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Provides an abstract for each of the invited presentations and a brief professional biography of each presenter. The complete presentations were not made available for publication as part of the conference proceedings.
A hybrid model of the electrical power generation system that combines the computer model of the power scheme with the real control system is described. The results of research of the electromagnetic and electromechanical processes for main working regimes are presented.
Electrical networks, and physical systems in general, are known to satisfy a power balance equation which states that the rate of change of the energy in time equals the power at the port of the network minus the power dissipated. However, when complex power is considered, there does not seem to exist a similar statement for the imaginary power, either in the timedomain or in the frequency-domain...
One of the main issues related to the optimization of the MV (middle voltage) network is to reduce losses of active and reactive power. Lower losses of active and reactive power give not only economic advantage, but also improvement of energy quality. The object of regulation that can be used for these purposes are transformer with On-Load Tap Changer and capacitor's banks. This paper presents results...
Emergency power supply facilities and loads connected by long power cables are becoming increasingly common in industrial power systems. System facilities connection via a power cable introduces a considerably significant shunt capacitance to the source power system, giving rise to low natural or resonant frequency. One source of harmonic currents is the system transformer. When initially energized,...
Interturn faults (ITFs) in power transformers is the major cause of transformer failures. If this fault is not quickly detected, it can be extended and led to catastrophic failure and a complete transformer breakdown. This can generate high costs for repair or replacement and financial loss due to the power outage. The objective of this paper is detection of low severities ITF under unbalanced load,...
Electrical equipment like motion detectors, time switches, presence sensors, timers, low power LED lamps or LED night lights have real power less than 1 Watt at the AC grid 230V/50Hz. But if we analyze the circuit topology, there are many conventional resistors to limit the inrush current. With an inrush controller with switched transistor we can eliminate the resistors and improve the efficiency.
Recent work completed by CIGRE/CIRED Joint Working Groups C4.108 and C4.111 has pointed to the general conclusion that there is a poor correlation between measured voltage fluctuation levels (“flicker”) and complaints from network customers. Voltage fluctuation measurement procedures have long been standardized in the IEC flickermeter (IEC Standard 61000-4-15) and historically the correlation between...
Vehicle electrification has become an important measure for greenhouse gas reduction in many countries worldwide. Regardless of what type of electric vehicles (EVs), the on-board battery must be charged via a charger or charging station. In the future, when large numbers of EV chargers or charging stations are connected to distribution systems, there will be a degree of influence on the system operation...
The main source of voltage signals used for distance relays are capacitive voltage transformers (CVTs). During line faults CVTs generate transients that influence voltage signals. During the transient period it is difficult to distinguish if the fault occurred within the operating zone or outside the protected line, which might lead to a maloperation and in the worst case, a system blackout. In this...
Traditionally, Extra High Voltage (EHV) transmission systems consist exclusively of Overhead lines (OHL) but in the recent years the utilization of High Voltage AC (HVAC) power cables is increasing due to environmental, political and operational aspects. For transmission networks consisting of purely OHLs there are proposed guidelines concerning the modeling depth needed for acquiring accurate results...
Energy generation evolves quickly towards a significant share of renewable sources, with increased challenges regarding the system stability and provision of ancillary services, including the non-mandatory voltage control (NMVC) by generators. Under these circumstances, accurate measurement solutions are required to support competition and increase the quality of such services. Current measurement...
The article presents the problem of harmonic source detection (currents and voltages) in electric power networks. In practice, this problem comes down to determining the extent of the participation (of harmonic sources) between two parts of the point of common coupling (PCC) in network. There are many ways to solve this problem, but unfortunately there is no substantial certainty regarding the validity...
Among the strategies of protecting information assets of the power system, sharing of information about current cybersecurity incidents between energy operators appears to be a prerequisite. Exchange of information leads to the effective detection of attacks and exploited vulnerabilities as well as the identification of countermeasures. This paper presents the results of continuation of our works...
The paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The...
The contact resistance is the key variable that characterizes the stable performance and long-term service of an electrical connection. It is worth noting that the contact resistance in substation connectors can be several times that of the connector's resistance. To reduce connection losses and thus decrease connector's operating temperature, it is important to minimize contact resistance. The aim...
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