Harmonic voltages are important voltage quality parameters defined in EN 50160. For harmonic voltage studies in electricity networks, harmonic emission of loads is often modelled as harmonic current source. In this paper harmonic current sources were parameterised on the basis of measure-ments of total harmonic current emission of several different low voltage networks. Measurements from low voltage net-works with different typical customer configurations were used: residential, offices and PV. A real medium voltage electricity distribution network of an Austrian distribution system operator, with significant consumption of residential and office customers, was chosen for this analysis. In order to automate the harmonic load flow calculations in DIgSILENT PowerFactory for every 10-minute interval of one week, a script in DIgSILENT Programming Language - DPL was developed. Harmonic voltage results from the harmonic load flow simulation are compared with the results of harmonic voltage measurements from power quality monitoring system installed in this network. The goal of this paper is to assess the suitability of the approach, where only background harmonics and key harmonic current sources are modelled. Since the approach provided good results, it can be used in future work as a basis for optimising the number and locations of power quality monitors in electricity distribution networks.

In every power system there are consumer areas away from traditional power networks. Existing grid expansion

Power quality is one of the important challenges for the smart distribution grids. It is not possible to know the state of power quality in the network without appropriate measurements or monitoring. As an answer to need for power quality monitoring in smart distribution grids, this paper further develops the Integrated Power Quality Monitoring System (IPQMS). IPQMS integrates power quality data from all the measurement devices available in the smart distribution grids: power quality monitors, portable power quality analyzers, smart meters, protection relays, fault locators etc. Smart meters are the key sensors in smart distribution grids and should be used as indicators of power quality disturbances in IPQMS. The complementary use of power quality monitors and smart meters in IPQMS should enable the analysis of the propagation of power quality disturbances throughout the distribution network. Current state-of-the-art smart meters have certain capabilities regarding the monitoring of some power quality parameters. The necessary upgrades to the state-of-the-art smart meters regarding their power quality monitoring capabilities are discussed in this paper in the context of their role in IPQMS. This paper elaborates in detail one new concept of operation and process algorithms for IPQMS, with special emphasis on smart meters. This paper also presents experimental results of integrated power quality monitoring using power quality monitors, state-of-the-art smart meters and protection relays. The presented experimental results prove that with integrated power quality monitoring, distribution system operators can get a complete information about power quality in their networks.

Expected increase in plug-in electric vehicle (PEV) sales makes different analysis of their impacts on electricity distribution networks very interesting. This paper analyses the impacts of PEV charging on an example of a real low voltage (LV) distribution network for various PEV penetration scenarios (5 %, 10 %, 20 % and 50 %). Two main charging technologies were modelled: slow charging at private charging stations and fast charging at public charging stations. Two basic charging modes were analysed: unregulated and regulated. The analysis was done in a professional software tool for analysis of LV distribution networks: WINDis. The results have shown that PEV charging can have negative impacts in terms of increased peak load, increase of power losses, overload of transformers and lines, decrease of voltage values and increased voltage asymmetry. It has been shown that the LV network can support regulated slow charging of a large number of PEV's.

— Accurate forecast of electricity consumption is important for every electric power company because it determines the dynamics and characteristics of future construction of power facilities. Speaking in the long term, if the forecasts were too low or high, it could cause a number of adverse events leading electricity companies in the generation deficit or complex financial problems due to excessive investment in generating facilities that are not fully utilized. This paper presents the results of the forecast energy demand, electricity and active power of Bosnia and Herzegovina (B&H) system, using the Model for Analysis of Energy Demand (MAED) methodology. Modelling of base year is done on the basis of available statistical data and trends in individual sectors upon trends in other European countries. Results were compared with forecasts that were prepared by other methods in other time periods

—In terms of power sector restructuring and electricity market opening there have been significant changes in the functioning of activities at the level of Public Enterprise Elektroprivreda BiH d.d - Sarajevo (EPBiH). Distribution activity in an open electricity market is not a market activity, but the regulated activity, and although does not participate directly in the electricity market, its action must allow unhindered development and functioning of the market in which suppliers competes. The introduction of the smart grid concept in electricity distribution activity is a particularly challenging area of research due to the actuality and importance. The paper presents the elements of the business framework of EPBiH in terms of application of modern technologies in the area of smart grid and the changes that inevitably occur during transition process of energy sector in general

Anticipated mass production and integration of plug-in electric vehicles (PEV) in the power system asks for the analysis of the impacts of PEV charging on different aspects of power system operation. This paper presents the analysis of the impacts of PEV charging on the example of a part of a real medium voltage distribution network from the Bosnia and Herzegovina. Three different charging technologies were modelled: slow charging at private charging stations, fast charging at public charging stations and ultrafast charging at DC charging stations. Three charging modes were analysed for slow charging: unregulated, regulated and regulated with Vehicle-to-grid (V2G) intervals. The analysis showed that the charging of PEV's has negative impacts on the distribution network in terms of the increase of peak load, the increase of energy losses, the negative impact on voltage profiles and the overload of distribution transformers. By regulating the process of PEV charging most of the negative impacts can however be reduced.

