Electric power generator selection, shedding, and runback for power system stability

A method for managing an electric power delivery system comprising a plurality of generators, the method comprising:

• determining a plurality of generator groups, each generator group comprising a unique set of one or more of the plurality of generators;
• determining excess generation (EG) by the electric power delivery system, based on load information received through a signal from the electric power delivery system;
• if EG is less than or equal to runback capacity (RC) of the plurality of generators:
• selecting a generator group of the plurality of generator groups according to a predetermined ordering;
• and
• until EG is greater than a runback selected (RS), where RS is a sum of a runback capacity of a group (RCg) for selected groups:
• selecting a next generator group of the plurality of generator groups according to the predetermined ordering;
• and
• setting RS equal to itself plus the RCg for the next selected generator group;
• if EG is less than or equal to RS:
• setting a runback set point for each generator of the selected generator group according to a proportion of RC within the generator;
• and
• sending a signal by a communication interface to runback each generator of the selected generator group according to the runback set point.

A system for managing generation runback on a microgrid, comprising:

• a contingency breaker to receive an over-generation condition signal indicating that the microgrid is generating excess power beyond power being consumed collectively by loads connected to the microgrid, wherein the contingency breaker trips based on user preferences and the over-generation condition signal;
• an intelligent electronic device (IED) in communication with the contingency breaker and a plurality of generators on the microgrid, the IED to:
• determine a plurality of generator groups, each generator group comprising a unique set of one or more of the plurality of generators;
• calculate excess generation (EG) on the microgrid;
• if EG is less than or equal to a runback capacity (RC) of the plurality of generators:
• select a generator group of the plurality of generator groups;
• and
• until EG is greater than a runback selected (RS), where RS is a sum of a runback capacity of a group (RCg) for selected groups:
• select a next generator group of the plurality of generator groups according to a predetermined ordering;
• and
• set RS equal to itself plus the RCg for the next selected generator group;
• if EG is less than or equal to RS:
• set a runback set point for each generator of the selected generator group according to a proportion of RC within the generator;
• and
• send a signal by a communication interface to runback each generator of the selected generator group according to the runback set point.