Realization of future low-voltage (LV) microgrids requires that all technical issues, such as power and energy balance, power quality and protection, are solved. One of the most crucial one is the protection of LV microgrid during normal and island operation. In this paper, protection issues of LV microgrids are presented and extensions to the novel LV-microgrid-protection concept has been developed based on simulations with PSCAD simulation software. Essential in the future-protection concept for LV microgrids will be the utilization of high speed, standard, e.g., IEC-61850-based communication to achieve fast, selective, and reliable operation protection.

The association of self-reported hostility with morbidity and mortality due to external causes, including suicidal acts, was analyzed in 10,586 Finnish men and 10,857 Finnish women aged 24 to 59 years. Hostility was assessed from self-ratings on irritability, ease of anger-arousal, and argumentativeness. Three groups, low (33.6% of subjects), intermediate (50.6%), and extreme (15.9%), were formed from the self-reported hostility scores. A 6-year mortality follow-up yielded 76 violent deaths among men and 11 among women. A 4-year morbidity follow-up found 399 hospitalizations due to external causes among men and 169 among women. Among men, the risk ratio between the highest and lowest hostility groups was 1.51 (95% confidence interval, 1.16-1.96) for all events due to external causes and 3.6 (95% confidence interval, 1.63-7.89) for suicidal behavior, when effects of age, marital status, social status, and self-reported alcohol use were controlled in a multivariate model. No association was observed between traffic-related injuries and hostility. Hostility did not predict accidents or accidental deaths or suicidal behavior among women.

In this paper voltage and frequency control of islanded microgrid after intentional and unintentional switching events are investigated. The weak low voltage (LV) network based microgrid consists of two inverter based distributed generation (DG) units. One unit is a storage (battery) unit and the other is a photovoltaic (PV) cell. In this case the battery inverter with rapid response is considered to act as a master and it has the main responsibility to control the voltage and frequency in microgrid when islanded from the main distribution network. The studies are performed on a PSCAD simulation software package. Simulation studies show the voltage -active power and frequency -reactive power dependency in weak LV network. The studies also show that in order to maintain frequency balance in islanded microgrid, there is need for a reference sine wave generator inside master unit which imitates the main network phase voltages and gives the input for master units' (battery storage) PLL (Phase Locked Loop) during islanding.

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