Andreas Laskaris, "Software development for transient stability analysis of power electric systems with large wind penetration", Diploma Work, School of Electrical and Computer Engineering, Technical University of Crete, Chania, Greece, 2021
https://doi.org/10.26233/heallink.tuc.91014
This thesis concerns the implementation of software for the transient stability analysis of power electric systems with high wind penetration. The first chapter is an introduction to the traditional power grid with a reference to conventional generating units. It is then expanded to wind turbine units with a historical background in their use. In addition, a statistical analysis is placed that highlights the importance of these units. The second chapter analyzes the distribution of wind speed, emphasizing its contemplative nature. What refers next is the way of calculating the wind distribution with the Weibull method. Finally, the analysis ends with the basic principles of the theory of flotation where the power given by the wind on the blades of a wind turbine is calculated with good accuracy. In the third chapter the theory of the operation of electric motors is developed with great emphasis on modern generators where all the features and differentiations of modern motors are distinguished. The analysis extends to the use of the Park transform, which extends to solving the equations of synchronous electrical excitation generators and permanent magnet, respectively. After the solution of the two types of synchronous generators, the Stability of synchronous machines in electricity systems is analyzed. Finally, the results of the simulation of a synchronous electrically excited generator under its operation as a conventional production unit are presented. The fourth chapter introduces the general structure of a wind turbine with the basic technical characteristics of its systems. Then the individual systems are separated with the first of them analyzing the aerodynamic system and the theory of maximum power point tracking from the wind. After an additional analysis of modern generators in wind systems, the continuation concerns the electronic converters that are installed and how to control them. At the end of the chapter, the response of a wind system is simulated in normal conditions, in sinking voltages, gusts of wind and short circuits. The fifth chapter deals with the description of an electrical network and the power flow analysis in it. The form of each component of the network is mentioned separately along with the way of resolving the power flow in each one of them. Meaning that this chapter deals with the general form of scales and their voltage calculations using power flow equations. In the sixth and last chapter, the previous chapters are combined in order to implement a software that calculates the transient stability of the production units of a network when extreme conditions are applied to it (wind gusts, sharp increase in power demand, short circuits, etc.). The characteristics of the software components are listed at the beginning. Then the method of calculating the load flow on a given electrical network is analyzed. At this point, the calculation method Gauss with the Gauss-Seidel extension are described. Next to it, there is a good analysis of the differential equation solving method that applied to every chapter of this thesis. At the end of this chapter there is a simulation of how each system reacts to various extreme conditions like the ones described before but with the extention that all systems are connected to a theoretical grid so that each system can affect the other. Finally, the final conclusions and possible future extensions for this software are presented.