Dynamic Modeling and Control of Microturbine DG System for Autonomous Operation

Decentralized Generation (DG) is expected to play a vital role in the future of electric power system. The power electronics interfaced microturbine generation systems are currently attracting lot of attention to meet different needs both at end consumers and the distribution utility levels. Dynamic modelling of the microturbine is a challenging process because manufacturers do not readily provide model data, if any exist at all. In this paper a proposed microturbine DG dynamic model is developed in Matlab-Simulink and implemented using a test system built with SimpowerSystem block set. The proposed model is interfaced with the electrical system using a simplified Voltage Source Inverter (VSI) model. This model supports power system applications as long as harmonics are not the main concern. For many techno-economical reasons, the amount of DG systems is expected to increase rapidly, especially for rural electrification. Therefore, this paper investigates the autonomous operation of microturbine DG system with a Voltagefrequency (V-f) control strategy. Test and validation results of the proposed dynamic simulation model and the proposed inverter controller are presented. Analysis of results shows that the proposed microturbine DG model has the advantage of generalized structure so that it can be used for performance testing of different microturbine commercial types, and it could be used for simulation and study of different DG applications by establishing proper interfacing and controllers. Index Terms Decentralized Generation (DG), Microturbine Model, Voltage Source Inverter (VSI) Model, PID speed Controller, V-f control.