Arc protection

Bus differential protection

Overcurrent/arc double criterion，concise, unique, reliable

The system needs to consider CT ratio, characteristic matching, saturation, disconnection and many other factors.

Passive light sensor，optical fiber transmission arc signal，not subject to electromagnetic interference

Copper wire transmission current signal，anti-electromagnetic interference is relatively poor

Whole set of action time ≤1ms

The entire set of action time is generally required≥20ms

Each system can accommodate 36 medium voltage switchgears (considering the configuration of three probes per switchgear)

Generally accommodates up to 24 feeders

The control logic is programmable, which is convenient for all kinds of bus wiring and operation mode changes, and can be fault-located.

When the operation mode is changed, the related operations of protection are complicated, and the fault cannot be located.

Flexible installation, whether it is a new project or a retrofit project

Need special protection level CT, not only big investment, but also difficult for reconstruction projects