Full-scale Shaking Table Test of Uninterruptible Power Supply Installed in 2-stories Steel Structure 2-층 철골 구조물에 설치된 무정전전원장치의 실규모 진동대 실험연구-Lee, Ji-Eon ; Park, Won-Il ; Choi, Kyoung-Kyu (Department of Architecture Engineering, Soongsil University) ; Oh, Sang-Hoon ; Park, Hoon-Yang)KOREA

 

Full-scale Shaking Table Test of Uninterruptible Power Supply Installed in 2-stories Steel Structure 2층 철골 구조물에 설치된 무정전전원장치의 실규모 진동대 실험연구 Lee, Ji-Eon ; Park, Won-Il ; Choi, Kyoung-Kyu (Department of Architecture Engineering, Soongsil University) ; Oh, Sang-Hoon ; Park, Hoon-Yang 

이지언 (숭실대학교 건축학부) ; 박원일 (숭실대학교 건축학부) ; 최경규 (숭실대학교 건축학부) ; 오상훈 (부산대학교 건축공학과) ; 박훈양 ((주) 에너테크 기술연구소 Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회) 

 Abstract

 In this study, the shaking table tests were carried out on six types of non-structural elements installed on a full-scale two-story steel structure. The shaking table tests were performed for non-structural elements with and without seismic isolators. In this study, the seismic performance of Uninterruptible Power Supply (UPS) specimens was tested and investigated. Non-seismic details were composed of conventional channel section steel beams, and the seismic isolators were composed of high damping rubber bearing (HDRB) and wire isolator. The input acceleration time histories were artificially generated to satisfy the requirements proposed by the ICC-ES AC156 code. Based on the test results, the damage and dynamic characteristics of the UPS with the seismic isolator were investigated in terms of the natural frequency, damping ratio, acceleration time history responses, dynamic amplification factors, and relative displacements. The results from the shaking table showed that the dynamic characteristics of the UPS including the acceleration response were significantly improved when using the seismic isolator. 본 연구에서는 실규모의 2층 철골 구조물에 7종의 건축 및 비건축 비구조요소를 설치하여 진동대 실험을 수행하였다. 진동대 실험은 현행 비내진상세와 면진장치를 적용한 실험으로 두 차례 수행되었으며 본 연구에서는 무정전전원장치(UPS)의 내진성능에 대하여 실험 및 분석하였다. 비내진정착상세로는 UPS 하단에 ㄷ형강 다리부가 설치되었고, 면진장치로는 고감쇠고무와 와이어로프로 구성된 개발 복합면진장치가 사용되었다. 지진하중모사를 위하여 ICC-ES AC156 (2010)에 따라 인공지진파를 생성 후, 동일 지진파의 크기를 점증하여 가진하였다. 진동대실험을 통해 복합면진장치의 적용여부에 따른 UPS의 거동 및 동적 특성(응답가속도, 응답변위, 동증폭계수, 고유진동수, 감쇠비)을 비교 및 분석하였다. 실험결과, 복합면진장치를 적용함에 따라 UPS의 고유진동수가 감소하여 응답가속도 및 증폭계수가 크게 감소하는 것으로 확인되었다.

 ORIGINAL LINK KOREA:https://koreascience.kr/article/JAKO202220362436736.pub

ENGLISH TRANSLATED VERSION :

https://www.mediafire.com/file/w9fmh000y32rgny/Full-scale+Shaking+Table+Test+of+Uninterruptible+Power+Supply+Installed+in+2-stories+Steel+Structure.en.dual.pdf/file

TRANSLATED VERSION INTO PORTUGUESE:

https://www.mediafire.com/file/xc2aeuquo8ja1c7/Full-scale+Shaking+Table+Test+of+Uninterruptible+Power+Supply+Installed+in+2-stories+Steel+Structure.pt-BR.dual.pdf/file

A SYSTEM FOR STATE-OF-HEALTH DIAGNOSIS OF LEAD-ACID BATTERIES INTEGRATED WITH A BATTERY CHARGER Telles B. Lazzarin1 and Ivo Barbi2 1Federal Institute of Santa Catarina (IFSC), Florianópolis - SC, Brazil 2Federal University of Santa Catarina (UFSC), Florianópolis - SC, Brazil

 

A SYSTEM FOR STATE-OF-HEALTH DIAGNOSIS OF LEAD-ACID BATTERIES INTEGRATED WITH A BATTERY CHARGER 

Author Telles B. Lazzarin1 and Ivo Barbi

 Abstract – This paper reports a theoretical and experimental study on a proposal for a lead–acid battery charger applied in UPS, which has an integrated on-line test system to determine the state-of-health (SoH) of the batteries. The charger control structure is designed to ensure an appropriate charge for every battery in the pack. The battery evaluation system is based on historical analysis of the periodic measurements, such as internal impedance, DC voltage and operation temperature, performed for each battery. The periodic monitoring of these parameters provided by the integration of systems eliminates the disadvantages of online tests and thus allows the user to analyze the batteries adequately. The structure was experimentally verified on a prototype, where the battery SoH diagnosis system was integrated with a 1.5 kW battery charger. The system was designed for a bank of sixteen batteries associated in series.

