What is relaying and for which it is intended

We all know that in addition to the home wiring has a high-voltage power lines, these should transfer energy from the substation to the substation. And if to protect the household wiring we'll set the machines, RCD, and the like, what protects the equipment at the substations themselves? Not unpretentious same machines and circuit breakers. In this article I will introduce you to relay protection and in general will tell how it works.

What is relaying

Thus, the relay protection and automation - is a collection of many devices designed for the early detection and disabling the total damaged area electrical network in order to maintain normal operation all of the remaining power system.

For what purpose is the relay protection

Assignment of relay protection lies in the rapid shutdown of the damaged portion of the power system to ensure the safety of the equipment is quite expensive. After all, if time does not eliminate the short circuit, it is possible to damage or even destruction of equipment worth tens of millions of rubles.

Requirements to the relay protection

So, to relay protection presented four main requirements, namely:

1. Selectivity. This means that the short-circuit protection must disable only the damaged area, and the remaining parts of the system are required to continue their work.

A requirement that can be divided into two sub-items:

- the relative selectivity. By thereof include the maximum current and distance protection.

- absolute selectivity. This category includes absolutely all kinds of differential protection.

2. Reliability. This means that protection must perform their security functions throughout the entire period of operation and under all environmental conditions.

3. Performance. It is also extremely important requirement, because of the speed off corrupted network element or portion dependent stability of the whole system. And the faster you remove the equipment, the less damage will be inflicted to him.

4. Sensitivity. Protection must respond to any deviation from the normal mode even when the minimum set of parameters is exceeded, the lower threshold of security elements exposed setpoints.

To say in simple language, the protection relay is used to monitor the performance of equipment and rapid turn it off in case of an emergency situation.

Just all the relay protection elements can be divided into three types

Starting bodies. Responsible for the continuous monitoring of operating parameters of the entire system in the case of deviation from these values ​​of settings (short circuit) is carried out starting measuring elements.

Measuring elements. Determine the type and location of the damage and, if necessary, give the command to the action of a particular protection.

The logical part. Just run launchers bodies and processing data of the measuring bodies, performs a certain sequence of actions to disable the damaged elements or automatically re Inclusion.

conclusion

Protection - is primarily a well-established set of blocks and relays are designed to discharge the same protection of the equipment and ensure uninterrupted and quality power supply end user. Thanks for attention.