1. Current quick-break protection, time-limited current quick-break protection, and time-limited overcurrent protection. The current quick-break protection is simple and reliable, and the action is rapid; however, the full length of the line cannot be protected, and there may be no protection range when the line is short or the operation mode changes greatly.
2. The time-limited current quick-break protection structure is simple and reliable, and can protect the full length of the line; but it cannot be used as backup protection for adjacent components (next line), and is greatly changed by the system operation mode.
3, the time-limited overcurrent protection structure is simple, reliable, not only can be used as the near backup of the line (sometimes as the main protection), but also can be used as the far backup of the next line; but the action time is long, Moreover, the closer to the power supply terminal, the greater the time limit for its action, and the failure of the power supply terminal cannot be quickly removed.
The wire path is usually protected by three-stage current protection, which is protected by the untimed current speed section. One section of protection, with time-limited current quick-break protection as the second-stage protection, time-limited over-current protection as the third-stage protection, and no-time-limited current quick-break protection as the main protection of the first section of the line, it moves quickly, but cannot protect the entire line Long.
With time-limited current quick-break protection as the near backup of the first section of the line, the main protection at the end of the line, the far backup of the first line adjacent to the next line, it can protect the full length of the line, but Can not be used as a neighboring next line completely far backup, time-limited over-current protection as the near backup of the line, adjacent to the next line of the far backup, it has a large protection range, sensitive, but long time to cut off.