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The composition and requirements of relay protection
- Nov 30, 2017 -

The relay protection consists of the input part, the measurement part, the logical judgment part and the output part.The field signal input is generally required to carry out the necessary preprocessing, such as isolation, level conversion, low pass filtering, etc., so that the relay can effectively check the physical quantities of each field.Measurement signals to convert logic, according to the size of the measurement part of the output, nature, logic state, output, order information, such as combination according to certain logical relationship operation finally determined to perform an action, performed by the output part of the final task.

The basic requirements of relay protection should meet the requirements of selectivity, speed, sensitivity and reliability.When selecting the protection device, the fault device can only be removed from the power system, so as to minimize the scope of power failure and ensure that the fault-free parts of the system operate normally.Quick sex refers to short-circuit fault protection device should be removed as soon as possible, its purpose is to raise the stability of the system, so as to reduce the damage rate of the equipment and wire lines fault, narrowing the scope of is influenced by fault, improve the automatic reclosing and automatic backup device put into effect.Sensitivity refers to the ability to respond to a failure or abnormal operating condition within the scope of protection.Reliability refers to the reliability of the relay protection device when it occurs in the protection range.