Control and Protection Circuit for Palleling Transformers

Hi,

I am trying to modify and may be later specify a control/protection CIRCUIT for paralleling power transformers destined to be used at our substation. The paralleling is based on the master-follower-independent switching principle. On the CIRCUIT, they used a 3-position MANUAL switch with position '1' for master and '2' for follower and '3' for independent. I want to add another option of switching as above; remotely through SCADA. I have started by inserting in a 2-postion rotary switch that flips between the MANUAL and SCADA. I'm supposed to go all the way to show how switching is done within SCADA using the Normally-Closed and or Normally-Open contacts of relays. To recognize where I am facing difficulties, consider the 'master' mode of the master-follower-independent modes, implemented by a Normally-Open contact of a relay. On receiving a SCADA pulse, the relay is energized and the Normally-Open contact closes thereby switching to the master mode. Note that the contact remains closed as long as the relay is energized. However the SCADA pulse is momentary, meaning the relay is momentarily energized. I am thinking of using digital latches in order to keep the relay energized and I am wondering whether that makes a simple solution or what else should I consider?

Ron