to be protected, and using a current adapter, it touches on the sequence to the line where the current will be measured.

• Relay:

Relay is a sensor due to its ability to make decisions when detecting errors, as it serves as the intellectual mind of energy systems.

The relays continuously measure the efforts and currents in the circuit and convert them into digital or similar signals, comparing them with their controlled values so that the decision is made to connect or separate the course constantly.

The two main functions of the phases are to alert the fault and make the trip as soon as it is detected.

Over the past years, relays have been extensive with limited functionality. Still, with technological and industrial development, modern relays have come in different sizes up to nanoscale and can monitor various transactions and give complete reports on the system's history.

• Circuit Breaker:

Electrical cutters are electric-powered separation/connection switches that can open and close electrical circuits safely and reliably.

In normal conditions, when there is no system defect, the protective cutter contacts are closed; once the bug occurs, the flight file activates and releases a sledge that causes the spring of closure to relax to open quickly and isolate the circuit.

Cutters are classified according to various considerations such as design, electric arc cutters, use mechanisms and voltage levels, low and high voltage cutters, and many more.

• Battery:

Batteries are significant in power system protection systems; they are used to ensure that the feeding of devices and components of the system is not interrupted, as some elements, such as relays and cutters, must be supplied with power from external sources that are not affected by breakdowns.

• Electrostatic Discharge Protection Device (ESD):

These devices protect the system and workers, collecting excess charges that will damage the protection circuit and cause disruption by discharging them into the ground.

• Surge Protection:

A flow protector or mutation protection device is a device that protects electrical equipment from sudden current increases by suppressing voltage spikes, where the device restricts excess voltage within an electrical device and keeps it below the safety threshold.

All previous elements are widely used in most protection systems and need to be studied and selected accurately and suitably when installing the system to ensure proper operation.

London Premier Training Centre offers a renewable energy integration program in which you can now register to learn more about this area in the Protection of Electrical Power Systems course.