Inertia Supervision for BESS Grid-forming Inverter TESI DI LAUREA MAGISTRALE IN Electrical ENGINEERING INGEGNERIA Elettrica Author: Seifeldin Nafea-POLITECNICO MILANO

Inertia Supervision for BESS Grid-forming Inverter TESI DI LAUREA MAGISTRALE IN Electrical ENGINEERING INGEGNERIA Elettrica Author: Seifeldin Nafea 

 Introduction 

 In recent years, the renewable energy generation started to rise dramatically for most countries. In Europe, following the introduction of the renewable energy directive 2009/28/EC, the region increased the share of renewable energies in energy consumption to 20% by 2020, according to Eurostat [1]. Out of such energy consumption, 23% was consumed by the electricity sector as the second highest source of energy consumption [1]. Nevertheless, renewable energy generation is expected to continue rising in the coming years as part of the decarbonization plan. The directive EU/2018/2001 has set the renewable energy target to reach 32% by the year 2030 [2]. Subsequently, a provisional agreement was accepted to raise that target to at least 42.5%, with an aim for 45% [2]. The Continuous rise of renewable generation in the electricity sector can cause some problems for the grid, which need to be addressed. In traditional power systems, the synchronous generator is the main source offering support to the grid through its kinetic energy and governor control. The synchronous machine has the capability to participate in the primary frequency control using the governor speed control mechanism and dampen the system dynamics through its inertia. However, the power converters connecting renewables with the grid do not possess such capabilities. In fact, their control structure is more focused on extracting the maximum power from the renewable source. With the growth of renewable energy sources, the use of synchronous machines is expected to decline, hence decreasing the system inertia and support [3]. Remarkable efforts are focused on developing a control approach that allows power converters to mimic the behavior of a synchronous machine. A captivating control family has emerged, called ‘Grid-forming Inverters,’ allowing the inverters to provide some of the synchronous machine functionalities like primary frequency control, oscillation damping, and contributing to system inertia. This control methodology is best suited to be implemented with batteries. The high ramp rate along with power and energy characteristics of batteries ensures compliance with the control output power signals. The grid-forming presents multiple control approaches [10], with the utmost attention focused on the so called “Virtual Synchronous Machine”. It directs the power converters to act in a similar manner to a synchronous generator, thus providing all its functions mentioned above.

FULL THESIS: https://www.politesi.polimi.it/retrieve/ba4f7e7c-20a1-4e1f-8f4b-e57e7549afc7/Inertia%20Supervision%20for%20BESS%20Grid%20Forming%20Inverter.pdf

M-ulti-objective operation strategy for a PV-integrated hybrid UPS-ESS using predictive heuristics and receding-horizon control-Seong-Soo Jeong-Department of Electrical and Computer Engineering The Graduate School Sungkyunkwan University

 

Abstract 

 A Multi-Objective Operation Strategy for a PV-Integrated Hybrid UPS–ESS using Predictive Heuristics and Receding-Horizon Control In recent industry, the adoption of renewable energy using photovoltaics (PV) has been promoted as part of efforts to address climate change. In precision manufacturing facilities, an uninterruptible power supply (UPS) is required to respond to momentary voltage sags and outages, and an energy storage system (ESS) is essential to compensate for the intermittent output of PV. Accordingly, this study investigates a multi-objective control strategy for a hybrid UPS–ESS (HUE) system integrated with PV. Short-term forecasts of load and PV generation are performed using a Long Short-Term Memory (LSTM) model. Based on these forecasts, the minimum state of charge (SOC) required to secure HUE reserve power and the target SOC for system operation are calculated at each time step. Subsequently, the weights of each objective function are derived using Multi-Criteria Decision Making (MCDM), and a real-time operation strategy is constructed by combining predictive heuristics and Receding-Horizon Control (RHC). The predictive heuristic determines charge and discharge actions under operational constraints, while RHC updates the control decision at each time step by incorporating both forecasted and actual values. The proposed control aims to maintain an adequate SOC headroom for UPS readiness, suppress grid peaks to reduce electricity costs, and limit unnecessary SOC fluctuations that accelerate battery degradation. Simulation results demonstrate that the proposed multi-objective operation strategy combining predictive heuristics and RHC outperforms the comparison scenarios in terms of SOC stability, grid operation reliability, and cost efficiency.

Development of Large-Scale Seawater Battery Cells for High Energy Density-저자 Youngjin Kim 발행사항 울산 : Ulsan National Institute of Science and Technology, 2023 학위논문사항 학위논문(박사) -- Ulsan National Institute of Science and Technology , Engineering Energy Engineering (Battery Science and Technology) , 2023

 

ABSTRACT Lithium-ion batteries (LIBs) are the most widely used rechargeable energy storage systems. However, the future expanding of the LIB technology is limited due to the high cost and scarcity of both core elements of lithium and cobalt. The use of cheap earth-abundant metals such as sodium, aluminum, potassium, calcium, and magnesium in their corresponding metal-based batteries which working on the same principle as LIBs, would greatly reduce the cost of battery technology. Nevertheless, despite the economic advantage of production process, the large-scale production of these metal-based batteries have been limited by their lower gravimetric and volumetric energy densities. Rechargeable seawater batteries (SWBs) are regarded as sustainable alternatives to Li-ion batteries due to the use of an unlimited and free source of Na ion active materials. Although many approaches including the introduction of new catalysts have successfully improved the performance of SWBs, reconsidering the cell design is an urgent requirement to improve the performance and scale up the production of practical batteries. In this study, by adjusting the maximum space efficiency, a rectangular cell is developed which due to its unique architecture, benefits from optimized contact to improve the overall charge transfer in the system. In view of the rigidity of the solid electrolyte, the novel cell model is intended to have adequate flexibility to be easily transported and practically utilized. At the same time as the development of the cell platform, energy efficiency was also improved by improving the materials and assembly methods for each part of the seawater battery, which will be an indicator for future battery development. Furthermore, the enhanced efficiency of the parallel stacked modules, indicates the capability of this cell in practical use. The seawater battery module was actually operated in the ocean to prove its potential, and an automated pilot design for uniform cell production was also carried out. The designed catalyst-free cell system shows a record capacity of 3.8 Ah (47.5 Ah kg−1), energy of 11 Wh (137.5 Wh kg−1), and peak power of 523 mW for individual unit cell, while it also retains performance up to 100 cycles. This design paves the way for commercializing rechargeable seawater batteries.

ORIGINAL LINK: 

https://www.riss.kr/search/detail/DetailView.do?p_mat_type=be54d9b8bc7cdb09&control_no=b3b401c8481ee0b7ffe0bdc3ef48d419&keyword=BATTERY%20%20UPS%20%20IN%20PARALLEL

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