Patent ID: 8365583

Claim:
A method of testing an overspeed protection system of a powerplant, the method comprising: providing a powerplant machine comprising a shaft and an operational control system, wherein the operational control system is configured for operating the powerplant machine and comprises an overspeed protection system configured for detecting an overspeed event associated with the shaft; providing a safety control system independent of the operational control system, wherein the safety control system is configured for reducing risk associated with operating the powerplant machine; and wherein the safety control system functions as a stand-alone system independent of the operational control system; selecting a methodology for testing the overspeed protection system; wherein the methodology determines whether the powerplant machine is operating in a shutdown mode or an operating mode; determining whether the speed of the shaft exceeds a shutdown value representative of the overspeed event, if the powerplant machine is in the shutdown mode; determining whether the speed of the shaft exceeds an overspeed trip value representative of the overspeed event, if the powerplant machine is in the operating mode; changing the overspeed trip value; and determining whether the overspeed protection system would operate to trip the powerplant machine; wherein the method reduces the possibility of a trip occurring during testing of the overspeed protection system.