Control of power interchange between electric systems

Claim 1

A SYSTEM FOR CONTROLLING THE POWER INTERCHANGE AMONG A PLURALITY OF TIE LINE INTERCONNECTED POWER SYSTEMS COMPRISING MEANS FOR MEASURING THE POWER FLOW OVER THE TIE LINES BETWEEN INTERCONNECTED PAIRS OF SAID POWER SYSTEMS, MEANS FOR EACH OF SAID SYSTEMS RESPONSIVE TO THE NET MEASURED POWER FLOW OVER THE TIE LINES CONNECTED TO THAT POWER SYSTEM FOR COMPUTING THE CHANGE IN GENERATION REQUIRED IN THAT POWER SYSTEM TO ESTABLISH SAID NET MEASURED POWER FLOW AT A NET SCHEDULED VALUE, FIRST CONTROL MEANS FOR EACH OF SAID SYSTEMS FOR PRODUCING IN RESPONSE TO SAID COMPUTED CHANGE IN GENERATION REQUIRED FOR THAT SYSTEM AN INCREMENTAL POWER COST SIGNAL WHICH VARIES UNTIL SAID COMPUTED CHANGE IS REDUCED TO ZERO, MEANS FOR SEPARATELY COMPARING SAID INCREMENTAL POWER COST SIGNALS OF INTERCONNECTED PAIRS OF POWER SYSTEMS, SECOND CONTROL MEANS FOR AT LEAST ONE OF SAID TIE LINES OPERABLE IN RESPONSE TO DIFFERENCES IN SAID COMPARED INCREMENTAL POWER COST SIGNALS TO VARY THE SCHEDULED VALUE FOR THE POWER FLOW OVER SAID TIE LINE UNTIL SAID COMPARED POWER COST SIGNALS ARE IN PREDETERMINED RELATION, SUMMING MEANS FOR EACH OF SAID POWER SYSTEMS FOR SUMMING SAID SCHEDULED VALUES OF POWER FLOW FOR THE TIE LINES CONNECTING THAT POWER SYSTEM TO OTHER OF SAID POWER SYSTEMS TO PRODUCE SAID NET SCHEDULED VALUE FOR THAT POWER SYSTEM, AND SEPARATE MEANS EACH RESPONSIVE TO SAID INCREMENTAL POWER COST SIGNAL FOR A CORRESPONDING ONE OF SAID POWER SYSTEMS FOR CHANGING THE GENERATION IN THAT POWER SYSTEM SO AS TO PROVIDE POWER THEREFROM AT AN INCREMENTAL COST CORRESPONDING TO SAID INCREMENTAL POWER COST SIGNAL.

Claim 2

A SYSTEM FOR CONTROLLING THE POWER INTERCHANGE AMONG A PLURALITY OF TIE LINE INTERCONNECTED POWER SYSTEMS COMPRISING MEANS FOR MEASURING THE POWER FLOW OVER THE TIE LINES BETWEEN INTERCONNECTED PAIRS OF SAID POWER SYSTEMS, MEANS FOR EACH OF SAID SYSTEMS RESPONSIVE TO THE NET MEASURED POWER FLOW OVER THE TIE LINES CONNECTED TO THAT POWER SYSTEM FOR COMPUTING THE CHANGE IN GENERATION REQUIRED IN THAT POWER SYSTEM TO ESTABLISH SAID NET MEASURED POWER FLOW AT A NET SCHEDULED VALUE, FIRST CONTROL MEANS FOR EACH OF SAID SYSTEMS FOR PRODUCING IN RESPONSE TO SAID COMPUTED CHANGE IN GENERATION REQUIRED FOR THAT SYSTEM AN INCREMENTAL POWER COST SIGNAL WHICH VARIES UNTIL SAID COMPUTED CHANGE IS REDUCED TO ZERO, MEANS FOR SEPARATELY COMPARING SAID INCREMENTAL POWER COST SIGNALS OF INTERCONNECTED PAIRS OF POWER SYSTEMS, SECOND CONTROL MEANS FOR AT LEAST ONE OF SAID TIE LINES OPERABLE IN RESPONSE TO DIFFERENCES IN SAID COMPARED INCREMENTAL POWER COST SIGNALS TO VARY THE SCHEDULED VALUE FOR THE POWER FLOW OVER SAID TIE LINE UNTIL SAID COMPARED POWER COST SIGNALS ARE IN PREDETERMINED RELATION, SUMMING MEANS FOR EACH OF SAID POWER SYSTEMS FOR SUMMING SAID SCHEDULED VALUES OF POWER FLOW FOR THE TIE LINES CONNECTING THAT POWER SYSTEM TO OTHER OF SAID POWER SYSTEMS TO PRODUCE SAID NET SCHEDULED VALUE FOR THAT POWER SYSTEM, AND SEPARATE MEANS EACH RESPONSIVE TO SAID INCREMENTAL POWER COST SIGNAL FOR A CORRESPONDING ONE OF SAID POWER SYSTEMS FOR CHANGING THE GENERATION IN THAT POWER SYSTEM SO AS TO PROVIDE POWER THEREFROM AT AN INCREMENTAL COST CORRESPONDING TO SAID INCREMENTAL POWER COST SIGNAL.