Ivan Skokljev

A new symbolic analysis approach to the DC load flow method

Abstract A new symbolic analysis approach is proposed to the DC load flow method. The power system network parameters are given by symbols and the system active line power flows are derived analytically as closed-form symbolic expressions. An original program SALF is presented as a universal tool to find the line powers by an automated computer-aided algorithm. The theory of the DC load flow method is reviewed. The approach is illustrated by standard network examples. The approach exposed is targeted at researchers and experts dealing with analysis, planning and operation of transmission power system networks.

Evolutionary Algorithm for Calculating Available Transfer Capability

Abstract The paper presents an evolutionary algorithm for calculating available transfer capability (ATC). ATC is a measure of the transfer capability remaining in the physical transmission network for further commercial activity over and above already committed uses. In this paper, MATLAB software is used to determine the ATC between any bus in deregulated power systems without violating system constraints such as thermal, voltage, and stability constraints. The algorithm is applied on IEEE 5 bus system and on IEEE 30 bus system.

Network switching model based on the upgraded Mamandur-Berg method

Abstract The paper presents the power injection switching model based on the Mamandur-Berg sensitivity method for branch (line or transformer) outage simulation. The Mamandur-Berg method is upgraded here to include all relevant network switching actions, such as switching-in, busbar coupling/splitting and branch ‘changeover’. The model is developed and presented in the paper. This model is afterwards used in security assessment for overload reduction. It comprises a set of heuristic rules which bounds the search for the solution. The algorithm makes full use of sparse-matrix programming. It is tested on an 82-node 127-branch network.

Optimal location and sizing of photovoltaic plant

Location and sizing of photovoltaic plant from the aspect of independent power market participant are studied. Of the two methods developed, the first one is based on the DC network model and the second one relies on full AC model of the network. Genetic algorithm with the twofold objective function is used. The first goal is to locate the network node with the maximum available transfer capability (ATC) under the bilateral transactions regime and the second, to maximize the sizing of the plant in that node. The two standard test systems, the IEEE 5-buses system and the IEEE 30-buses system, show the applicability of the method in the paper.

A Software Tool for Available Transfer Capability Teaching Purposes

This paper presents an educational software tool with a user-friendly interface, which can be used for evaluation of available transfer capability (ATC). The software was developed using the MATLAB1–2 software package. The software is designed for engineers who are involved in trading in electrical energy and for students (undergraduate and Masters) of Electrical Engineering who could, by using the software, gain a better insight into the theoretical knowledge and solve some practical engineering problems. ATC model limitations include the usual d.c. load flow inherent limitations as well as line thermal limits, prevalent in the literature on ATC. The structure and software capabilities are presented within the example of an ATC sensitivity study on a five node/seven line transmission network, used for zonal market activities tests.

Energy balances of South East European countries with the emphasis on the influences of renewable energy sources

This paper at its very beginning presents the realized electricity production by type of used primary energy sources, with the emphasis on the renewable sources, consumption and exchange of electricity over the past ten years for all of the countries of South Eastern Europe. After that, an analysis of the key energy aspects in the observed period is given. Further on, breakdown of renewable energy sources by type is given, and its development over the last decade is presented and analyzed. For the year 2015, production from renewable energy sources of several countries from the region, which are the biggest ones in the segment of electricity production, is presented in more detail. Short review of the relevant European legislation that covers this area is also presented, and is followed with the conclusion of how to treat renewable energy sources installment and production in the following years in order to successfully meet the so called 2020 targets.

Power network steady-state M-robust estimation and observability

The new and robust bad data suppression (BDS) type two-step state estimator based on the principle of M-estimation and the related observability questions are considered in the paper. The tests are conveyed on a standard test network example.