Abstract-In this paper, a single-phase high-frequency AC (HFAC) microgrid is shown as a novel solution towards integrating renewable energy sources in a distributed generation system. Better utilization of the Microgrid is achieved by solving power flow and power quality issues using p-q theory-based active filtering called universal active power line conditioner and unified power quality conditioner, respectively. A distributed intelligent energy management system (DIEMS) is implemented to optimize operating costs. As the optimization greatly depends on the power generation and the power output from renewable sources strongly depends on the weather, the forecast of power generation is required for DIEMS. A Fuzzy ARTMAP neural network is used to predict hourly day-type outputs based on which generation can be forecasted. Depending on the forecast, an optimization scheme is developed utilizing linear programming along with heuristics. The results obtained show the successful implementation of HFAC Microgrid with adequate power flow and power quality control, as well as the optimization of operation cost by the DIEMS with Fuzzy ARTMAP-based day-type forecasting. The improvement in the battery life is also achieved due to optimization of storage charge states using the proposed DIEMS.Index Terms-Active filters, distributed intelligent energy management system (DIEMS), fuzzy ARTMAP, high-frequency AC (HFAC), linear programming, microgrid, unified power quality conditioner (UPQC), universal active power line conditioner (UPLC).

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In our recent work [1] we constructed a reduced-order model of the Western Electricity Coordinating Council (WECC) power system using mathematically derived parameters from real Synchrophasor data. These parameters include inter and intra-area impedances, inertias, and damping factors for aggregate synchronous generators representing five geographical, and yet coherent, areas of WECC. In this paper we use this reduced-order model as a tool to design a supplementary controller for a Static VAr Compensator (SVC), located at the terminal bus of one of the aggregate generators. Widearea feedback consisting of phase angle and frequency measurements from Phasor Measurement Units (PMUs) in the other areas is used to design this controller. The objective is to damp the inter-machine oscillation modes of the reduced-order model, which in the full-order system corresponds to inter-area oscillations. The controller input is chosen via statistical variance analysis, and its parameters are tuned to improve the damping factors of the slow modes. The model is implemented in a real-time digital simulator, and validated using a wide range of disturbance scenarios. The closed-loop system is observed to be highly robust to all of these disturbances as well as the

Study Objectives A pilot study to examine the effects of intermittent nocturnal hypoxia on sleep, respiration and cognition in healthy adult humans. Methods Participants were eight healthy, non-smoking subjects (four male, four female), mean age of 26.4 ± 5.2 years, and BMI 22.3 ± 2.6 Kg/m2, exposed to nine hours of intermittent hypoxia between the hours of 10 P.M. and 7 A.M. for 28 consecutive nights. At a simulated altitude of 13,000 feet (FIO2 0.13), intermittent hypoxia was achieved by administering nasal nitrogen, alternating with brief (approximately five seconds) boluses of nasal oxygen. Pre and post exposure assessments included polysomnography, attention (20-minute Psychomotor Vigilance Test), working memory (10-minute verbal 2 and 3-back), Multiple Sleep Latency Test, and the Rey Auditory Verbal Learning Test. Obstructive and non-obstructive respiratory events were scored. Results Overall sleep quality showed worsening trends but no statistically significant change following exposure. There was no difference after hypoxia in sleepiness, encoding, attention or working memory. Hyperoxic central apneas and post-hyperoxic respiratory instability were noted as special features of disturbed respiratory control induced by intermittent nocturnal hypoxia. Conclusions In this model, exposure to nocturnal intermittent hypoxia for 4-weeks caused no significant deficits in subjective or objective alertness, vigilance, or working memory.

Concern has been raised that the electrical grid of this nation is vulnerable to prolonged collapse. The postulated mechanisms are geomagnetic storms, electromagnetic pulse attacks (EMP) via a high altitude nuclear detonation, cyberattacks, and kinetic attacks. The likelihood of such events and the consequences to the American public of a protracted electric power failure are reviewed.