A tool for gas turbine dynamic simulation is presented in this work. First, a thermodynamic model of the engine is presented, capable of predicting engine performance at full and part load conditions. This model considers modern features as variable geometry compressor and air cooled turbine expansion. Then, two different control techniques are assessed in order to control the engine during transient operation. After analyzing the stability and robustness of both controllers, one of them is selected due to its faster response and better stability. The complete model is validated and then applied to two different transient conditions. First, some perturbations are applied in order to see how the control system is able to compensate these abnormal situations in order to maintain the frequency of the shaft. Then, a ramp up from idle to peak load is analyzed. This last study is aimed at assessing the stability of the model for the widest possible load range. According to the results shown, the stability and robustness of the model is satisfactory. (C) 2010 Elsevier Ltd. All rights reserved.