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Developing a reliable power grid and investing in non-conventional renewable energy resources pose problems for low- and medium-income countries. Frequently, maintaining a robust power grid infrastructure can present challenges in terms of reliability, resilience, and flexibility. This article presents a methodology for improving power flexibility in susceptible power systems through the utilization of Battery Energy Storage Systems (BESS). The methodology entails the examination of power stability, operating conditions, and security criteria in order to identify suitable locations for storage allocation. A study was conducted utilizing the Electrical Transient and Analysis Program (ETAP®) software to simulate the Central American power transmission grid. The results of the study indicate that including storage systems to offer virtual inertia and backup during emergency situations is a recommended strategy for mitigating potential challenges. The study suggests that applying specific criteria for allocation and sizing at critical points in sensitive systems can enhance power transfer flexibility, eliminating potential constraints. The Central American electrical Power System, which faces power transfer limitations, is well-suited for BESS. In severe contingencies, such as when the system frequency drops to 58.75 Hz and power transfer between Mexico and Central America exceeds 300 MW with voltage levels below 0.97 pu, BESS can help mitigate these issues. The solution involves deploying BESS both centrally and distributively. Results show decreased instability, with power increases not exceeding 300 MW for more than 11 study cycles in all scenarios. The approach includes a BESS with an installed capacity of 1,060 MWh/160 MW and a virtual inertia of H=6s.
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BACKGROUND: Women's artistic gymnastics (WAG) is a complex aesthetic sport in which athletes start at a young age and are exposed to high loads during their careers. Little is known about the external and internal training load characteristics among elite young gymnasts. HYPOTHESIS: High training loads, with variations over the weeks, are expected. There is a relationship between external and internal load variables. STUDY DESIGN: Cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Seven elite-level Brazilian youth artistic gymnasts (age, 11.3 ± 0.4 years; mass, 33.0 ± 7.0 kg; height, 137.7 ± 10.6 cm; experience, 4.0 ± 1.2 years) participated in this study. Five nonconsecutive microcycles were monitored. Both external and internal training loads were quantified by counting the number of elements in video recordings of training sessions and by the session rating of perceived exertion method. RESULTS: A total of 168 individual training sessions were monitored. The microcycle that succeeded the main competition showed a significantly lower training load than ≥3 of the other 4 microcycles for all training load variables, except for vault elements, of which microcycle 4 was inferior only to the microcycle before the competition. Significant correlations were found between weekly internal training load and the total of elements and elements performed on uneven bars. CONCLUSION: Youth women's artistic gymnasts present fluctuations in external and internal training load variables over the weeks close to a major competition. Training load management in this sport must consider the specificity of each apparatus, as they have different demands and training load behaviors. CLINICAL RELEVANCE: A better comprehension of external and internal training loads in youth WAG and its apparatuses can benefit coaches and support staff and provide more information to overcome the challenge of training load management in gymnastics.
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Introduction: The aim of this study was to analyze the effects of space and number of players manipulation on the external and internal load demands of youth futsal athletes. Methods: Forty-two male U17 players (age = 15.62 ± 0.58 years) from three futsal teams participated in the study. In this cross-sectional study that lasted 8-week, the player's sample practiced six futsal tasks (T1-T6) and a futsal game played under the official rules (T7). From T1-T6, two task constraints were manipulated: (i) the number of players and, (ii) the space of play. The WIMU PRO™ Ultra-Wideband (UWB) tracking system was used to measure the external and internal load during the futsal tasks. External load was quantified using kinematic and mechanical variables extracted from positional data and, the internal load was quantified using Heart rate (HR) and rating of perceived exertion (RPE). Repeated measures ANOVA was used for comparison purposes. Results: In general, the results showed high external (total distance, distance 18.1-21, above 21â Km/h, and high intensity acceleration and deceleration, p < 0.001) and internal load (heart rate average and rating of perceived exertion, p < 0.001) in the tasks with low number of players and high area. In relation to the match, the tasks with small relative area per player (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK in 20 × 20â m) promoted low external load. Conclusion: It was concluded that increasing the relative area by reducing the number of players involved in the tasks in the form of small-sided games (GK + 2 vs. 2 + GK and GK + 3 vs. 3 + GK), in relation to the futsal game (GK + 4 vs. 4 + GK), can be considered a pedagogical strategy to increase the external and internal load demands of young futsal players.