Primary and system protection for an electric power delivery system

Abstract

Primary protection relays and an integrator disclosed for providing primary protection and secondary applications for an electric power delivery system. The primary protection relays obtain signals from, and provide primary protection operations for the power system, and may operate independently from the integrator. An integrator receives signals and status communications from the primary protection relays to perform secondary applications for the electric power delivery system. The secondary applications may include backup protection, system protection, interconnected protection, and automation functions.

What is claimed is: 
     
         1 . A system for providing primary and system electric power delivery system protection, comprising:
 a first primary protection relay and a second primary protection relay to provide primary protection to the electric power delivery system, each of the first and second primary protection relays comprising:
 a power system signal input for receiving electric power delivery system signals; 
 a protection element to determine a status of the electric power delivery system using the electric power delivery system signals and assert a protective action command when the status is outside of a predetermined operating parameter; 
 a protective action output for transmitting a protective action command to be performed by primary equipment of the electric power delivery system; and, 
 a communications output to transmit the power delivery system signals and status; 
   an integrator in communication with the first and second primary protection relays to receive the power delivery system signals and status from the first and second primary protection relays, comprising:
 a processor executing computer instructions for electric power system monitoring, the instructions comprising secondary applications using the power delivery system signals and status to determine an electric power delivery system condition and assert a command based on the electric power delivery system condition. 
   
     
     
         2 . The system of  claim 1 , wherein the secondary applications comprise a backup application. 
     
     
         3 . The system of  claim 2 , wherein the backup application is redundant to the protection element. 
     
     
         4 . The system of  claim 3 , wherein the backup application comprises a time delay to allow the protection element to operate before the backup application asserts the command. 
     
     
         5 . The system of  claim 2 , wherein the backup application comprises a bus backup application. 
     
     
         6 . The system of  claim 2 , wherein the backup application comprises a feeder backup application. 
     
     
         7 . The system of  claim 2 , wherein the backup application comprises a transformer backup application. 
     
     
         8 . The system of  claim 1 , wherein the secondary application comprises a fast bus transfer application, and the command comprises opening a breaker of the electric power delivery system, and closing a switch of the electric power delivery system. 
     
     
         9 . The system of  claim 1 , wherein the secondary application comprises a breaker failure application, and the command comprises opening a specified breaker of the electric power delivery system to remove power from a faulted feeder that includes a failed breaker. 
     
     
         10 . The system of  claim 1 , wherein the secondary application comprises a cable differential application, the condition comprises determination of a current differential, and the command comprises opening a breaker to remove power from a section of the electric power delivery system. 
     
     
         11 . The system of  claim 1 , wherein the secondary application comprises electric power delivery system automation. 
     
     
         12 . The system of  claim 1 , wherein the integrator comprises computer instructions for resampling and time aligning the electric power delivery system signals from the first and second primary protection relays, and using the resampled and time-aligned electric power delivery system signals in the secondary applications. 
     
     
         13 . The system of  claim 1 , wherein the integrator is configured to perform the secondary applications in parallel with operation of the protection element of the first and second primary protection relays. 
     
     
         14 . The system of  claim 1 , wherein the first and second primary protection relays are configured to maintain operation of the protection element upon loss of communication with the integrator.