T. Szczegielniak

NUMERICAL METHOD OF COMPUTING IMPEDANCES IN SHIELDED AND UNSHIELDED THREE-PHASE RECTANGULAR BUSBAR SYSTEMS

In this paper, a new numerical method of calculating rectangular busbar impedance is proposed. This method is based on integral equation method and partial inductance theory. In particular, impedances of shielded and unshielded three-phase systems with rectangular phase and neutral busbars, conductive enclosure, and use of the method are described. Results for resistances and reactances for these systems of multiple rectangular conductors have been obtained, and skin and proximity efiects have also been taken into consideration. The impact of the enclosure on impedances is also presented. Finally, two applications to three-phase shielded and unshielded systems busbars are described. The validation of the proposed method is carried out through FEM and laboratory measurements, and a reasonable level of accuracy is demonstrated.

The effect of busbar shape and arrangement on currents and power losses in 3-phase busducts with two busbars per phase

Several 3-phase busducts with two rectangular busbars per phase arranged in various ways were analyzed with respect to unequal current distribution and power losses. The effect of busbar shape was analyzed. Unshielded as well three types of shielded busducts were considered. The analysis results could be helpful in busduct design. Streszczenie. Przeanalizowano kilka trójfazowych torów prądowych z dwoma prostokątnymi szynoprzewodami na fazę pod kątem rozdziału prądów między szynoprzewody oraz strat mocy w nich. Badano wpływ kształtu i ułożenia szynoprzewodów Rozpatrywano tory nieekranowane, jak i trzy rodzaje ekranowania. Wyniki analizy mogą być pomocne w projektowaniu torów prądowych. (Wpływ kształtu i ułożenia szynoprzewodów na prądy i straty mocy w trójfazowych torach prądowych z dwoma szynoprzewodami na fazę)

Distribution of temperature in the extensive plate

This paper presents an analytical computation method for determining the temperature distributions in the extensive plate. The mathematical model takes into account the skin effect. Results for various frequencies were shown and discussed.

The current density distribution in the three-phase bus-bars system

This paper presents an analytical computation method for determining the current distributions in high-current unshielded three-phase busducts of rectangular busbar. This method consists of using an exact formula of self and mutual inductance.

Magnetic field of a shielded three-phase busbar system

The paper presents the measurement results of the magnetic field in a shielded three-phase busbar system manufactured by Holduct Mysłowice. The measurements were performed with use of a specific non-directional magnetic field probe. In addition, also theoretical computations were done with use of finite elements. The results roughly agree, but at some probing points the differences are considerable, probably due to inaccurate positioning the probe between the bus bars.