IEEE 1865.1:2019 pdf free download – IEEE Standard Specifications for Maintenance and Test of DistributedControl Systems in Thermal PowerStations: Maintenance and Testing
electrical control system (ECS): A control system serving for operation,interlock, display, and alarmingof switchgears and synchronization devices of the auxiliary power system and grid-connection system. Thecontrol scope of the electrical control system covers the electrical system of each unit and commonelectrical system.
emergency trip system (ETS):An automatic control system that takes appropriate measures to deal withthe abnormal situation occurring during operation of turbine，and shuts down the turbine when theabnormal situation evolves to potentially endanger equipment and personnel.
fast cut back (FCB): A control measure to keep the boiler working when load rejection occurs on a turbineor generator.According to the operating requirements of a turbine following FCB, there are two operatingmodes: 1) the unit operating independently with auxiliary power,2) steam turbine being stopped while theboiler is not stopped.
gas turbine control system (TCS): The system that fulfills automatic control of various operatingconditions of gas turbinec, i.e. automatically maintains the speed, load, temperature, and other parameters ofgas turbine within the specified range.
overspeed protection control(OPC): An overspeed control function,which can be realized byacceleration restriction or on-off control. In the former case，when the turbine starts to accelerate, anoverride command will be given, and the governing valve (GV) and intercept valve (IV) be closed. Whenthe acceleration falls to zero, the normal speed control loop will function to maintain the turbine at normalspeed. In the latter case, when the speed of the turbine rises to 103% of the rating, the GV and IV will beclosed automatically, and when the speed restores back to normal, these valves will be opened again. Thisprocess will repeat until the normal speed control loop can maintain the turbine at the normal speed. Theseitwo control methods may be used in combination.
overspeed protection trip(OPT): A function of the turbine protection system, which will close the mainsteam valve (MSV), governing valve (GV), reheat stop valve (RSV), and intercept valve (1V) quickly toautomatically trip the turbine when the speed of turbine surges to a certain value.
primary frequency correction(PFC): A function of coordinated control system (cCS), which responsesto grid frequency correction requirements by means of ratio control, refers to the automatic control processin which the control system of generator unit in a grid automatically increases or decreases the active powerof the unit to stabilize grid frequency when grid frequency deviates excessively from rated frequency.
protective grounding: The connection of metallic enclosures and circuit reference points of relevantequipment of the control system to earth, in order to 1) form a low-impedance discharge path for faultycurrent and high-frequency noise,2) maintain the said enclosures at the same potential as the carth,3)avoid such hazards as lightning strikes, current leakage, and electrostatic discharge(ESD), and 4) protectoperators from clectrical hazards, thcreby cnsuring human and cquipment safety.
run back(RB): The control functions for main auxiliary machine failures, which rapidly reduce the unitload when part of the main auxiliary machines (such as feedwater pumps, forced draft [FD] fans, induceddraft [ID] fans, etc.) fail and withdraw from work, and the unit cannot carry the current load.
system grounding: The connection of the grounding point of a distributed control system(DCS)(a zerovoltage reference of circuit) with the grounding device (or electrical ground) via conductors of an effectivesectional area to help ensure that DCs can withstand the overcurrent and discharge of overcurrent to earthwhen signals transmitted to the DCS, power supply, or DCS itself become abnormal.