Development of a Renewable Energy Based DC Excitation System in a Micro Hydro Power Plant

MHPPs （micro hydro power plants） have become prominent in hydropower plants as a solution to provide the energy demands of the grid. In this study, a new hybrid renewable energy based DC excitation system for synchronous generator in the developed MHPP system is introduced. Proposed hybrid DC excitation system consists of solar ＆ hydrogen energy based power generating systems. Hybrid renewable energy based system is used for the excitation of the synchronous generator in the MHPP test system. The renewables are used as a secondary energy source to provide the excitation current to a synchronous generator that generates energy in MHPP. A PV （photovoltaic） array is used as the main source of excitation, and a FC （fuel cell） stack is used for DC excitation in the lack of sunshine. In the experimental setup, an electrical control card is developed, and a microcontroller is used to perform the proposed excitation system. All experimental results obtained from 5 kW rated power MHHP test system. Experimental results show that, the proposed method provides the continuous excitation current, and the operation of the synchronous generator is uninterrupted. The proposed method is also practical and easily implemented for MHPP systems.

New Analytical Model for Optimal Placement of Wind Turbines in Power Network under Pool and Reserve Markets Conditions

In this paper a new market based analytical model is proposed for optimal placement of Wind Turbines (WTs) in power systems. In addition to wind turbines, thermal units (THUs) and Pumped Storage Hydro Power Plants (PSHPPs) owners participate in power market. Objective function is defined as participants’ social welfare achieved from power pool and ancillary markets in yearly horizon. Wind turbines have been modeled by probability-generation tree scenarios based on statistical information. We concentrate on investment profits of WTs numbers and its generation capacity beside to PSHPPs and THUs power plants in power systems due to increase in high flexible tools for Independent system operator into the planning and operation planning time interval. For effectiveness evaluation of proposed model, simulation studies are applied on 14-Bus IEEE test power system.

Complex Use of the Water Spring Istog

While living in the century of crisis （of energy and water）, more focus should be given on renewable energy. Since Kosovo is more limited in hydro-energy resources than the neighboring countries, it is essential to study them and put to use more efficiently. Subject of this study is Istog spring as it is the most important spring of Mokra Gora together with Vrella and White Drino. The spring is analyzed as a complex resource on water economy providing： fish （trout）, potable water, water for irrigation and hydro-energy （currently not in function）. The focus of the study remains the hydro-energetic component, not just a revitalization process but as an upgrade of the existing facility to increase the capacity by 2-3 times. This study is based on information selection and processing regarding detailed technical and economic analysis providing a method for other springs that will be studied in the future. Two technical solutions to the problem are provided as the best economical and technical solution. Solution I has one level and a calculated flow of 7.5 m^3/s and consists generally of renovation works on existing facilities; Solution 2 plans the construction of another level 3 m lower than the existing one, increasing so both the hydro-power capacity and implementation cost for the project Both solutions provide little to no impact on the spring main attributes. The valley ecology will not be influenced because the water after HPP （Hydro Power Plant） will be flowing in its own bed. After this study, Istog spring will be more attractive to donors and will contribute in improvement of energetic structure in Kosovo that for the time being is poor in hydro component.