Investigating Safety Standards and Performance of Emergency Power Diesel Generators in Hospitals of Tabriz, Iran

Background: Power outage risk is one of the serious risks that could be eliminated by supplying electricity through the emergency power system installed in a hospital, such as diesel generators and uninterruptible power supplies (UPSs). Objectives: The present study aimed to investigate the observance of safety and maintenance standards of emergency power diesel generators in the hospitals of Tabriz. Methods: This descriptive-analytical research was cross-sectionally performed in 18 hospitals of Tabriz in 2014. The data collection tools included a questionnaire and a checklist prepared according to the national standards and consisted of 87 questions in 15 categories. Data were analyzed using SPSS version 19. Results: The average rates of observance of safety and maintenance standards of diesel generators in 111-question standards and 87-question standards were equal to 61.4 and 52.8%, respectively. Regarding the observance of the 19 standards, “ventilation” and “daily visits” standards with 28.94 and 96.24, respectively, had the lowest and highest degrees of observance in hospitals. There was a significant direct association between observing the standards defined for diesel generators with the number of hospital beds (P = 0.01) and the total capacity of emergency power generation by generators (P = 0.05). Conclusions: The results of the present study indicate a low level of safety and maintenance for the emergency power systems of hospitals. These scores are not considered favorable for a system called “emergency”, and if the necessary interventions are not made in this regard, in the event of natural disasters and human errors, hospitals will face numerous problems.

Calculation apparatus for modeling the distribution of electromagnetic fields of different sources

The calculation apparatus acceptable for assumptions and simplifications and sufficient for errors of final results for modeling the propagation of electric, magnetic and electromagnetic fields spread over a certain area was proposed. It is shown that to model the propagation of ultra-low frequency electric and magnetic fields (monitors, uninterruptible power supplies, transformers, electric motors and generators) it is possible to consider these sources as dipole and dipole-quadrupole type sources. That is, the field of the local source can be considered as a combination of electric and magnetic dipoles. This makes it possible to delineate with sufficient accuracy the zones of exceeding the maximum allowable field strengths. The calculation apparatus used to determine the radiation intensities of civil aviation radar equipment was adapted to model the propagation of electromagnetic fields of very high and ultra-high frequencies. The calculations of coefficients that take into account the parameters of radiation patterns in the horizontal and vertical planes for the most common radiation sources are given. These ratios and corresponding coefficients can be used to determine the electromagnetic environment in the presence of many high-frequency sources (mobile communication base stations, navigation equipment, radio relay stations, etc.). The proposed approach allows to automate processes of designing the placement of electromagnetic, electronic and radio equipment in production areas and territories, as well as to assess the environmental impact at the stages of design work. This will make it possible to delineate the isolines of the limits of exceeding the maximum permissible levels of electric magnetic and electromagnetic fields for different frequency ranges and categories of equipment and to automatically determine the electromagnetic load at each point of the controlled space.

Application specific product qualification report for uninterruptible power supplies used in nuclear reactors R1 and R2

Safety is the most important aspect and is considered the overwriting priority in nuclear power plants, which comprise of thousands of systems and components that work systematically together for the purpose of generating electricity in a safe, economical and environmentally friendly manner. As the instrumentation and electrical components advance and become more sophisticated and migrate from analog design to the more complicated and error-prone software-based topology, the task of determining that a programmable electronic system (PES) is capable of meeting its safety-related design objective becomes ever more challenging. The dependence on the PES to accomplish its safety-related object must be thoroughly studied to assess the safety-related impacts associated with the potential failure modes of the device. Application Specific Product Qualification (ASPQ) is used to provide neccessay aasurance in the design integrity of a PES and confirms that the product can meet the requirements of a safety-related application. This report is an application specific product qualification (ASPQ) assessment of WEP 1010-110/120-NEA and WEP 1020-110/120-NEA Uninterruptible Power Supplies manufactured by Gambit Electronic Ltd. Information referenced in this report is based on the data received from Gambit, other nuclear power plants using Gambit products and the site visit paid to Gambit, Country-X in August 2007. Gambit WEP 1010- and 10XX-XXX/YY NEA UPS systems are used to provide uninterruptible Class II power to a number of safety-related control and instrumentation power distribution panels for R1 and R2 reactors located in X facility. These UPS are commercial Off-the Shelf (COTS) products intended for industrial uninterruptible power supply applications. An earlier Categorization Assessment Report concluded that UPS perform Category B safety-related functions and therefore, they must be qualified to meet the safety requirements associated with a Class BProgrammable Electronic System (PES) as per IEC 61513.A combination of methods were utilized to demonstrate that the UPS systems were suitable for the target applications, were inherently correct in design, and came with sufficient documentation to allow safe operation by the plant. The key findings of this report indicate that the aforementioned UPS systems are suitable for use in the target application, have strong evidence of reliability through field experience and various product certifications that support correctness of their design and come with thorough documentation that support safe operation and suitability assessment. Two major recommendations made in this report are to establishing a Preventive Maintenance (PM) program by the station to perform replacement of life-limiting components at the minimum frequencies specified by the manufacturerer, and to set ip an inspection and testing program by the station to perform minimum -monthly testing of the output power quality of the UPS systems to minimize the possibility of partial failure, which is the failure of concern and relates to a situation where the loads are supplied with out-of-specification power, undetected.

