SPS
The Synchronous Parallelism Supervisor (SPS) is a device used for controlling and supervising the parallel operation of power transformers equipped with on-load tap changers (OLTC), which must operate at numerically equal tap positions to achieve the lowest possible circulating current between the parallel windings. Its control philosophy is based on the master-slave (or master-follower) principle, where one of the transformers is designated as the master and the others as slaves. Thus, all tap change commands made by the master must be mirrored by the others in order to maintain tap alignment. If this does not occur, the system will remain blocked and an alarm will be triggered.
