Siting and capacity configurations of static transfer switches for three-phase unbalance governance in rural distribution networks: a bi-level optimization programme

Introduction:Mitigating three-phase unbalance in rural distribution networks is a significant challenge, especially with the integration of photovoltaic and energy storage systems (PESS). While Distributed Static Transfer Switches (STS) offer a promising solution by regulating load phase sequences, conventional approaches are costly and inefficient, limiting large-scale implementation.Methods:To address these limitations, we propose a bi-level optimization model for the siting and capacity optimization of STS in rural networks. The upper-layer model focuses on minimizing investment and maintenance costs for STS, while considering branch loss reduction and three-phase unbalance mitigation. The lower-layer model aims to minimize three-phase unbalance in daily operations, with the integration of PESS. We use the hyperparameter alternating iteration (HAI) method to iteratively refine the bi-level model and obtain optimal planning and operational solutions.Results:We applied the proposed model to an IEEE-13 benchmark case study. The results demonstrated that the bi-level optimization approach effectively reduced three-phase unbalance in the rural distribution system while minimizing STS planning costs.Discussion:This innovative approach provides a cost-effective and efficient solution for mitigating three-phase unbalance in rural distribution networks, enhancing the feasibility of large-scale STS deployment. The integration of PESS further contributes to system stability, making this model a robust tool for future network planning

Enhanced artificial bee colony with novel search strategy and dynamic parameter

There is only one guiding solution in the search equation of Gaussian bare-bones artificial bee colony algorithm (ABC-BB), which is easy to result in the problem of premature convergence and trapping into the local minimum. In order to enhance the capability of escaping from local minimum without loss of the exploitation ability of ABC-BB, a new triangle search strategy is proposed. The candidate solution is generated among the triangle area formed by current solution, global best solution and any randomly selected elite solution to avoid the premature convergence problem. Moreover, the probability of crossover is controlled dynamically according to the successful search experience, which can enable ABC-BB to adapt all kinds of optimization problems with different landscapes. The experimental results on a set of 23 benchmark functions and two classic real-world engineering optimization problems show that the proposed algorithm is significantly better than ABC-BB as well as several recently-developed state-of-the-art evolution algorithms.</jats:p

Functional Nanomaterials: From Structures to Biomedical Applications

In recent decades, a number of functional nanomaterials have attracted a great amount of attention and exhibited excellent performance for biomedical and pharmaceutical applications [...

Brain abscess caused by in an immunocompetent patient: a case report and literature review

Brain abscesses caused by Mycobacterium tuberculosis are rarely reported and are typically found in immunocompromised patients. The challenges in identifying the pathogen and the frequent delays in initiating appropriate therapy often result in a poor prognosis for patients. We herein report a rare case of a brain abscess caused by M. tuberculosis in a 63-year-old patient with a history of hypertension but no history of pulmonary tuberculosis. The patient was hospitalized twice because of worsening right upper limb weakness and speech difficulties. Both a pus culture and cerebrospinal fluid culture were negative. Ultimately, the diagnosis of M. tuberculosis infection was confirmed through next-generation sequencing and the tuberculosis-specific T-cell test (T-SPOT). The patient’s symptoms improved following anti-tuberculosis treatment. This case highlights the importance of considering M. tuberculosis as a potential cause of brain abscesses, even in immunocompetent individuals, and underscores the need for early diagnosis for effective treatment

Research and Application of Automatic Fault Diagnosis and Isolation Device for Distribution Line

This paper takes the equipment of a specific project as an example to develop an automatic fault diagnosis and isolation device for 10kV overhead line or cable line when a user has grounding and shortcircuit faults, so as to realize fast fault location, isolation and recovery, reduce the power outage time of users, and thus improve the reliability of distribution network. The project takes the 10kV South and North Trunk Lines ‘hand in hand’ power supply network as the research object, and studies the solutions of the automatic fault isolation function and the restoration of power supply, hoping to further improve the level of rapid power recovery, reduce power loss, and improve the reliability, automation and information level of power supply for reference.</jats:p