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In this paper are defined procedures for a flicker measurement according to standard IEC 61000-4-15 and the definition of a flicker is given. The software for measuring a flicker severity was developed and this software was implemented on concrete example. The developed software is based on digital signal processing. Input data is a certain file or data from the computer's RAM memory and the result is a value of the flicker severity. This concept allows that the developed software can be used both for the flicker measurements and for a simulation of flickers in the power network. A hardware support for the software can be any acquisition card which satisfies minimum conditions concerning the flicker measurement and a range of input signal. The aim of this work was to develop a universal application that can be used for the flicker measurement and also for the flicker analysis which can be made after simulations in the power network. In this paper is made a model of characteristic consumer which produces flickers in the power network. The conclusions in this paper relate to the procedures of development of a flickermeter and to the example that is analyzed in this work.Index Terms--power quality, flicker, flickermeter, flicker definition, testing flickermeter, example of flicker measurements, flicker simulation example.

In the concept of distribution generators (DG) integration, distribution network becomes active and philosophy of network guidance and control changes. The presence of DG in the network often results in the active losses increase and thus the maintenance costs raise. This problem is offen noted in radial networks, as DG in this type of networks make network doubly fed. This paper gives an answer how to run one or more small hydropower plants (SHPP) in a radial network with minimal losses. In this paper, the analysis of power flows, combined with optimization methods and technical constraints (voltage constraints according to EN50160) are carried out. One example with detailed calculations, conclusions and diagrams comments is conducted. The conclusions in this paper directly indicate the possible measures to be implemented in order to achieve a higher SHPP and distribution network performance.

In this paper is presented an approach in development of measurement system (MS) for analyzing the power quality (PQ). The main aim of this paper is to present procedures of PQ measurements according to the strictest norms and standards and to develop a system for measuring specific indicators of PQ. The developed MS is implemented on several examples. In this paper is presented an example of implementing the MS in analyzing the loads mode of an apartment with appliances of new generation (energyefficient appliances). In the paper is also explored the problem of implementation of universal acquisition cards for their application in analyzing PQ. The main focus of conclusions in this paper is comparison of present and future systems for monitoring the PQ. Index Terms--Power quality (PQ), acquisition card, measurement system (MS), measurement of harmonics, measurement of flickers

Power quality (PQ) is becoming important factor in proper functioning and operating of power systems (PS). Continuous PQ monitoring represents basics for efficient exploitation of power systems. Systems for continuous PQ monitoring and their networking with central system are major investments. This paper lists conditions for modeling of certain PS elements and describes concept of power network modeling in PQ analysis. First part of the paper gives mathematical formulation of the problem; second part describes high voltage transmission line in frequent domain using system of phase values, while the third part of the paper is an example in time domain modeled in EMTP-RV software package using system of phase values. Performance of power network in quasi-stationary state is analyzed and during the simulation five changes of voltage conditions occur as consequence of overloading. The PS is loaded with nonlinear loads generating high current and voltage harmonics. Voltage and current harmonic in the places of energy exchange are observed; furthermore estimation of voltage harmonics in the places with no PQ monitors is conducted. Conclusions of the paper indicate possible usage of presented algorithm for real time PQ analysis and for post PQ analysis. Index Terms--Power Quality (PQ), Voltage Harmonic Estimation (VHE), Power Systems (PS), High voltage line (HVL)