Maximizing automatic reverse power operations with LTC transformers and regulators

Advanced LTC (load tap changer) transformer & regulator controls automatically detect a power flow reversal and allow several operation options when power reversal is detected. Errors can occur in detecting power direction or in the control action selected for the condition. Such errors can result in damaging system voltages by running the tap position to its limits or by requiring impossible actions from other system components. This paper discusses these system operating conditions, methods of control direction detection, methods of determining source-side voltage, selectable operational control features and the consequences of improper choices with different system configurations/conditions