In many countries, renewable energy technologies receive increasing attention. Several countries have set ambitious targets for integrating renewable energy sources into their power systems. A special place occupy wind power plants (WPP) and photovoltaic power plants (PVPP), characterized by variable output power in relatively short time intervals. These variations represent a challenge for managing and development planning of certain power systems. Appropriate measures in reduction of output power variation ranges can be achieved by geographical dispersion of these generating units. In this paper, quantitative effect analyses of geographical dispersion on requirements for balancing power has been done. Simulations and calculations have been performed using real, measured data on wind and solar energy potential. The research includes WPP and PVPP and has been extended to certain hybrid power system (HPS) configurations. Comparative analyses of integrating significant power in the considered generating facilities at one location and its wider spatial distribution showed significant decrease in balancing power requirements for even more than 60% in the case of geographical dispersion. Calculations carried out pointed also to a certain complementarity between WPP and PVPP in HPS configurations.

The issue of backup for intermittent renewable sources comes with the relatively low capacity value and the very limited contribution to generation security that such sources have. However, beside standard compensation measures (power system flexibility, positive and negative reserve, etc.), inherent natural properties of wind and solar power resources can play a certain role as well. This work builds upon previous analyses and gives a quantitative system non-specific data assessment of individual power generation scenarios (dispersed power generation, hybrid solar-wind power generation, etc.), based on one year data records available for three sites of Bosnia-Herzegovina. The scope of this work is to statistically evaluate and compare the contribution of each case scenario to the required power system backup margin and the associated capacity value for the selected resource. It has thereby been found that for the given data dispersed wind generation exceeds the effects of a hybrid wind-solar scenario, however, positive effects were found to come with a mixed dispersed wind-solar power generation as well. The capacity value assessment resulted in improved properties of the output reliability, but only up to a limited capacity factor of the wind only scenario.

Size and complexity of power systems impose significant challenges for the power system analysis and control. As the power system becomes more complex there is a great need to develop improved and sophisticated tools for power system analysis and simulation. These tools should be able to accurately replicate real events that occur in electric power network and help to understand dynamics of changes. A number of software packages have been developed for power system research, analysis, planning, designing and teaching. This paper describes how to utilize an electric Power System Analyzer (PSA) as a useful instrument for power flow studies. The analyzer is designed to be user-friendly, easy-to-use, with the ability to optimize power flow and to visualize the effects of changing problem parameters. PSA can handle power system networks up to 100.000 nodes.

In this paper, the complementary nature of wind and solar energy has been considered, especially by analyzing output power variations from a photovoltaic power plant (PVPP), a wind power plant (WPP) and their combination in a hybrid system. For these purposes, an own model has been made, with calculations based on real wind and solar energy potential data. Two hybrid system configurations have been observed; the first where both generating facilities have equal installed capacities (i.e. 2 MW each) and the second where the installed capacity of the WPP is five times larger. Effects of implementing these hybrid power systems have been verified by carrying out a simulation study using a practical load demand profile, with a recorded maximum hourly value of 3.5 MW. The complementary nature is more expressed in the first hybrid system configuration, where a decrease in the output power variations from the hybrid system considered as a whole in comparison with variations when considering generating facilities individually, has been observed. But, this hybrid system configuration manages to meet hourly consumption in only 7.06% of time. The complementary effect is reduced in the second hybrid system configuration, and output power variations have been observed in a very wide range. However, this system manages to meet hourly consumer needs in 41% of the time. Neither one of the two cases can independently satisfy observed demand on hourly basis. Acknowledging the fact that in the second case there are periods of time when the generated electricity is up to 3.5 times higher than the hourly consumption, as well as the positive difference between generation and consumption on annual basis, an off grid system would be feasible with proper storage facilities.

In distribution system, the subject of fault location has been of considerable interest for a long time. The objective of this paper is to develop Cumulative approach for fault location based on statuses of Fault Indicators (FI), Circuit Breakers (CB), Fuses and Fault Impedances from distance protection devices. This approach is using mainly graph theory algorithms and Area Marking Strategy to resolve fault diagnosis problem in electric power networks. Unlike neighborhood approach where one link only affects the marking of neighbor areas, cumulative approach marks all areas down the link. In many situations, cumulative approach may outperform neighbor approach.

This paper describes the extended algorithm for Voltage VAr control (VVC) which takes into account operational costs, flexible loads, batteries and demand management in smart grid solution. This algorithm shows how commercial and electrical conditions are taken into consideration and discusses related optimization issues. The practical aspects of optimization using VVC in decentralized environment of smart distribution grid are discussed.