Fault BA Yes RD-BA? Waiting for Start Message Yes Query Reply Yes BAs SD-BA SD-BA? No S-1? BA Yes RD-BA RD-BA Inform the BAs to Change Operating Mode if It Is Needed TD-BA Start Start Send a Start Message to RD-BA No Update the Power Flow Information No Query Reply Step 1 Search for Substation Bus Search for Substation Bus The End Update the Power Flow Information R-1? Operate in Island Mode Reserve Yes Yes Load Shedding Capacity Is Request Enough? Assign There There No No Restoration BA Is No AL-BA? Task to AL-BA Request Request Request the BA Forward the Request That at the Other AL-BA BA Message to Adjacent BAs End of the Tie-Line Until Find the AL-BA Reply No Information Collection Request BA Yes Request BA Refuse the Request Directly Yes The Bus Is Waiting for Restoration? Yes Island Operation? Step 2 No Request No The Request Is from Other Area? No Has Any Upstream BAs? Reply Reply to the Request Yes BA This BA Is the Substation BA? Yes Reply No BA BA Update the Message and Forward It to the Adjacent BA No BA Request BA Reply Has Found the Power Source? Yes Reply BA No In the Normal Region? No RD-BA Reply_Inform RD-BA BA Request Forward the Request Message to the Adjacent BA That Has Not Been Visited Until Find the Power Source BA Reply Assign the Restoration Task to AL-BA by Adjacent BAs Yes All AL-BAs Have Been Visited in R Region? Yes Step 3 Update the Message and Forward It to the Requester Update the Message and Forward It to RD-BA No Reply Yes BA Inform BA Inform Keep the Best Restoration Plan Update the Capacity Requirements Executive The Plan Can Restore All Loads? No Load Shedding BA Reply_Executive RD-BA The End Figure 3 The procedure of service restoration. november 2012 | Ieee ComputatIonal IntellIgenCe magazIne 69