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 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.

Most power systems in underdeveloped and developing countries are based on conventional power plants, mainly "slow-response" thermal power plants and a certain number of hydro power plants; characterized by inflexible generating portfolios and traditionally designed to meet own electricity needs. Taking into account operational capabilities of conventional power systems, their development planning will face problems with integration of notable amounts of installed capacities in wind power plants (WPP). This is what highlights the purpose of this work and in that sense, here, possible variations of simulated output power from WPP in the 10 minute and hourly time interval, which need to be balanced, are investigated, presented and discussed. Comparative calculations for the amount of installed power in WPP that can be integrated into a certain power system, according to available secondary balancing power amounts, in case of concentrated and dispersed future WPP are given. The stated has been done using a part of the power system of Bosnia and Herzegovina. In the considered example, by planned geographically distributed WPP construction, even up to cca. 74% more in installed power of WPP can be integrated into the power system than in case of geographically concentrated WPP construction, for the same available amount of (secondary) balancing power. These calculations have shown a significant benefit of planned, geographically distributed WPP construction, as an important recommendation for the development planning of conventional power systems, with limited balancing options.