The so-called automatic reclosing device is an automatic device that automatically turns on the circuit breaker that has tripped due to a fault as needed. The power system adopts an automatic reclosing device, which greatly improves the reliability of power supply and reduces power outage losses. Moreover, this device also improves the transient stability level of the power system and enhances the transmission capacity of the line.
(1) According to the action of reclosing, it can be divided into electrical and mechanical.
(2) According to the way the automatic reclosing device acts on the circuit breaker, it can be divided into three-phase ordinary reclosing, single-phase reclosing and comprehensive reclosing.
(3) According to the composition principle of reclosing, it can be divided into electromagnetic type, transistor type, integrated circuit type, and digital type.
(4) According to the number of actions, it can be divided into one-shot and multiple-times.
(5) According to the use conditions of the automatic circuit recloser, it can be divided into single-power reclosing and dual-side power reclosing. The double-sided power supply reclosing can be divided into verified non-pressure reclosing, verified synchronous and non-verified.
Here are some selection principles of the automatic circuit recloser provided by Gopower.
(1) Three-phase ordinary one-time reclosing method
This method is suitable for 110kv and below power grids, especially for dense ring networks in centralized power supply areas, lines that can operate stably without automatic reclosing devices after line trips. It is suitable for single-sided power radiation type lines, not suitable for the outlet of large units.
(2) Single-phase reclosing and comprehensive reclosing methods
This method is suitable for 220kv and above power grids. When a single-phase ground fault occurs, the stability of the system cannot be guaranteed if the three-phase reclosing is used, or a large-scale blackout may occur in the regional system. Or, it can be used when the important load is out of power, especially the high-voltage distribution lines of large-scale generating units, when single-phase reclosing has a better effect on restoring power to the system.
(3) Verification of no pressure or verification of simultaneous reclosing mode
This method is used for lines that have power at both ends and lines that do not allow asynchronous closing. On a double-circuit line, you can directly verify that there is current on the other line to determine the same period.
(4) Non-synchronous reclosing method
There should be three or more closely connected lines between power plants or power systems operating in parallel. The inrush current generated by the non-synchronous automatic reclosing device does not exceed the specified allowable value, and the power system can quickly resume synchronous operation after reclosing. During the oscillation process caused by non-synchronous reclosing, the impact on important loads is small.