An electric power system includes an on-load tap changing (OLTC) transformer. The transformer includes a plurality of primary windings and a plurality of secondary windings. At least a portion of one of the primary windings and the secondary windings are inductively coupled to each other. The system also includes at least one on-load tap changer coupled to at least one of the primary windings and the secondary windings. The on-load tap changer is selectively configurable to regulate the portion of at least one of the primary windings and the secondary windings inductively coupled to each other. The system further includes at least one processor coupled to the on-load tap changer. The processor is configured to adaptively regulate a voltage set-point of the on-load tap changer as a function of an adaptive OLTC transformer power flow dependent voltage set-point characteristic.