The safe operation of the power system protection device mainly depends on maintenance, so the protection device should meet the following requirements:

(1) Selectivity: When the system can fail, we are required to protect the working device and only remove the faulty equipment to ensure that the fault-free equipment needs to continue to develop and operate, so as to minimize the scope of power outages and achieve the purpose of selective actions. The six-phase relay protection tester can independently complete device testing in professional fields such as microcomputer protection, relay protection, excitation, measurement, and fault recording. It is widely used in scientific research in electric power, petrochemical, metallurgy, railway, aviation, military and other industries. Production and electrical test site.

(2) Fastening: After the system fails, the failure can not be quickly eliminated, which may cause the failure to expand. If the voltage is greatly reduced when a short circuit occurs, the user's motor near the short-circuit point slows down or stops due to the braking speed, and the user's normal production will be destroyed; On the other hand, when the generator is short-circuited, it will not be able to deliver power, which will cause a stable failure of the power system.. Third, when a short-circuit occurs, the faulty equipment itself will pass a relatively large short-circuit current, and the equipment will be seriously damaged due to external forces and thermal effects. The longer the short-circuit current passes, the more serious the equipment damage. Therefore, after the power system fails, the relay protection device should act as soon as possible to eliminate the fault..

(3) Sensitivity: The protection device should be able to accurately respond to faults and error conditions. This means that not only the sensitive protection operation, the three-phase short-circuit metal in the large working mode, but also the large resistance to the transition through the two-phase short-circuit mode in the small and the operation, but also has sufficient sensitivity and reliable operation.

(4) Reliability: The reliability of a set of environmental protection work devices is very important, that is, when failures can occur within the scope of its protection, it should not be rejected due to its own defects. If it does not belong to its action, it should not malfunction. Otherwise, the investment of unreliable protection and control devices can itself develop into the root cause of China's expansion of production accidents and direct impact on safety accidents.