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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

Pneumatic actuators have been widely used in industry and many other applications. However, it has been recognized that the significant weakness of pneumatic actuators is low energy efficiency which is due to its open-circuit structure in nature. The paper presents a pneumatic-electricity system aiming at efficiency improvement by reusing the exhaust compressed air from the actuator outlets. A control strategy for the system is implemented to ensure recovering exhaust energy and maintaining proper actuator operation. The overall system mathematical model and the simulation results are presented in the paper. The model validation and the experimental test results for the overall system are also given. From the simulation study and the laboratory test analysis, the proposed system can operate at higher energy efficiency.

Control and energy efficiency analysis for a pneumatic-electrical system

The scroll-type air motor, also named the scroll expander, has been widely used for different applications due to its characteristics of compact structure and high energy conversion efficiency. However, the leakage and the friction result in non-negligible energy losses. This paper presents the recent work on developing a new scroll-type air motor with mounted permanent magnetic spirals and investigates its potential in leakage reduction and efficiency improvement, especially at low-pressure air supply conditions. A method for the implementation of the magnetic scroll air motor is proposed. A prototype is manufactured, and initial experimental tests are conducted to study the generalized torque distribution. A mathematical model for the magnetic scroll air motor is developed, and a corresponding simulation study is presented. The study shows that the proposed magnetic scroll air motor structure is feasible in terms of manufacturing and has the potential to reduce the air leakage and, thus, to improve the energy efficiency by a maximum of around 15% at a supply pressure of $2 \times {10^5}$ Pa, with a flank leakage clearance reference of 0.06 mm.

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A New Scroll-Type Air Motor With Magnetic Spirals

A hierarchical structure energy storage (ES) system for photovoltaic (PV) power generation is proposed to make the most use of various kinds of ES devices and reduce cost. The ESs with quick response speed like supercapacitor is used to smooth the variations of PV power; the ESs with large capacity like battery is used to reduce peak and fill valley. The power fluctuations of PV in multiple regions are divided into different frequency segments for stabilization. The system can operate with or without AC grid support. The paper also proposed a protection strategy that adjust the charging or discharging power of the battery in real time with consideration of its state of charge (SOC) and the power limit. The proposed protection strategy ensures the power system security and stability.

Xing Luo

Papers

Control and energy efficiency analysis for a pneumatic-electrical system

A New Scroll-Type Air Motor With Magnetic Spirals

Energy distribution and security control of hierarchical structure energy storage system

Development of a Battery Charging Management Unit for Renewable Power Generation