News Detail

1. Automatic reclosing function:
Improve the power distribution stability, improve the information reliability of the system software running side by side, increase the transmission volume, and correct the faulty power failure caused by the circuit breaker organization or the malfunction of the microcomputer protection.
2. The step-down transformer without switching power supply on the low-voltage side must be equipped with automatic reclosing equipment.
3. The main purpose of starting the reclosing if the power switch parts do not match is to prevent the power switch from jumping or accidentally touching it.
4. Reclosing is generally not installed on key electrical equipment such as busbars and transformers to avoid damage to machinery and equipment.
5. The step-down transformer without switching power supply on the low-voltage side must be equipped with automatic reclosing to improve the stability of power distribution.
6. Automatic reclosing operation, the delay is 0.5s~1.5s, and the minimum is 0.3s~0.4s.
7. The three-phase reclosing posture period should exceed:
After the circuit breaker is powered off, the load motor reports the current time to the common fault point; the magnetic blowing time at the fault point and the dispersion time of the surrounding materials; the circuit breaker and the actual operating organization return to normal, and the time to prepare for the posture again in advance; the power-off time of the device.
8. The time limit of single-phase electric reclosing position should also take into account the possibility of wiring components and microcomputer protection to remove common faults and the hazards of submerged current in different time periods.
9. The arc extinction rate of single-phase power outage of 220kV transmission and distribution lines is mainly determined by the submerged supply current. 10. The reason for the submerged current supply:
Tip discharge (improves the DC voltage according to the current given by the two-color capacitor); magnetic effect of the current (improves the phase load current according to the current caused by mutual magnetic induction).
11. The capacitor reclosing can only be reclosed once, and the charging time of the capacitor battery is 20~25s.
12. In the automatic reclosing, the function of the rear memory component is to expand the single pulse.
13. The reclosing time includes the setting value time of the reclosing and the original reclosing time of the circuit breaker.
14. Three-phase recloser is used for 110kV lines, single-phase electrical reclosers are used for 220kV and above lines, and comprehensive reclosers are used for 220kV and above empty lines. This is due to the fact that the circuit breaker of 220kV and above adopts a phase-separated practical operation organization.
15. Single-phase electric automatic reclosing is not easy to cause overvoltage.
16. When the short-circuit fault at the entrance and exit is a common fault, the azimuth characteristic impedance automobile relay has the least probability of malfunction.
17. The current phase selection components are assembled on the power source side, and the low voltage phase selection components are assembled on the small switching power supply side or the electrical measurement side.
18. The recloser is equipped with synchronous metrological verification and no-voltage verification. One side is installed with no-pressure metrological verification, and the other side is only installed with synchronous metrological verification.
19. Single-phase electric recloser or integrated recloser is connected to 2 key terminals for microcomputer protection: N terminal is connected to the maintenance of the part-time phase operation that can still continue to work, and the M terminal is connected to the part-time phase operation. There is a possibility of malfunctioning maintenance. When the reclosing is in operation, the M terminal is turned off after the maintenance delay time; when the circuit breaker is reclosed, the maintenance is repaired according to 0.1s.
20. The part-time phase-locked control loop has a certain delay time in the comprehensive reclosing to prevent the harm of the transient process during common faults.
21. Application fields for acceleration before reclosing: 35kV and the following direct distribution lines drawn from power stations or distribution stations.
22. Application fields of accelerated reclosing: 110kV and above power grids or closing lines of key loads.
23. After reclosing, speed up the maintenance of the posture of the second stage, and sometimes it can also speed up the maintenance of the posture of the second stage.
24. When the double-circuit line is in operation, the reclosing cannot be accelerated after an instant, otherwise it will easily cause the reclosing to malfunction.
25. When checking the synchronous reclosing, it is not used and then accelerated.
26. The parallel-plane line reclosing adopts the current operation method of checking the adjacent line, and its proper wiring should be connected in series with the normally closed point of the adjacent line current automobile relay in the operation control circuit of the reclosing.
27. The selection criteria of the reclosing and disconnecting point is to balance the capacity and load of the power station as much as possible.

Post time: Apr-24-2022