The dual-stage fuse coordination mechanism of the primary and secondary deep fusion circuit breaker achieves a step-by-step rapid cutoff of the short-circuit current through precise coordination between the primary and secondary sides. This mechanism is not a simple two-stage series connection, but a preset logical linkage that allows the two levels to play their respective advantages at different stages to form an orderly cutoff process.
As the first line of defense, the primary side is the first to respond when the short-circuit current first appears. The deep-fuse element it uses has extremely high sensitivity and can produce a fuse action at the moment the current exceeds the threshold, and initially limit the increase in current through its own fuse circuit. The action speed at this stage is extremely fast, aiming to control the short-circuit current in the initial stage, prevent it from rapidly climbing to a peak value sufficient to damage the main equipment, and buy time for the action of the secondary side.
After the initial cutoff of the primary side, the secondary side immediately starts a deeper level of fuse coordination. The intelligent monitoring module on the secondary side will analyze the continuous characteristics and fault range of the short-circuit current while the primary side is in action, and determine whether the cutoff effect needs to be further strengthened. If it is detected that there is still residual short-circuit current or the fault is not completely isolated, the fuse element on the secondary side will act according to the preset program, isolate the circuit through more thorough arc extinguishing, cut off the possible freewheeling path, and ensure that the short-circuit current does not spread.
The collaborative logic between the two stages is reflected in the precise control of the action sequence. The action time of the primary and secondary deep fusion circuit breaker on the primary side is set to a fast response of milliseconds, while the secondary side completes the judgment and action within microseconds after the primary side is actuated. There is no obvious time interval between the two, but a step-by-step cut-off rhythm is formed. This timing design not only avoids the circuit impact that may be caused by a single strong cut-off, but also ensures the thoroughness of the cut-off through two-stage relay.
In addition, the collaborative mechanism of the two-stage fuse also realizes step-by-step control through energy distribution. The primary side of the primary and secondary deep fusion circuit breaker mainly absorbs the peak energy at the beginning of the short circuit, and uses the characteristics of the deep melting material to convert part of the electrical energy into heat energy consumption, thereby reducing the current intensity; the secondary side processes the remaining continuous energy, and releases the remaining energy safely by expanding the melting range or enhancing the arc extinguishing ability, so that the current is weakened in two stages respectively, and finally completely cut off.
At the same time, the two-stage structural design provides hardware support for coordinated action. The circuit connection method between the primary and secondary sides ensures the real-time transmission of the action signal. When the primary side is fused, its state change will be immediately fed back to the control unit on the secondary side, triggering the coordinated preparation of the secondary side; and the action of the secondary side will also confirm the cutting effect of the primary side through the reverse signal, forming a closed-loop coordination to avoid false action or inadequate action.
This step-by-step cutting process not only takes advantage of the rapid response of the primary side, but also ensures the thoroughness of the cutting with the help of the deep processing capability of the secondary side. The coordinated cooperation of the two allows the short-circuit current to be gradually controlled and weakened at different stages until it is completely cut off, thereby protecting the circuit safety while minimizing the impact of the cutting process on the power grid.
