The electric vehicle (EV) technology addresses the issue of the reduction of carbon and greenhouse gas emissions. The concept of EVs focuses on the utilization of alternative energy resources. However, EV systems currently face challenges in energy storage systems (ESSs) with regard to their safety, size, cost, and overall management issues. In addition, hybridization of ESSs with advanced power electronic technologies has a significant influence on optimal power utilization to lead advanced EV technologies. This paper comprehensively reviews technologies of ESSs, its classifications, characteristics, constructions, electricity conversion, and evaluation processes with advantages and disadvantages for EV applications. Moreover, this paper discusses various classifications of ESS according to their energy formations, composition materials, and techniques on average power delivery over its capacity and overall efficiencies exhibited within their life expectancies. The rigorous review indicates that existing technologies for ESS can be used for EVs, but the optimum use of ESSs for efficient EV energy storage applications has not yet been achieved. This review highlights many factors, challenges, and problems for sustainable development of ESS technologies in next-generation EV applications. Thus, this review will widen the effort toward the development of economic and efficient ESSs with a longer lifetime for future EV uses.

Review of energy storage systems for electric vehicle applications: Issues and challenges

A microgrid (MG) is a local entity that consists of distributed energy resources (DERs) to achieve local power reliability and sustainable energy utilization. The MG concept or renewable energy technologies integrated with energy storage systems (ESS) have gained increasing interest and popularity because it can store energy at off-peak hours and supply energy at peak hours. However, existing ESS technology faces challenges in storing energy due to various issues, such as charging/discharging, safety, reliability, size, cost, life cycle, and overall management. Thus, an advanced ESS is required with regard to capacity, protection, control interface, energy management, and characteristics to enhance the performance of ESS in MG applications. This paper comprehensively reviews the types of ESS technologies, ESS structures along with their configurations, classifications, features, energy conversion, and evaluation process. Moreover, details on the advantages and disadvantages of ESS in MG applications have been analyzed based on the process of energy formations, material selection, power transfer mechanism, capacity, efficiency, and cycle period. Existing reviews critically demonstrate the current technologies for ESS in MG applications. However, the optimum management of ESSs for efficient MG operation remains a challenge in modern power system networks. This review also highlights the key factors, issues, and challenges with possible recommendations for the further development of ESS in future MG applications. All the highlighted insights of this review significantly contribute to the increasing effort toward the development of a cost-effective and efficient ESS model with a prolonged life cycle for sustainable MG implementation.

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Review of Energy Storage System Technologies in Microgrid Applications: Issues and Challenges

Power control strategy and performance evaluation of a novel electro-hydraulic energy-saving system

Electrified vehicles are considered a promising technology for energy savings and emission reductions. Both powertrain design (configuration design and component sizing) and energy management strategies (EMSs) for electrified vehicles have been studied extensively. However, powertrain design and energy management need to be examined holistically and optimized simultaneously, from a mechatronic viewpoint, for maximizing the potential of electrified powertrains. This article provides a comprehensive, critical review of the current state, and prospects of electrified powertrain design and energy management. The research status in both powertrain design and energy management development is reviewed and discussed. First, the modeling techniques for rapid configuration design are thoroughly reviewed and summarized. Then, the optimization methods for component sizing are elucidated. Next, the classical EMSs are categorized, and several near-optimal strategies used for powertrain design are elaborated. Finally, the current challenges and future trends of electrified powertrain design and control are discussed, which provides a useful reference to researchers in this area.

Powertrain Design and Control in Electrified Vehicles: A Critical Review

Flywheel energy storage technology plays an important role in enhancing the operation reliability and efficiency of wind power generation farms. This work investigates an aggregated connection topology of flywheel energy storage matrix system, which is composed of multiple flywheel energy storage system (FESS) units within a wind farm. Based on this architecture, an effective charge/discharge strategy is introduced in order to ensure cooperative operation among flywheels, so as to realize smooth power transients, quality regulation, and voltage restoration. For each FESS unit, a structurally simple and computationally inexpensive neural-adaptive proportional integration derivative (PID) control algorithm based on Lyapunov stability theory is developed to control each flywheel individually in coordinated and stable manner. The merits and benefits of the proposed method are validated and demonstrated by both numerical simulations and experimental results.

Hierarchical Coordinated Control of Flywheel Energy Storage Matrix Systems for Wind Farms

Mechanical hybrid powertrains have the potential to improve the fuel economy of passenger vehicles at a relatively low cost, by adding a flywheel and only mechanical transmission components to a conventional powertrain. This paper presents a systematic approach to optimizing the topology and flywheel size, which are the key design parameters of a mechanical hybrid powertrain. The topology is optimized from a limited set of over 20 existing mechanical hybrid powertrains described in the literature. After a systematic classification of the topologies, a set of four competitive powertrains is selected for further investigation. The fuel-saving potential of each hybrid powertrain is computed using an optimal energy controller and modular component models, for various flywheel sizes and for three certified driving cycles. The hybridization cost is estimated based on the type and size of the components. Other criteria, such as control complexity, clutch wear, and driving comfort are qualitatively evaluated to put the fuel-saving potential and the hybridization cost into a wider perspective. Results show that, for each of the four investigated hybrid powertrains, the fuel-saving benefit returns the hybridization investment well within (about 50%) the service life of passenger vehicles. The optimal topology follows from a discussion that considers all the optimization criteria. The associated optimal flywheel size has an energy storage capacity that is approximately equivalent to the kinetic energy of the vehicle during urban driving (50 km/h).

Sca Rullens

Papers

Topology and Flywheel Size Optimization for Mechanical Hybrid Powertrains

Analysis of optimal mechanical-hybrid powertrain topologies