The article presents the analysis of the simulation test results for three variants of the power electronics used as interface between the power network and superconducting magnetic energy storage (SMES) with the following parameters: power of 250 kW, current of 500 A DC and voltage of 500 V DC. Three interface topologies were analyzed: two-level AC-DC and DC-DC converters; three-level systems and mixed systems combining a three-level active rectifier and a two-level DC-DC converter. The following criteria were considered: input and output current and voltage distortions, determined as THDi and THDu, power losses in power electronics components; cost of the semiconductor components for each topology and total cost of the interface. Results of the analysis showed that for high-power low-voltage and high-current power electronics systems, the most advantageous solution from a technical and economical perspective is a two-level interface configuration in relation to both AC-DC and DC-DC converters.
The objective of this research is to investigate the perception of owner – managers and
their employees regarding entrepreneurial leadership. To develop the research, two questions
are raised related to the similarities or differences of the perceptions of both groups
with what is established in the literature and between the self – evaluation of the owner –
managers and their employees on whether the former perform as an entrepreneurial leader.
As a research method, both groups are asked to perform, first individual evaluations and
then to match certain behaviours and the levels at which they should appear at certain levels
of entrepreneurial leadership capacity. The data gathered during the investigation were
processed using the Categorical Principal Components Analysis and revealed the similarities
and differences between the perceptions of the owner-managers and their employees on
entrepreneurial leadership. In spite of not finding significant differences between what is established
in the literature and among the perceptions of the groups under study, interesting
nuances stand out that, if not identified and understood, could have a negative effect on
the performance of SMEs. The results of the research demonstrated the importance of the
approach of behaviour and perception in the study of entrepreneurial leadership.