Performance and design of generators for combined cycle power plants

In various countries there is a trend away from nuclear power plants. This change if oriented to power plants where the size of the turbogenerator units is below 200 MW. These power stations combine the gas and steam turbine cycles and offer the highest efficiency and subsequently the best utilisation of fuel. All components, including the generators, that have a cycling duty with high number of working hours, are optimised to achieve longer service life and enhanced reliability for capital goods. Besides, for more economical operation of the plants, the electrical efficiency of these machines must be very high. The author describes the performance of these generators and makes a comparison between the air and hydrogen cooled-type