Application specific product qualification report for uninterruptible power supplies used in nuclear reactors R1 and R2

Safety is the most important aspect and is considered the overwriting priority in nuclear power plants, which comprise of thousands of systems and components that work systematically together for the purpose of generating electricity in a safe, economical and environmentally friendly manner. As the instrumentation and electrical components advance and become more sophisticated and migrate from analog design to the more complicated and error-prone software-based topology, the task of determining that a programmable electronic system (PES) is capable of meeting its safety-related design objective becomes ever more challenging. The dependence on the PES to accomplish its safety-related object must be thoroughly studied to assess the safety-related impacts associated with the potential failure modes of the device. Application Specific Product Qualification (ASPQ) is used to provide neccessay aasurance in the design integrity of a PES and confirms that the product can meet the requirements of a safety-related application. This report is an application specific product qualification (ASPQ) assessment of WEP 1010-110/120-NEA and WEP 1020-110/120-NEA Uninterruptible Power Supplies manufactured by Gambit Electronic Ltd. Information referenced in this report is based on the data received from Gambit, other nuclear power plants using Gambit products and the site visit paid to Gambit, Country-X in August 2007. Gambit WEP 1010- and 10XX-XXX/YY NEA UPS systems are used to provide uninterruptible Class II power to a number of safety-related control and instrumentation power distribution panels for R1 and R2 reactors located in X facility. These UPS are commercial Off-the Shelf (COTS) products intended for industrial uninterruptible power supply applications. An earlier Categorization Assessment Report concluded that UPS perform Category B safety-related functions and therefore, they must be qualified to meet the safety requirements associated with a Class BProgrammable Electronic System (PES) as per IEC 61513.A combination of methods were utilized to demonstrate that the UPS systems were suitable for the target applications, were inherently correct in design, and came with sufficient documentation to allow safe operation by the plant. The key findings of this report indicate that the aforementioned UPS systems are suitable for use in the target application, have strong evidence of reliability through field experience and various product certifications that support correctness of their design and come with thorough documentation that support safe operation and suitability assessment. Two major recommendations made in this report are to establishing a Preventive Maintenance (PM) program by the station to perform replacement of life-limiting components at the minimum frequencies specified by the manufacturerer, and to set ip an inspection and testing program by the station to perform minimum -monthly testing of the output power quality of the UPS systems to minimize the possibility of partial failure, which is the failure of concern and relates to a situation where the loads are supplied with out-of-specification power, undetected.

Model Predictive Control for Paralleled Uninterruptible Power Supplies with an Additional Inverter Leg for Load-Side Neutral Connection

Uninterruptible Power Supplies (UPS) have been demonstrated to be the key technology in feeding either single- and three-phase loads in a wide range of critical applications, such as high-tier datacenters and medical facilities. To increase the overall system power capacity and resilience, UPS systems are usually connected in parallel. When UPS systems are parallel connected, a circulating current can rise, inhibiting correct system operation. Moreover, having a controlled load power distribution is another fundamental requirement in paralleled UPS systems. However, strategies to ensure these two topics have not been explored to date for UPS systems with a load-side neutral connection. This paper proposes an innovative Finite Control Set Model Predictive Control (FCS-MPC) strategy that ensures circulating current elimination and controlled load power distribution for paralleled UPS systems that use an additional inverter leg for load neutral point connection. Additionally, a system topology based on two parallel-connected UPS systems that can simultaneously supply single- and three-phase critical loads is proposed. Experimental results show the effectiveness and robustness of the proposed control techniques even when different types of loads are connected to the UPS systems.

Improvement of control devices for road sections of railway automation and telemechanics

In this scientific article, control sensors and control devices have been improved based on the method of counting arrows of the rolling stock of railway transport. The microprocessor-controlled control unit and control system have been simplified to manage traffic between two stations, and a self-monitoring, reliable and risky scheme has been developed. Wiring diagrams of existing transport relays have been updated for uninterruptible power supplies, microprocessor devices, and sensors. An automated schematic diagram with a microprocessor for signaling a collision of a railway with wagons has been created, and the order in which the speed of train movement approaches the crossing has been maintained. The complex functional control of rolling stock was improved based on the method of counting bullets, electronic archiving of the movement of orders of the train attendant and dispatcher, as well as the operation of devices for monitoring the technical condition of the station.

