Martin Kanálik

The effect of negative active power consumption of asymmetrical and variable load represented by EAF

This paper deals with the short-term active power consumption of electric arc furnace (EAF) as an example of variable and asymmetrical three-phase load. The aim of this paper is to describe the phenomenon of negative active power consumption effect in some phase of three-phase power system in case of asymmetrical and variable load in real condition. The theoretical example of the negative power consumption in special case is also presented in this paper. The results of two sets of active and reactive power measurements during one duty cycle of the small EAF is also presented in this paper.

Measuring of real value of short-circuit power in island operation condition

This paper deals with the problematic of the actual short-circuit power determination in real conditions. Presented principle of a real value of short-circuit power determination in arbitrary node of the power system is based on the measurement of one cycle RMS voltage and current changes. Described should be useful for determination of short-circuit power in the nodes electrically far enough from any synchronous machines (mainly from a generators of big power plants), in which the subtransient and transient effects of synchronous machines can be neglected. The comparison of the maximum short-circuit power computed according to the IEC 60909-0 standard and the actual short-circuit power obtained from the measurement of RMS voltage and current changes in the island operation of a small network is presented in this paper.

Increasing Net Transfer Capacity (NTC) by UPFC in Central East Europe power system

Most important issue in electricity markets is the maximizing of Net Transfer Capacity (NTC). This paper presents an approach for the placement of one Unified Power Flow Controller (UPFC) in interconnected power systems to increase NTC. Detailed analysis is presented for Slovak - Czech and Slovak - Hungary interconnection in Central East Europe network. Simulation results with and without UPFC are used to analysis the impacts of UPFC on the NTC between Slovakia - Czech Republic and Slovakia - Hungary.

UPFC influence to transient stability of power system

Large-scale power systems operation is faced with many challenges. One of many criteria, which should be fulfilled are stability criteria. Interconnecting separated power systems into interconnected network results in large system complexity, and therefore mixed influences from one power system to another part. Also, new devices are introduced to improve power system performance, like FACTS devices. Main goal of this paper is to examine influence of one of these devices to power system stability.