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BELIČ, E., VOH, J., SUKIČ, P., ŠTUMBERGER, G.
IMPACT OF PHOTOVOLTAIC SYSTEMS’ REACTIVE POWER GENERATION ON ACTIVE POWER GENERATION AND TRANSMISSION LOSSES IN
THE LOW VOLTAGE DISTRIBUTION NETWORK
KOMUNALNA ENERGETIKA / POWER ENGINERING, 33
This paper evaluates the impact of photovoltaic systems’ reactive power generation on active power generation and transmission losses in the low voltage distribution network. The introduced experimental system consists of two major parts. The photovoltaic system represents the first part, in which every photovoltaic module is connected to the low voltage network by the individual microinverter. Two way communication is established to each microinverter by the communication gateway. The second part consists of a control system with data acquisition system. The flexible experimental system offers a possibility to add and establish different network connections of the single-phase or three-phase smart grids. Within the scope of this work, additional cable was installed to establish one phase low voltage network with the photovoltaic system on one side and network on the other. The results of the analysis and measurements performed for operation of experimental low voltage network show that the reactive power generation in photovoltaic systems increases the amount of active power that can be generated in photovoltaic systems without to violate voltage profile. However, with both of these actions transmission losses in the low voltage network increase.
VORŠIČ, J., VOH, J.
POWER SYSTEMS PROBABILITY CALCULATIONS SOFTWARE DEVELOPMENT
KOMUNALNA ENERGETIKA / POWER ENGINERING, 22
Method for planning and operation of power system which considers changes of operational conditions is described in this work. Input parameters - node loads in the load flow probability calculation are passed as probability function resulting from former operation careful analysis.
Based on described method calculation software has been developed. Node voltages, load flows, element currents and losses are calculated from node loads random vector considering connectedness among working and reactive power of same and adjoining nodes. Results (node voltages, load flows, currents and losses) are shown with expected value (arithmetical mean value) and mean square deviation in tabulated form. At the same time elements (lines, transformers) load control according to the natural (lines) and thermic power has been performed. Load flow histograms are real value of this method.
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