Isochronous load sharing principles for an islanded system with steam and gas turbine generators

A liquefied natural gas facility in the United States is being expanded to allow liquefaction of natural gas and export of liquefied natural gas while keeping intact the existing import facilities. This means adding more loads and steam-based generation to the existing gas turbine generator portfolio. The upgraded system will feature six gas turbine generators and two steam turbine generators in an islanded plant with no grid connection. This paper reveals the fundamentals of how the plant performs isochronous load sharing in an islanded power system with various makes and sizes of generators (steam and gas turbines). The paper details the decentralized generation control system interface methodology with automatic speed governors and voltage regulators. It also presents some topics that are crucial for industrial power systems, especially in islanded configurations, as well as the transient simulations performed in a controlled lab environment to analyze system stability and help finalize the generator modes of operation.