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SREĆKOVIĆ, N., TRBUŠIČ, M., BELIČ, E., ŠTUMBERGER, G.
PROVIDING THE PROPER VOLTAGE PROFILES WITHIN THE MEDIUM VOLTAGE DISTRIBUTION NETWORK WITH PV SYSTEMS
KOMUNALNA ENERGETIKA / POWER ENGINERING, 32
Proliferation of the distributed electric power generation (DG) units requires the evaluation of different effects that DG units may have on the electricity network operation. Photovoltaic (PV) systems that are properly placed and sized, as well as equipped with the suitable control systems, may have positive impact on the voltage profiles and the reduction of losses of electric energy within the network. This paper discusses the possibility of providing the proper voltage profiles within the medium voltage distribution network, using the optimal reactive power generation and/or optimal reduction of active power generation from PV systems. Time – discrete calculation of the network operating conditions throughout the year were performed on two existing medium voltage distribution networks. Optimal values of reactive power generation and the reduction of active power generation were determined using the differential evolution in time points, where voltage rise, higher than the allowed, occurred. The results obtained suggest that reactive power generation from the existing PV systems should be used in voltage control, followed by the reduction of active power generation when necessary.
SREĆKOVIĆ, N., ŠTUMBERGER, G.
INFLUENCE OF ADDITIONAL PHOTOVOLTAIC UNITS ON ENERGY SAVINGS IN THE PART OF THE MIDDLE-VOLTAGE NETWORK IN MARIBOR
KOMUNALNA ENERGETIKA / POWER ENGINERING, 31
With higher penetration of distributed generation units in the distribution network, it has become important to evaluate their influence on network operating conditions. The paper analyzes the influence of active and reactive power generation of additional photovoltaic (PV) units in the part of the middle-voltage network in Maribor. Based on assessment of buildings’ roof PV potential, the most suitable roofs for PV system installation and their influence on yearly energy savings have been determined. The results show the energy savings achieved, due to the power loss reduction, obtained by the additional PV unit installation. Furthermore, energy savings achieved through proper reactive power generation are evaluated as well.
SREĆKOVIĆ, N., BELIČ, E., ŠTUMBERGER, G.
COMPARISON OF METHODS FOR LOAD FLOW CALCULATION IN LOW VOLTAGE DISTRIBUTION NETWORK WITH CONNECTED DISPERSED PRODUCTION
KOMUNALNA ENERGETIKA / POWER ENGINERING, 8
Load flow analysis represents one of the core methods used in modern distribution system operation. Therefore, it is necessary to provide efficient, numerically robust load flow algorithms with fast convergence and minimum usage of memory, suitable for variety of operating scenarios. The paper presents, compares and evaluates two efficient methods for load flow calculation in distribution network – backward/forward sweep method and direct method. The procedure of modeling the distribution network elements – line sections, loads, distributed generation units, as well as the implementation of algorithms, has been presented. The analysis has been performed on low voltage distribution network system.
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