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In the dispersed generation system, power electronic converters allow for coupling between energy sources and the power grid. The requirements of Transmission System Operators are difficult to meet when the share of distributed energy sources of the total energy balance increases. These requirements allow to increase penetration of distributed generation sources without compromising power system stability and reliability. Therefore, in addition to control of active or reactive power, as well as voltage and frequency stabilization, the modern power electronic converters should support power grid in dynamic states or in the presence of nonlinear distortions. The paper aims to discuss these issues.

The research methodology used in this paper is based on three steps: Mathematical modelling and simulation studies, Experiments on laboratory test stand, Analyzing obtained results, evaluating them and formulating the conclusions.

The authors identified two algorithms, αβ-Filter and Voltage Controlled Oscillator, which are able to successfully cope with notch distortions. Other algorithms, used previously for voltage dips, operate improperly when the voltage grid has notching disturbances. This work evaluates six different synchronization algorithms with respect to the abilities to deal with notching.

The paper presents results of the synchronization algorithms in the presence of nonlinear notching interference. These studies were performed using the original hardware-software power grid emulator, real-time d’Space platform and power electronic converter. This methodology allowed us to exactly and accurately evaluate synchronization performance methods in the presence of complex nonlinear phenomena in power grid and power electronic converter. The results demonstrated that the best algorithms were αβ – Filtering and Voltage Controlled Oscilator.

In this paper, different synchronization algorithms have been tested. These included the classical Phase Locked Loop with Synchronous Reference Frame as well as modified algorithms developed by the authors, which displayed high robustness with respect to the notching interference. During the tests, the previously developed original test rig was used, allowing software-hardware emulation of grid phenomena.

Underpinning this research is an acknowledgement of the increasing attention paid to the social issues raised by young peoples' alcohol consumption. Although earlier research has identified a number of factors contributing to alcohol‐related problems in Poland, only a handful of studies attempted to better understand drinking patterns and their influence on alcohol consumption amongst Polish people. Therefore, this paper aims to explore the roles alcohol plays in the life of young people in Poland.

All the data are collected on a university campus in Poland in late autumn 2007 from a group of ten university students. The research is conducted in three phases, using two research methods: focus groups and diaries. Purposive sample is used to establish two focus groups (Phases 1 and 3) each of which meet on two occasions, three weeks apart. In the first two week period between each focus group, respondents are asked to keep private diary (Phase 2) recording every occurrence that is, in their opinion, related to alcohol consumption.

The findings are themed around three major factors: quantity of consumed alcohol, frequency of consumption and location of consumption. However, the strongest issue is the pressure experienced by students around the social consumption of alcohol.

At a time when young peoples' alcohol consumption is attracting increasing attention from legislators and regulators, a better understanding of young consumers' behaviour may help government and other non‐profit organisations create well‐informed regulations, policies or educational programmes.

Although there is significant amount of research into detrimental effects of excessive alcohol consumption on physical and psychological health of people in Poland, little research goes into wider social issues or beyond the most visible biological consequences of drinking as anti‐social behaviour.