다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

비만아 부모의 돌봄 경험: q 방법론

Overview of current development in electrical energy storage technologies and the application potential in power system operation

Hydrogen energy, economy and storage: Review and recommendation

Blockchains or distributed ledgers are an emerging technology that has drawn considerable interest from energy supply firms, startups, technology developers, financial institutions, national governments and the academic community. Numerous sources coming from these backgrounds identify blockchains as having the potential to bring significant benefits and innovation. Blockchains promise transparent, tamper-proof and secure systems that can enable novel business solutions, especially when combined with smart contracts. This work provides a comprehensive overview of fundamental principles that underpin blockchain technologies, such as system architectures and distributed consensus algorithms. Next, we focus on blockchain solutions for the energy industry and inform the state-of-the-art by thoroughly reviewing the literature and current business cases. To our knowledge, this is one of the first academic, peer-reviewed works to provide a systematic review of blockchain activities and initiatives in the energy sector. Our study reviews 140 blockchain research projects and startups from which we construct a map of the potential and relevance of blockchains for energy applications. These initiatives were systematically classified into different groups according to the field of activity, implementation platform and consensus strategy used. 1 Opportunities, potential challenges and limitations for a number of use cases are discussed, ranging from emerging peer-to-peer (P2P) energy trading and Internet of Things (IoT) applications, to decentralised marketplaces, electric vehicle charging and e-mobility. For each of these use cases, our contribution is twofold: first, in identifying the technical challenges that blockchain technology can solve for that application as well as its potential drawbacks, and second in briefly presenting the research and industrial projects and startups that are currently applying blockchain technology to that area. The paper ends with a discussion of challenges and market barriers the technology needs to overcome to get past the hype phase, prove its commercial viability and finally be adopted in the mainstream.

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Blockchain technology in the energy sector: A systematic review of challenges and opportunities

The author wishes to make a change to the mail address of Dr [...]

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Correction: Evans et al. Salt Cavern Exergy Storage Capacity Potential of UK Massively Bedded Halites, Using Compressed Air Energy Storage (CAES). Appl. Sci. 2021, 11, 4728

Battery energy storage systems (BESS) have been widely used in grid services. This paper focuses on BESS's participations in grid price arbitrage with considerations of three battery life models that account different factors for battery degradation. The BESS is optimized for maximizing the lifetime value using dynamic programming algorithms. Four cases are studied: case 1 - no battery degradation accounted; case 2 - an empirical battery degradation model using charge-discharge rate (Crate); case 3 - a semi-empirical model using Crate and the cell temperature; and case 4 - a new model that considers the influence of the battery's state of energy, Crate, and current state of health (SOH) on the battery aging rate. Taking the results of case 1 as a comparison benchmark, the battery SOH and power fluctuations of cases 2, 3, and 4 are much smoother, and the number of charge and discharge cycles during operation is reduced by 51.14%, 15.07%, and 66.23% respectively. In case 2, 3, and 4, after one year of continuous operation, the battery SOH decreases from 0.95 to 0.898, 0.89, and 0.9, respectively, leading to varied battery profits. These insights indicate the importance of selecting an appropriate battery degradation modelling in the controller design for BESS applications.

Impacts of Battery Degradation Modelling on the Battery Controller Design for Grid Arbitrage

Abstract The optimal control, for a class of nonlinear neutral evolution equations involving Riemann–Liouville fractional derivative, is investigated in this paper by using Darbo–Sadovskii fixed point theorem. An example is given in the last section to illustrate the validity of the abstract conclusions.

Optimal control for a class of fractional order neutral evolution equations

A concept of nonlinear optimal control is introduced for IPMSM drives. The control configuration remains the same as for the conventional control with three PI controllers for the $d$ and $q$ axes currents and velocity, but these controllers are replaced by corresponding nonlinear optimal controllers. The proposed controllers include linear (with Linear Quadratic Regulator - LQR) parts and nonlinear optimal parts emulating the automatic adjustment of the LQR gains based on operating conditions. The nonlinear parts are designed based on Krasovskiy's optimality criterion leading to an explicit solution of the control design problem. The proposed controller possesses some robustness properties which is explored in simulations. Compared to the conventional system, it allows to reduce velocity overshoot and torque oscillations without extending the transient times. The control concept is validated using a test rig.

Nonlinear Optimal Control for Interior Permanent Magnet Synchronous Motor Drives

Compressed air energy storage is a well-used technology for application in high voltage power systems, but researchers are also investing efforts to minimize the cost of this technology in medium and low voltage power systems. Integration of this energy storage requires a robust control of the power electronic converter to control the power injection due to the dynamic behavior of the system. The conventional linear control design requires a thorough knowledge of the system parameters, but the uncertain disturbances caused by the mechanical properties of the energy storage is neglected in the design and the system fails in presence of such instances. In this paper an adaptive control-based boost converter and sliding mode control-based three phase inverter for a grid integrated compressed air energy storage system of up to 1 kW has been presented that can mitigate any uncertain disturbances in the system without prior knowledge of the system parameters. The experimental results along with the simulation results are also presented to validate the efficiency of the system.

Jihong Wang

Papers

Correction: Evans et al. Salt Cavern Exergy Storage Capacity Potential of UK Massively Bedded Halites, Using Compressed Air Energy Storage (CAES). Appl. Sci. 2021, 11, 4728

Impacts of Battery Degradation Modelling on the Battery Controller Design for Grid Arbitrage

Optimal control for a class of fractional order neutral evolution equations

Nonlinear Optimal Control for Interior Permanent Magnet Synchronous Motor Drives

Application of Modern Non-Linear Control Techniques for the Integration of Compressed Air Energy Storage with Medium and Low Voltage Grid