Effect of Different Distributed Generation Technologies on the Performance of the Electrical Distribution Networks

Abstract

The penetration of renewable energy resources in power system as distribution generations (DGs) is increasing due to the continuous increase in the electric energy demand and the fluctuation of fossil fuel prices which makes many economic challenges including shortages in the electricity and water resources. To overcome these challenges, the Egyptian government is paying tremendous efforts to increase the investments in oil and gas sectors while seeking diversity in Egypt’s non-conventional sources of energy. Moreover, Non-conventional sources of energy are better than the conventional sources from the economical side and the environmental point of view, since they have a minimum environmental impact, higher efficiency, better performance and low cost. One of the most important non-conventional sources of energy is the geothermal energy which is considered a clean, fuel free and renewable energy that is used worldwide in generating electrical energy without a need to burn fuel. A controlled electrical and mechanical design of a dynamic geothermal power plant model for low temperature geothermal plant is presented in this thesis using Simulink model and MATLAB software. The presented model represents the whole power plant starting from the geothermal temperature of the production well ending with the electrical power output from the used synchronous generator and the output variation with the different geothermal temperatures. The model includes all the mechanical equations and energy conversion equations related to the organic Rankine cycle, enthalpy curves and the organic fluid used in the mechanical part of the plant. On the other hand, it shows the effect of variation in geothermal temperatures on the generated electrical power. The model shows clearly the variation and unstable response of the electrical power output energy signals at different geothermal temperatures as. A PI controller based on Genetic Algorithm is used to control the steam governor of the turbine to overcome variation and unstable electrical power output at different temperatures so as to be integrated as a generation unit in a power system. The geothermal generation unit is used as a DG unit integrated to IEEE 33 Bus system. The IEEE 33 bus system’s electrical performance is studied before and after adding geothermal DG unit from the point of view of the system power losses and the voltage profile. An optimization tool in the MATLAB Genetic Algorithm is used to obtain the optimum number, size and location of the geothermal DG unit integrated in the IEEE 33 bus system to enhance the voltage profile and decrease the power losses of the system with objective function of least power losses and enhanced voltage profile. A clear comparison is displayed using the voltage profile with and without the DG unit shows the great improvement in the voltage profile and power quality after adding geothermal DG unit.