These specialized devices provide the necessary voltage levels for auxiliary equipment within electrical substations and power generating facilities. They step down the high voltage from the main power lines to lower voltages suitable for operating lighting, control circuits, protective relays, cooling systems, and other essential station apparatus. For example, a unit might reduce a 13.8 kV supply to a 120/240V distribution system serving the station’s needs.
Their reliable operation is critical for maintaining the overall functionality and security of the power grid. A failure in the supply to these auxiliary systems can lead to a cascading series of events, potentially causing a blackout. Therefore, these units contribute significantly to system stability and operational resilience. Their use has become standard practice in modern power systems since the mid-20th century, evolving alongside advancements in electrical engineering and power distribution methodologies.
