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PAPIČ, I.
»SMART GRIDS DEVELOPMENT PROGRAM IN SLOVENIA«
KOMUNALNA ENERGETIKA / POWER ENGINERING, 2
The concept of Smart Grids builds upon the modern concept of operation and power system planning. By joining classical (large centralized generation units, a transmission and distribution network) and new elements (distributed generation, advanced metering infrastructure, demand side management, virtual power plants, electric vehicles and energy storage systems), SmartGrids creates an effective system.
KOLENC, M., PAPIČ, I., BLAŽIČ, B.
LOCAL VOLTAGE CONTROL IN SMART GRIDS WITH TIME DEPENDENT POWER FACTOR
KOMUNALNA ENERGETIKA / POWER ENGINERING, 14
This paper deals with the influence of a lagre share of dispersed generation (DG) on a voltage profile in distribution networks. Until recently, the newly installed DG operated only with constant power factor, which was usually cos = 1. Countries around the world are now accepting the new rules and guidelines, which require that all DG participate in the voltage regulation, as they are the main reason for the voltage rise in distribution networks. Slovenia has already issued a document that prescribes different static characteristics Q(U), which determine the power factor of DG with respect to the voltage at the connection point.
As the new technologies nowadays allow bidirectional data flow in almost real time, more active participation of generators in voltage regulation is possible. Concept of voltage regulation which exploits these ideas is presented. At a certain intervals desired cos can be send to all generators in the network. Advantages of such a regulation are pinpointed out. Different solutions were evaluated by means of simulation on a real medium-voltage network, which demonstrate good flexibility when using such a methods.
HERMAN, L., PAPIČ, I.
OPTIMAL REACTIVE POWER CONTROL IN INDUSTRIAL NETWORKS WITH DISTORTED VOLTAGES AND CURRENTS
KOMUNALNA ENERGETIKA / POWER ENGINERING, 15
In modern industrial processes, the number of nonlinear loads, which are known to be a major source of current harmonics, is constantly growing. At the same time, the number of reactive power compensators operating in these networks is also growing. Although compensators are not sources of harmonic distortions, they may cause high amplifications of harmonics by creating resonance conditions. This can cause malfunctions or even loss of equipment. Due to the growing number of reactive power compensators in a typical industrial network, the control of these networks is also becoming increasingly demanding. An industrial network operator has a difficult task of finding an optimal configuration of compensators, which covers reactive power demands and at the same time does not cause resonance amplifications of harmonics. Thus, in this paper, a concept of a virtual compensator is proposed. It combines all reactive power devices of a certain network within a single control scheme. This gives the operator the ability to control each compensator independently in real time and to achieve optimal configuration of compensators, for every operation point of the network. The effectiveness of the proposed algorithm is demonstrated on the realistic industrial network model by means of simulation.
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