New Requirements for Relay Protection Devices
1. Simplification
With the development of relay protection technology and the increasing requirements of power systems for protection devices, the functions and structures of relay protection devices are becoming more and more complex. Ideally, the protection performance would continuously improve, but overly complex structures can bring great difficulties to device debugging and maintenance, which instead reduces actual performance.
It should be noted that in computer-based protection devices, protection functions are achieved through software design, and adding functions does not require additional hardware. However, if the functions are too complex, it may lead to a situation where focusing on one aspect causes neglect of another, and setting becomes difficult, resulting in poor practical application effects.
Therefore, with the continuous development of protection technology, electronic technology, and computer technology, the functions and structures of relay protection devices should pay attention to simplification. Some functions that rely on precise calculations for setting should be introduced with caution.
2. Adaptability
Relay protection devices serve the safe operation of power systems. Some protections are designed so that their operating characteristics are related to the power system's operating mode or fault state. Designers hope that when the system's operating mode or fault state changes, the protection's operating characteristics will shift towards improving the device's working performance, which is adaptability.
In fact, the adaptability of protection devices has been utilized for a long time. For example, inverse-time overcurrent protection has a certain degree of adaptability; line inverse-time overcurrent protection can adapt to the fault location to improve the selectivity of protection device actions, and motor inverse-time protection can adapt to the allowable heating condition of the protected motor.
With the development of power systems, the composition of protection devices has become increasingly complex, and their operating characteristics are greatly affected by changes in the power system's operating mode. Therefore, simplification and adaptability will become issues that relay protection workers must consider.
