MIVI1000E00HI00 protective relay GE

MIVII1000E00HI00

In order to make the relay protection device can complete the task of relay protection accurately and timely, the following four basic requirements should be met for the relay protection that technically operates on tripping.
1. reliability
The reliability of the relay protection device refers to that when there is a fault that the relay protection device should act within the specified protection range, it should not refuse to act (also known as reliability), and in any other case that it should not act, there will be no wrong action (also known as safety).
The misoperation and rejection of the relay protection device will cause serious harm to the power system. However, the measures to improve the reliability of non-error operation and non-rejection operation are often contradictory. Because of the different structure and load nature of power system, the harm degree of misoperation and rejection is different, so the emphasis of improving the reliability of protection devices should be different in various specific situations. For example, when the system has sufficient rotating standby generation capacity, many transmission lines, and close connections between systems and between power sources and loads, the loss to the power system may be small due to the removal of generators, transformers or transmission lines by the misoperation of the relay protection device, but if the relay protection device refuses to operate when the generator, transformer or transmission line fails, the loss may be small. It will cause damage to equipment or damage to the stability of the system, the loss is huge. In this case, it is more important to improve the reliability of relay protection not to be tripped than to improve the reliability of relay protection not to be tripped. When the rotating standby power generation capacity in the system is small, and the connection between the system and the power supply and load is weak, the generator, transformer or transmission line will be cut out because of the wrong action of the relay protection device, it will cause the interruption of the load power supply, and even cause the damage of the system stability, the loss is huge, and when the relay protection device is rejected, Its backup protection can still operate, remove the fault, therefore, in this case, to improve the reliability of the relay protection device is more important than to improve the reliability of the relay protection device. It can be seen that appropriate measures should be taken to improve the reliability of the relay protection device according to the specific situation of the power system and load.
2. sensitivity
The sensitivity of a relay protection device refers to its ability to respond to faults or normal operating conditions within its protection range. The relay protection device that meets the sensitivity requirement should be able to detect the fault and respond correctly when the fault occurs within the specified protection range, regardless of the location of the short circuit point, the type of short circuit, and whether the short circuit point has a transition resistance. The sensitivity of the relay protection device is usually measured by the sensitivity coefficient, which is mainly determined by the parameters and operation mode of the protected component and power system. GB/T 14285-2006 “Technical Regulations for Relay Protection and safety automatic devices” has made specific provisions on the minimum sensitivity coefficient of various relay protection devices.
3. selectivity
The selectivity of the action of the relay protection device means that the fault element is only removed from the power system when it is operated, so as to reduce the fault scope as far as possible, so as to ensure that the trouble-free part of the system can continue to operate safely.
4. rapidness
The rapidity of the relay protection device refers to its ability to remove faults as quickly as possible. Rapid fault removal can improve the stability of concurrent operation of power system, reduce the user’s working time under the condition of voltage reduction, and reduce the degree of failure of fault components. Therefore, in the event of failure, should strive to relay protection device can act quickly.