Today, the metropolitan medium voltage cable network includes many switchgear / ring backbone units (RMUs) and transformers in distribution substations that control the distribution of electricity through the cable lines. Distribution substation RMUs can be installed in their own buildings, in a compact transformer station building, or they can be installed in a dedicated electrical room in a larger building, such as a shopping center.
To minimize tripping times and improve SAIDI (Average System Interruption Duration Index) and SAIFI (Average System Interruption Rate Index), indoor control cabinets are used to provide on-line control of transformers, RMUs, circuit breakers and disconnectors. Operational control allows you to receive information about the distribution substation connections in real time. In the event of damage to the power system, control cabinets activate control functions to execute commands over reliable communication lines.