Conversor CC-CC SEPIC Não Isolado de Alto Ganho Baseado na Célula de Comutação de Três Estados Empregando Células Multiplicadoras de Tensão

Conversores CC-CC não isolados com ampla taxa de conversão têm sido utilizados em uma vasta gama de aplicações modernas, incluindo sistemas de conversão de energias renováveis, sistemas de alimentação ininterrupta (uninterruptible power supplies – UPSs), entre outras. No entanto, muitas topologias são viáveis apenas para aplicações de baixa potência, sendo que outros aspectos além da taxa de conversão também são importantes como, por exemplo, número de componentes, esforços nos semicondutores e rendimento. Nesse contexto, este trabalho apresenta um conversor SEPIC (single-ended primary inductance converter) baseado na célula de comutação de três estados (three-state switching cell – 3SSC) e em células multiplicadoras de tensão (voltage multiplier cells – VMCs), o qual é capaz defornecer elevado ganho de tensão e esforços reduzidos nos semicondutores. O princípio de operação, a análise qualitativa e a análise quantitativa são descritos em detalhes. Além disso, resultados de simulação são apresentados para validar as considerações teóricas.

Nanostructured materials based on the bronze titanium dioxide for lithium batteries in large-sized engineering

В последние годы, стремительными темпами развивается целый ряд направлений промышленности, таких как гибридный и электрический автотранспорт, подводная робототехника, сфера бесперебойного энергообеспечения, прибрежная возобновляемая энергетика, и т.п., требующих от автономных накопителей энергии работы в жёстких условиях эксплуатации. Это диктует необходимость решения ряда задач, связанных с получением для них функциональных материалов с достаточно высокими удельными характеристиками, способностью стабильно и безопасно функционировать в широком температурном диапазоне и в условиях ускоренного заряда. В этой связи все больше внимания исследователями уделяется диоксиду титана. В рамках настоящего исследования получены наноленты диоксида титана со структурой бронз гидротермальным способом с использованием анатаза, состоящего из частиц различного размера. Обнаружено, что степень кристалличности и текстурные характеристики формирующегося TiO2-B определяются размером частиц и площадью поверхности стартового реагента. В свою очередь оба эти фактора оказывают значительное влияние на электрохимические характеристики бронзовой модификации TiO2: после 35 циклов заряда/разряда емкость составила 203 мА∙ч/г, а скорость деградации – 0,25% за цикл для материала, синтезированного из анатаза с размером частиц ~30 нм и площадью поверхности ~100 м2/г. В то же время образцы, полученные с использованием более крупных частиц, показывают худшие показатели емкости и циклируемости. Now, technology progress provides broad prerequisites for practical usage of batteries in the field of hybrid and electric vehicles, marine robotics, backup uninterruptible power supplies, coastal renewable energy sources, etc. with a more hard-working performance. This dictates the necessity of development an advanced electrode materials with a sufficiently high specific parameters, stability of operation and safely in a wide temperature range and under fast charge mode. In this way, a more attention has been paid to titanium dioxide. Herein, the titanium dioxide nanobelts with a bronze structure were obtained by the hydrothermal method using anatase with different particle size as a precursor. It was found that the degree of crystallinity and textural characteristics of as-formed TiO2-B are determined by the particle size and surface area of starting reagent. Both of these factors have a benefit effect on the electrochemical performance of TiO2-B: the capacity of 203 mA·h/g was registered after 35 charge/discharge cycles with a degradation of 0.25% per cycle for material synthesized from anatase with a particle size about ~30 nm (~100 m2/g). On the other hand, the samples prepared from a precursors with larger particles show the worst capacity and cyclability.

Finite Control Set Model Predictive Control for Paralleled Uninterruptible Power Supplies

Nowadays, uninterruptible power supplies (UPS) play an important role in feeding critical loads in the electric power systems such as data centers or large communication hubs. Due to the increasing power of these loads and frequent need for expansion or redundancy, UPS systems are frequently connected in parallel. However, when UPS systems are parallel-connected, two fundamental requirements must be verified: potential circulating currents between the systems must be eliminated and the load power must be distributed between the systems according to UPS systems availability. Moreover, a high-quality load voltage waveform must be permanently ensured. In this paper innovative control strategies are proposed for paralleled UPS systems based on Finite Control Set Model Predictive Control (FCS-MPC). The proposed strategies simultaneously provide: controlled load power distribution, circulating current suppression and a high-quality load voltage waveform. A new dynamic converters deactivation mechanism is proposed. This new technique provides improved overall system efficiency and reduced power switches stress. In this paper, two multilevel based UPS systems are parallel-connected. Each UPS contains two three-level Neutral Point-Clamped-Converters (3LNPC) and a three-level DC-DC converter. The presented experimental results demonstrate the effectiveness of the proposed control strategies in several operating conditions.