Optimized operation of large scale battery systems

In the decentralized renewable driven electric energy system, economically viable battery systems become increasingly important for providing grid-related services. End of 2016, STEAG has successfully started the commercial operation of six 15 MW large scale battery systems which have been incorporated in STEAG’s primary control pool. During the commissioning phase, extensive effort has been spent in optimizing the operational efficiency of these systems with promising results. However, the operation experience has shown that there is still significant potential for improving the system behavior as well as reducing the aging of the battery cells. By analyzing historical data of the charging power associated with the state of charge management, opportunities for significantly reducing the operational costs have been identified. By means of more involved model-based control strategies, which adequately consider the specific characteristics of the battery system, and by using mathematical optimization and artificial intelligence, adapting the state of charge management strategy to new applications, these additional cost savings can be obtained. Apart from giving insights into the operational experience with large scale battery systems, the contribution of this paper lies in proposing strategies for reducing the operational costs of the battery system using classical approaches as well as mathematical optimization and neural networks. These approaches will be illustrated by simulation results.

CO2 Liquefaction Close to the Triple Point Pressure

For vessel-based transport of liquid CO2 in carbon capture and storage chains, transport at 8 bar(a) enable significant cost reductions compared to transport at higher pressures for most transport distances and volumes. Transport at even lower pressures could further reduce the costs. There are, however, concerns related to dry ice formation and potential clogging in parts of the chain that could lead to operational issues when operating close to the triple point pressure of CO2. In this paper, results from an experimental campaign to de-risk and gain operational experience from the low-pressure CO2 liquefaction process are described. Six experiments using pure CO2 or CO2/N2 mixtures are presented. In four of the experiments, the liquid product pressure was continuously lowered until dry ice was detected and eventually clogged the system. In the final two experiments, the liquefaction process was run in steady-state at low liquefaction pressures for five hours to ensure that there is no undetected dry ice in the process that could lead to accumulation and operational issues over time. These experiments demonstrate that pure CO2 can be safely liquefied at 5.8 bar(a) and a CO2/N2 mixture can be liquefied at 6.5 bar(a) without issues related to dry ice formation.

A Continuous Taxi Pickup Path Recommendation under The Carbon Neutrality Context

In the context of the carbon neutrality target, carbon reduction in the daily operation of the transportation system is more important than that in productive activities. There are few travel services that can quantify low-carbon travel, with a lack of effective low-carbon travel tools to guide transportation behavior. On-demand access to taxi services can effectively reduce the additional carbon emissions caused by cruising, which in turn increases efficiency in urban mobility with a reduced taxi fleet scale. For individual taxis, they lack macroscopic horizon in their choice of passenger pickup paths. The selected travel path based on personal operational experience or real-time location is limited by local optimization when making path decisions. In this work, we proposed a macro-path recommendation method to assist the taxi pickup path selection to accelerate the transformation of the taxi system towards low-carbon sharing. First, an adaptive learning spatiotemporal neural network was used to predict the coarse-grained distribution of potential trips. Next, the trajectory sharing graph was constructed based on the potential trips distribution to reallocate the taxi orders for the continuous pickup path optimization. As a result, the continuous pickup path balanced the relation between travel demands and taxi supply, improving the economic and environmental benefits of taxi operation and contributing to the goal of carbon neutrality. We conducted experiments on the Chengdu city ride-hailing dataset. Compared with the current status of taxi operations, the solution shows improvements in both the scale of taxi services and order gain.

Navigating Pandemic Responsiveness in an Acute Care Setting: A Community Hospital’s Operational Experience with COVID-19

Background To ensure continuity of services while mitigating patient surge and nosocomial infections during the coronavirus disease 2019 (COVID-19) pandemic, acute care hospitals have been required to make significant operational adjustments. Here, we identify and discuss key administrative priorities and strategies used by a large community hospital located in Barrie, Ontario to manage COVID-19. Methods Guided by a qualitative descriptive approach, we conducted a thematic analysis of all COVID-19-related documentation discussed by the hospital’s Emergency Operations Centre (EOC) during the first pandemic wave. We solicited operational strategies from administrative leaders to construct a narrative for each theme. Results Seven recurrent themes critical to the hospital’s pandemic response emerged: 1) Organizational Structure: a modified EOC structure was adopted to increase departmental interoperability and situational awareness; 2) Capacity Planning: Design Thinking guided rapid infrastructure decisions to meet surge requirements; 3) Occupational Health and Workplace Safety: a multidisciplinary team provided respirator fit-testing, critical absence adjudication, and wellness needs; 4) Human Resources/Workforce Planning: new workforce planning, recruitment, and redeployment strategies addressed staffing shortages; 5) Personal Protective Equipment (PPE): PPE conservation required proactive sourcing from traditional and non-traditional suppliers; 6) Community Response: local partnerships were activated to divert patients through a non-referral-based assessment and treatment centre, support long-term care and retirement homes, and establish a 70-bed field hospital; and 7) Corporate Communication: a robust communication strategy provided timely and transparent access to rapidly evolving information. Conclusions The hospital benefited from an interconnected command structure that focused on inter-operability, communication, novel administrative tools, and community partnerships.

