The use of renewable energy sources increases the energy self-sustainability of cities, enabling citizens to reduce energy costs, which results in an increase in their standard of living. However, solar energy penetration in Bosnia and Herzegovina, and its capital Sarajevo, is not in line with the possibilities. Furthermore, the Sarajevo Canton is extremely polluted during the winter months because of the use of unacceptable heating fuel. The aim of this paper is to introduce photovoltaic power systems use in heating electrification system. In this paper AQI is calculated based on historical data and the hybrid model EMD-SARIMA for air pollution and a solar production forecast is presented. The methodology was tested in the Sarajevo Canton, taking into account 35,000 households. In order to ensure clean air, renewable electric energy use for household heating should be implemented. The widespread use of inefficient individual heating systems characterized by inefficient and expensive use of firewood and the use of coal in individual furnaces in populated areas are the main problems of internal and urban air pollution in Sarajevo Canton. In order to reduce energy poverty in Sarajevo Canton, the use of a floating photovoltaic power plant located on Lake Jablanica with a capacity of 30 MW and the solar prosumers with capacity of 115 MW to provide the 196 GWh necessary for heating electrification of 35,000 households is implemented in this paper. Finally, based on correlation between AQI forecast and solar production it was calculated that the values of the AQI, considering the application of solar energy during 150 days (five months) in one heating season, have significantly decreased. Also renewable energy sources have a very important role in reducing carbon dioxide (CO2) emissions into the atmosphere and reducing urban pollution. With this approach, households would be heated by renewable electricity, which would make Sarajevo a cleaner, smarter city.

Abstract The paper consists of three parts. In the introduction and the first part of this paper are given basic theoretical considerations on possible ways for treatment of the neutral point in distribution grids with special reference to the method of neutral grounding of distribution transformers through a low ohmic resistor and a compensation coil. The second part gives the use analysis of a low ohmic resistor and a compensation coil as the future choice of neutral point grounding on the particular distribution grid powered by a substation TS 35/10 kV. In the third part of the paper, the results were obtained using an adequate dynamic distribution model, using the EMTP-ATP software package. Also, in this part, calculations are made for neutral grounding through a low ohmic resistor, a compensation coil, as well as in the case of isolated grids, and a comparison of the obtained values of the overvoltage coefficients.

Abstract This paper introduces and compares the various techniques for identification and analysis of low frequency oscillations in a power system. Inter-area electromechanical oscillations are the focus of this paper. After multiresolution decomposition of characteristic signals, physical characteristics of system oscillations in signal components are identified and presented using the Fourier transform, Prony’s method, Matrix Pencil Analysis Method, S-transform, Global Wavelet Spectrum and Hilbert Huang transform (Hilbert Marginal Spectrum) in time-frequency domain representation. The analyses were performed on real frequency signals obtained from FNET/GridEye system during the earthquake that triggered the shutdown of the North Anna Nuclear Generating Station in the east coast of the United States. In addition, according to the obtained results the proposed methods have proven to be reliable for identification of the model parameters of low-frequency oscillation in power systems. The relevant analyses are carried out in MATLAB coding environment.

Infrastructure of a distribution systems is facing major challenges with deregulated power system. Reactive power compensation can reduce energy losses in system, improve voltage profile and release feeder capacity. Installation of capacitors in distribution network is ensuring more efficient systems, but also provides economic benefit to utility and users. Vital task for capacitor implementation is to determine the best locations and size of capacitors. Hence, capacitor placement has an important role in distribution system planning. In this paper, using the professional software tool DigSILENT Power Factory, optimal capacitor placement is analysed in real low voltage distribution network. Results and analysis show that by optimal capacitor placement annual losses and adequate size for installed capacitors can be calculated. The capacitor placement problem consists of objective function which is composed of power losses and capacitor installation costs subject to bus voltage constraints. Optimization placement calculation is compared to installation of four capacitors in given case study distribution grid. Simulation results show that with appropriate software techniques optimal capacitor placement can be achieved in distribution grid.