Abstract :
Power stations used to support grid frequency must be able to operate in the part-load range so that they can supply the required power reserves. They must also be able to respond quickly within a few seconds after a collapse in grid frequency. Due to the quick reaction time needed, only gas turbines are used for this purpose. Gas turbines have a lower thermal efficiency in their lower part-load range but, if their control systems are properly designed, modern ABB gas turbines-as shown here using the GT 13E2 as an example-can, in conjunction with combined cycle power plants, meet all the requirements for frequency support capability specified in the Grid Code. A careful selection of the part-load point ensures that the gas turbine will operate at an optimum efficiency without being unduly stressed