Performance Modeling of a Modern Gas Turbine for Dispatch Optimization

As electricity demand from individual power plants is expected to fluctuate increasingly due to the growing share of renewables, operators of large Combined Cycle Gas Turbine power plants will have to deal with increasing load variations and rapid load changes. To keep up reliability and availability of the plants, it is useful to accurately keep track of plant performance by comparing actual cycle data with a steady state base case model. This paper presents various aspects of the performance modeling of Alstom’s GT26 gas turbine as recently installed in the Netherlands. The modeling environment is GSP, a component based zero-dimensional software tool. Firstly, the modeling strategy is presented, taking into account the specific features of this sequential combustion gas turbine. Secondly, the method of processing field measurements to model inputs is shown and furthermore, the influence of measurement uncertainty on model parameter estimation is assessed. Procedures will be proposed to use this model in daily operation, to keep track of actual component loading. Later on, the recorded performance data can be used to evaluate maintenance as a function of actual operational history, as a basis for future strategies.