LINK : https://journal.sobraep.org.br/index.php/rep/article/view/398/358

Comparative fire hazards of lithium-ion battery chemistries: Linking thermal behavior, gas toxicity, and state-of-charge to composite risk profiles Aamir Iqbal , Ashish Kakoria , Syed Talha Riaz , Jingmin Xu , Robert Illango Pushparaj , Guang Xu * Department of Mining and Explosives Engineering, Missouri University of Science and Technology, Rolla, MO, 65401, USA

 

ABSTRACT 

Lithium-ion batteries (LIB) are widely used in electric vehicles (EVs) for their high energy density. However, their fire safety causes concerns because of the toxic gases emission and the challenge to extinguish. The type and quantity of toxic gases released during battery fires remain among the least studied hazards, with limited data available despite their serious health risks. This study examines the thermal and gaseous emission behavior of LIB cells after thermal runaway (TR). Five cell types, Lithium Iron Phosphate (LFP), Lithium Titanate (LTO), and three Lithium Nickel Manganese Cobalt oxide (NMC). The three NMC variants share the same base formula (LiNiMnCoO2); NMC1 and NMC3 differ only by manufacturer, while NMC2 has added Ni and Co for enhanced performance. These cells were tested under controlled thermal abuse conditions using a Ni-Chrom resistance wire powered by a DC voltage regulator. Tests were conducted at five states of charge (0 %, 25 %, 50 %, 75 %, 100 % SOC). Temperature profiles and fire/explosion observations were recorded along with the ten types of gas release rates including Carbon Monoxide (CO), Methane (CH4), Carbon Dioxide (CO2), Ammonia (NH3), Ethene (C2H4), Propene(C3H6), Formaldehyde (CH2O), Acrolein (C3H4O), Hydrogen Cyanide (HCN) and Hydrogen Fluoride (HF). CO showed the highest levels of toxic emissions reaching 150–200 L/kWh. Peak emission rates were highest for CO2 across all chemistries. A quantitative risk assessment was performed by combining the measured factors into a risk index (RI). These data were visualized in a color-coded heat map, allowing comparison of overall hazard across chemistries and charge levels. Key contributions include the first systematic measurement of formaldehyde emissions during LIB fires and the introduction of a cell-level safety rating, an actionable safety tool. This study contributes to the understanding of gas emissions during LIB fire, and evaluates the risks related to the types of battery and SOC. 

 LINK:https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=3000&context=min_nuceng_facwork

Les nouvelles stratégies de contrôle d’onduleurs pour un système électrique 100% interfacé par électronique de puissance by Guillaume Denis-

 From grid-following to grid-forming: The new strategy to build 100 % power-electronics interfaced transmission system with enhanced transient behavior Les nouvelles stratégies de contrôle d’onduleurs pour un système électrique 100% interfacé par électronique de puissance 

 Thèse présentée en vue d’obtenir le grade de Docteur En Spécialité: Génie Électrique Par Guillaume Denis Doctorat délivré par Centrale Lille Résumé In the context of renewable energy and HVDC links development in power systems, the present work concerns the technical operations of such systems. As wind power, solar photovoltaics and HVDC links are interfaced to the transmission grid with power-electronics, can the system be operated in the extreme case where the load is fed only through static converters?Driving a power system only based on power electronic interfaced generation is a tremendous change of the power system paradigm that must be clearly understood by transmission grid operators. The traditional “grid-feeding” control strategy of inverters exhibits a stability limit when their proportion becomes too important. The inverter control strategy must be turned into a “parallel grid-forming” strategy.This thesis first analyses the power system needs, proposes the requirements for “parallel grid-forming” converters and describes the associated challenges. Accordingly, the thesis gives a method for designing a stable autonomous synchronization controls so that grid-forming sources can operate in parallel with a good level of reliability. Then, a method is proposed to design a voltage control for a grid-forming PWM source taking into account the limited dynamic of large converters. The robustness of the solution is discussed for different configuration of the grid topology. A current limiting strategy is presented to solve the current sensitivity issue of grid-forming converters, subject to different stressing events of the transmission grid. The ideas developed on a single converter are then applied on small grids with a limited number of converters to allow a physical interpretation on the simulation results.

VIEW FULL THESIS: https://hal.science/tel-01905827v1

Direct AC Voltage Control for Grid-Forming Inverters Taoufik Qorai , Chuanyue Li , Ko Oue , Francois Gruson , Fréderic Colas , Xavier Guillaud

Direct AC Voltage Control for Grid-Forming Inverters Taoufik Qorai (1) , Chuanyue Li (1) , Ko Oue (1) , Francois Gruson (1) , Fréderic Colas (1) , Xavier Guillaud (1) 

 Résumé 

 Grid-forming inverters usually use inner cascaded controllers to regulate output AC voltage and converter output current. However, at the power transmission system level where the power inverter bandwidth is limited, i.e., low switching frequency, it is difcult to tune controller parameters to achieve the desired performances because of control loop interactions. In this paper, a direct AC voltage control-based state-feedback control is applied. Its control gains are tuned using a linear quadratic regulator. In addition, a sensitivity analysis is proposed to choose the right cost factors that allow the system to achieve the imposed specifcations. Conventionally, a system based on direct AC voltage control has no restriction on the inverter current. Hence, in this paper, a threshold virtual impedance has been added to the state-feedback control in order to protect the inverter against overcurrent. The robustness of the proposed control is assessed for diferent short-circuit ratios using smallsignal stability analysis. Then, it is checked in diferent grid topologies using time domain simulations. An experimental test bench is developed in order to validate the proposed control.

FUL PAPER: https://hal.science/hal-02458108v1