Long-Range Backup of Protection and Breaker Failures in 0.4-kV Grids

The algorithm of a digital device for solving the problem of long-range backup of protection and breaker failures in 0.4-kV grids and simultaneous reduction of the setting for actuation of the protection of the transformers and generators feeding the grids is considered. Recommendations are given for choosing the actuation settings. The device has been tested under conditions close to field ones. The economic effect consists in prevention of fires due to fault-initiated protection failures and durable disabling of substations for repair works.