In our country, during medium and low voltage busbar short circuit failures, the main causes of damage to key equipment and personnel are arc flashes. However, the majority of our medium and low voltage busbars do not have rapid busbar protection in place, but rather only simple arc extinction devices and transformer backup protection. These protections have low intelligence and slow response times, often extending the time it takes to isolate faults, further exacerbating the extent of equipment damage and potentially causingA catastrophic "fire spreading across camps" incident occurred, impacting the operation of a transformer, thereby affecting the safe operation of the entire power grid.

Our Arc Flash Protection System is a newly developed, innovative technology that combines the practicality and high reliability of arc flash protection systems from abroad, tailored to the domestic market. It integrates industry testing and protection configuration guidelines, featuring unique, cutting-edge technology. Utilizing dual criteria of arc detection and overcurrent detection, it boasts rapid protection response and high reliability.

1.2Causes of Arc Light

There are many causes for arc fault short circuit failures in switch cabinets, typically categorized into the following five types:

Insulation Failure：Primarily, the insufficient creepage distance of the insulation materials within the cabinets did not meet the enhanced insulation requirements, leading to insulation failures in dirty and humid environments. Additionally, due to material defects in the insulation materials, circuit breakers that have been in operation for a long time may experience insulation aging under the influence of strong electromagnetic fields, potentially causing insulation damage and resulting in faults.

2) Poor current loop：Due to insufficient contact sections, the fastening bolts became loose, the cabinet push-button contacts were not making good contact, leading to overheating and sparking when high currents flowed, which in turn caused phase-to-phase arcing and relative breakdowns, etc.

Entry of Foreign Objects：If small animals (such as mice) enter the interior of the switchgear cabinet, or if maintenance personnel leave tools inside the cabinet after completing their work.

4) Misinterpreted the operation：If the spacing is incorrect, there is a mistake in operation, the work area has not been grounded, or the work area has not been tested for electricity, etc.

5) System-related reasons：As system capacity increases, grounding methods change, cable applications rise, improper configuration of protective and self-control devices, and system resonance overvoltage occur.

Hazards of Arc Light on March 1st

Arcing power inside the switchgear can be as high as100MW of energy produced by arc combustion exponentially increases with the burning time of the arc and the change in short-circuit current (as shown in the figure below). The high temperatures and pressures generated by the combustion will gradually destroy components, copper bars, and rows of switchgears. The bright arcs and toxic gases also pose significant harm to human health.

To ensure that the equipment is not structurally damaged, it is essential to minimize the time for removal.

The following is an assessment of various arc durations and the corresponding levels of damage to equipment, as presented by foreign sources:

1.4Arc Light Protection SystemFunction and Application Fields

A: Arc Light Protection System, which serves the following functions:

Reduce or mitigate the harm of arc light to the human body.

Reduce or mitigate the damage to equipment caused by arc fault short circuits.

To prevent transformer instability due to nearby busbar faults and extend the transformer's lifespan.

Reducing the arc fault clearing time to prevent major losses by avoiding the impact on the station's DC system.

Minimize downtime due to arc fault, and restore power supply more quickly.