METHOD FOR TESTING AN OVERSPEED PROTECTION APPARATUS OF A SINGLE-SHAFT SYSTEM

摘要

A method for testing an overspeed protection apparatus of a single-shaft system that includes: a) operating the system at nominal speed and under electrical load, wherein the load is selected to be low enough that, after dropping the load, the speed of the system rises such that the speed remains below steam turbine threshold speed lower than gas turbine threshold speed, such that first overspeed protection is triggered when the speed of the steam turbine reaches the steam turbine threshold speed, and second overspeed protection is triggered when the speed of the gas turbine reaches the gas turbine threshold speed; b) dropping the load; c) increasing the mass flow of the steam introduced into the steam turbine and/or of the fuel introduced into the gas turbine such that the speed of the steam turbine reaches the steam turbine threshold speed; d) testing whether the first overspeed protection is triggered.