Sustenance of Indian Moored Buoy Network During COVID-19 Pandemic – A Saga of Perseverance

The moored buoy network in the Indian Ocean revolutionized the observational programs with systematic time-series measurement of in situ data sets from remote marine locations. The real-time meteorological and oceanographic data sets significantly improved the weather forecast and warning services particularly during extreme events since its inception in 1997. The sustenance of the network requires persistent efforts to overcome the multitude of challenges such as vandalism, biofouling, rough weather, corrosion, ship time availability, and telemetry issues, among others. Besides these, the COVID-19 pandemic constrained the normal functioning of activities, mainly by delaying the maintenance of the network that resulted in losing a few expensive buoy system components and precious data sets. However, the improvements in the buoy system, in-house developed data acquisition system, and efforts in ensuring the quality of measurements together with “best practice methods” enabled 73% of the buoy network to be functional even when the cruises were reduced to 33% during the COVID-19 lockdown in 2020. The moored buoys equipped with an Indian buoy data acquisition system triggered high-frequency transmission during the Super cyclone Amphan in May 2020, which greatly helped the cyclone early warning services during the COVID-19 pandemic. The COVID-19 lockdown points toward the reliability and enhanced utility of moored buoy observations particularly when other modes of measurements are limited and necessitates more such platforms to better predict the weather systems. The present study analyzed the enhancement of the buoy program and improvisation of the buoy system that extended the life beyond the stipulated duration and enabled the high-frequency data transmission during cyclones amid the COVID-19 lockdown. The recommendations to better manage the remote platforms specifically in the event of a pandemic based on the operational experience of more than two decades were also presented.

Performance of a triple-GEM demonstrator in pp collisions at the CMS detector

After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high η region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. Demonstrator GEM detectors were installed in CMS during 2017 to gain operational experience and perform a preliminary investigation of detector performance. We present the results of triple-GEM detector performance studies performed in situ during normal CMS and LHC operations in 2018. The distribution of cluster size and the efficiency to reconstruct high pT muons in proton-proton collisions are presented as well as the measurement of the environmental background rate to produce hits in the GEM detector.

The Tactical and Technical Functioning Conditions of the S-200C Vega Missile System on the Modern Battlefield

The Polish armed forces have used the S-200 Vega surface-to-air missile (SAM) system since the middle of the 1980s. In the early 21st century, it was upgraded to a digital version and adapted to the reality of air combat at the time. After almost twenty years of service since its upgrade, it remains the only long-range SAM in the armament of the Polish Air Force. Today, this SAM system is undergoing a major modification, again, to maintain its long-range anti-air attack potential and the required combat functionalities. The objective of this paper is to identify the technical and tactical functioning conditions of the S-200 family of SAM system on the modern battlefield. In order to achieve this goal, the authors used theoretical methods of research. As a result of the conducted analyzes, this paper presents the operational experience gained so far and a justification for the continued service of the Vega SAM system.

Creation of Optimal Design of Runner Oil System of Kaplan Hydro-Turbines

The main objectives of the reconstruction are stated. Those are: increase of the service life of the hydro-turbines of Dnipro Cascade, enhancement of their efficiency, power, and environmental safety, extension of the power control range of the hydro-power plants, assurance of the reliability and improvement of the operating safety of their equipment and structures, meeting the environmental requirements, improvement of the quality of the generated electric power after control system rehabilitation. The article deals with and analyses the chronology of the creation of the optimal design for a vertical Kaplan hydro-unit oil piping taking into consideration the half a century operational experience and stages of hydro-turbine modernization for Dnipro-2 HPP. The experience in improvement of the hydro-unit and oil head system control design is generalized, from the unified solution to the creation of the all-new design. The methods of the oil system rod machining and preliminary control are amended. The temperature control of the automatic unit shutdown in case of heating of oil head bushes is introduced into the control system. The oil piping installation method is improved and step-by-step checking of the oil piping installation centering is introduced. As a result of implementation of a package of design and process engineering solutions, the optimal design of the oil piping of improved reliability was created. It decreased the unscheduled downtime of the units and cut expenses on their maintenance providing the cyclic recurrence recommended by the standards for the operation of the oil pressure device pumps and thus, decreased the electric power consumption for balance-of-plant needs. The objects of the implementation of the developed oil piping design are given.