MODELING OF DISTRIBUTED GENERATION SYSTEMS

Abstract

Consumers want an economical and uninterrupted electric power. It is crucial to the industrial consumers and wholesalers who have to pay the penalty for a blackout, if power is disconnected for any reason. Recently, distributed generation (DG) has become an attractive method of providing electricity to consumers and retailers. In addition, from the viewpoint of economic feasibility, the costs of installing the generators and producing the electricity can be comparatively inexpensive using the DG method. Furthermore, electrical or thermal efficiency can also be improved if the utilities use co-generation or a combined heat cycle. In this thesis, dynamic models of small turbine generators [i.e. a Microturbine (combustion turbine), a Diesel engine], are used for analysis of their performance. Also, the detailed permanent magnet synchronous machine model is developed. Study of self-excited induction generator, salient-pole synchronous machine and the excitation system are obtained for the standard simulation. The simulation will be performed with an isolated load system. The machines are connected with a local load in order to develop the terminal voltage. The goal of this thesis is to evaluate the performance microturbine and diesel engine energy systems through computer simulation studies. The primary focus of this study•is the development of dynamic models for a standalone microturbine generation system and a diesel engine generation system. The system models developed is suitable in distributed generation studies. A dynamic model for the microturbine generation system is achieved by integrating models of a mieroturbine and an electric generator driven by it. The model illustrates the dynamics of the microturbine and its control systems. A set of mathematical equations are used to model a permanent magnet synchronous machine acting as the electric generator of the microturbine generation system and study of self-excited asynchronous (induction) generator with microturbine generation system. The developed system is capable of simulating the dynamics of the microturbine generation system, demonstrating its ability to meet load requirements. The dynamic model of the microturbine generation system is integrated using power electronics interfacing and model of diesel engine generation system are iii simulated in MATLAB/Simulink. Simulation results indicate the suitability of the developed model to study the dynamic behavior of the generation systems under different load conditions. Keywords: Distributed generation, Microturbine, Diesel engine.