Protection device with communication bus fault diagnosis function, system and method

摘要

The present invention proposes a method for diagnosing faults on a communication bus used to transmit zone selective interlocking (ZSI) signals in a power distribution network. The method comprises: configuring interfaces of all protection devices connected to the same communication bus (BUS1, BUS2) to be input ports within a first diagnosis time period (Ts); at each protection device connected to the communication bus, detecting an input signal received by the input port thereof; if abnormality is detected in the input signal, the protection device issuing a first alert associated with the corresponding interface.