Coordinated Control of Energy Storage in Networked Microgrids under Unpredicted Load Demands

In this paper a nonlinear control design for power balancing in networked microgrids using energy storage devices is presented. Each microgrid is considered to be interfaced to the distribution feeder though a solid-state transformer (SST). The internal duty cycle based controllers of each SST ensures stable regulation of power commands during normal operation. But problem arises when a sudden change in load or generation occurs in any microgrid in a completely unpredicted way in between the time instants at which the SSTs receive their power setpoints. In such a case, the energy storage unit in that microgrid must produce or absorb the deficit power. The challenge lies in designing a suitable regulator for this purpose owing to the nonlinearity of the battery model and its coupling with the nonlinear SST dynamics. We design an input-output linearization based controller, and show that it guarantees closed-loop stability via a cascade connection with the SST model. The design is also extended to the case when multiple SSTs must coordinate their individual storage controllers to assist a given SST whose storage capacity is insufficient to serve the unpredicted load. The design is verified using the IEEE 34-bus distribution system with nine SST-driven microgrids.Comment: 8 pages, 10 figure

Mass Psychogenic Illness: Demography and Symptom Profile of an Episode

Background. Mass psychogenic illness has been a recurrent phenomenon in Bangladesh over recent times. Objectives. This study was aimed at investigating the demographic characteristics and symptom profile of an outbreak of mass psychogenic illness occurring in a girls’ high school. Methods and Materials. In 14 April 2013, a total of 93 students of a girls’ high school suddenly developed various symptoms following intake of tiffin cake which resulted in panic and hospital admission. A descriptive, cross-sectional observational survey was done to define various characteristics of the outbreak. Results. No organic explanation for the reported illnesses was found. 93 female students were included who were hospitalized during the incident. Trigger factor was found in 98% of students. Most of the students were 13 years old. Average interval between exposure to the trigger and onset of symptoms was 151.5 minutes. Commonest symptoms were abdominal pain (83%), headache (73%), chest pain (69%), body ache (63%), nausea (69%), and generalized weakness and fatigue (61%). Hospital stay following the incident was about 12 hours on average. Conclusion. To avoid unnecessary panic in the community a prompt, coordinated response is important in resolving widespread community anxiety surrounding these episodes

Health-related quality of life (HRQoL) and associated factors in Bangladeshi adolescents during COVID-19.

Publication status: PublishedBACKGROUND AND AIMS: The COVID-19 pandemic and its accompanying countermeasures significantly disrupt the health-related quality of life (HRQoL) of adolescents. We aimed to estimate the status and associated factors related to HRQoL of adolescents during the COVID-19 pandemic from the community population of Bangladesh. METHODS: This cross-sectional study followed two-stage sampling. From eight administrative divisions of Bangladesh, 2030 adolescents were enrolled. The KIDSCREEN-10 index was used to measure the HRQoL of adolescents. In addition to this, adolescents' data on sociodemographics, mental well-being, parenting style, insomnia, food insecurity, depression, anxiety and stress, resilient coping, screen-based activity, and anthropometry were taken for finding out the factors associated with HRQoL of adolescents. The hierarchical multilinear regression was performed to assess the association. RESULTS: More than 47% of adolescents were found to have moderate and high HRQoL, while 4.7% of adolescents experienced low HRQoL during data collection. Higher age (B: -0.671), having more siblings (B: -0.316), food insecurity (B: ‒2.010), depression (B: ‒0.321), anxiety (B: ‒0.362), and stress (B: ‒0.150) were found to have significantly negative associations with adolescents' HRQoL during the COVID-19 pandemic. Whereas, positive parenting (B: 0.409), inconsistent parenting discipline (B: 0.266), good mental health (B: 5.662), resilient coping (B: 0.306) were found to have significant positive relationships. CONCLUSIONS: The findings from this study indicate that over 52% of the adolescents reported a moderate and lower level of HRQoL. In light of these results, it may be beneficial to prioritize interventions targeting psychological factors such as depression, anxiety, and stress