What is a protective relay? The first line of defense for the grid

In modern society, the stable operation of the power system is very important. However, in the complex power supply network, problems such as line failure and equipment aging will inevitably appear. At this time, an "invisible hero" is needed, which is the protective relay . As an automatic control device, it can respond quickly when the circuit is abnormal, and take appropriate measures to ensure the normal operation of the entire power system.

For example, suppose a transformer in a factory has an overcurrent phenomenon due to excessive load. If it is not handled in time, it may cause serious accidents or even fire hazards. At this time, the installed protector relay(that is, we often say that the protection relay) will immediately start to disconnect the relevant circuit to avoid greater loss.

Core Principle: The Mystery Behind Current and Voltage Monitoring

So how exactly does such a magical little guy work? The answer is not complicated-it mainly accomplishes the task by monitoring the amount of current flowing in and out of the two ends of the device under test in real time. The two types of digital and electromagnetic have their own advantages:

• -Digitally use the microprocessor to calculate the collected data and then make a judgment according to the preset value;
• -The traditional electromagnetic induction law relies on the change of the magnetic field generated by the coil to trigger the action of the mechanical switch.

these two forms are suitable for use in different occasions, depending on the accuracy requirements and the cost budget and other factors, it is more appropriate to make a decision after comprehensive consideration!

Multiple protective barriers: all-round analysis of the main functional modules

In addition to the basic functions mentioned above, protector relay also has multiple high-level defense methods to choose from:

• - Overload protection : When it is detected that the working state continuously exceeds the set threshold range, it will automatically cut off the power connection to prevent the machine parts from burning;
• - Short circuit trip : If it is found that two or more conductors accidentally contact each other to form a low-impedance closed loop and instantly produce a large impact, immediately execute the emergency stop command to reduce the possibility of damage spreading.

All these independent but closely related functional units together form a complete and efficient architecture, so that any potential risks can be properly resolved.

Choosing according to local conditions-matching solutions for different industries

Considering that various industries have very different standards for power quality and safety, it is particularly important to tailor special versions for specific fields.

• For example, industrial enterprises often need product specifications that are more robust and support long-term operation in harsh environments;
• while for ordinary family households, it is more reasonable and practical to be small, simple and beautiful while taking into account the consideration of cost performance.

no matter which market segment the customer is in, as long as the specific application conditions and parameters are defined, the ideal model combination that best suits their needs can be easily found!

Future Trend Outlook: Intelligent Upgrade Drives Industry Development

with the rapid development of science and technology, the next generation of intelligent protective relays will usher in an unprecedented period of development opportunities. Imagine if the existing simple hardware facilities are further extended to expand access to the Internet platform to achieve remote control, management and maintenance and other functions will bring about what kind of convenience and efficiency improvement effect?

In addition, we can also use advanced technology such as big data cloud computing to continuously optimize the algorithm model to improve the level of prediction and prevention to achieve twice the result with half the effort. Therefore, both manufacturers and end users should keep pace with the times and actively explore and try new things so as to be invincible, friends ~