Improved Efficiency Management Strategy for Battery-Based Energy Storage Systems

Battery-based energy storage systems are forecasted to have a rapid diffusion in the next future, because they can support the diffusion of renewable energy sources and can offer interesting ancillary services for the distribution grid. Consequently, energy management strategies for batteries and inverters present in storage systems will play a fundamental role in order to guarantee effective energy transfer processes between storage systems and the grid. This paper proposes an efficient management strategy which allows maximizing the overall energy efficiency of grid-connected storage systems taking into account the actual relationship between the efficiency and the charging/discharging power of the storage system. The effectiveness of the strategy is as shown by analysis results, the proposed strategy can allow a remarkable efficiency increase compared with strategies which are not aimed at the efficiency optimization

Energy Conversion and Control of Hydrogen Fuel Cell Based Electric Transport

The research investigates the effective utilization of hydrogen fuel cells in electric transport applications, addressing the challenges associated with power generation, energy storage, and control. By implementing the MPPT Perturb and Observe (P&O) technique, the thesis aims to optimize the power output of the fuel cell system, ensuring maximum efficiency and performance. To enhance the overall energy management of the system, a battery and supercapacitor combination is employed as supplementary energy storage. The thesis dives into the design and control strategies required for the seamless integration of these energy conversion systems. The battery’s SOC is closely regulated based on the fuel cell voltage, allowing for efficient energy utilization and improved system reliability. The findings of this research contribute to the advancement of hydrogen fuel cell based electric transport systems. The utilization of MPPT techniques, combined with the integration of battery and supercapacitor systems, offers a promising approach to optimize energy conversion and control. The proposed strategies can lead to enhanced energy efficiency, extended driving range, and improved reliability for future hydrogen fuel cell-based electric transport applications

Flywheel Energy Storage Systems for Rail

In current non-electrified rail systems there is a significant loss of energy during vehicle braking. The aim of this research has been to investigate the potential benefits of introducing onboard regenerative braking systems to rail vehicles. An overview of energy saving measures proposed within the rail industry is presented along with a review of different energy storage devices and systems developed for both rail and automotive applications. Advanced flywheels have been identified as a candidate energy storage device for rail applications, combining high specific power and energy. In order to assess the potential benefits of energy storage systems in rail vehicles, a computational model of a conventional regional diesel train has been developed. This has been used to define a base level of vehicle performance, and to investigate the effects of energy efficient control strategies focussing on the application of coasting prior to braking. The impact of these measures on both the requirements of an energy storage system and the potential benefits of a hybrid train have been assessed. A detailed study of a range of existing and novel mechanical flywheel transmissions has been performed. The interaction between the flywheel, transmission and vehicle is investigated using a novel application-independent analysis method which has been developed to characterise and compare the performance of different systems. The results of this analysis produce general ‘design tools’ for each flywheel transmission configuration, allowing appropriate system configurations and parameters to be identified for a particular application. More detailed computational models of the best performing systems have been developed and integrated with the conventional regional diesel train model. The performance of proposed flywheel hybrid regional trains has been assessed using realistic component losses and journey profiles, and the fuel saving relative to a conventional train quantified for a range of energy storage capacities and power-train control strategies

Integration of Electric Energy Storage into Power Systems with Renewable Energy Resources

This dissertation investigates the distribution and transmission systems reliability and economic impact of energy storage and renewable energy integration. The reliability and economy evaluation framework is presented. Novel operation strategies of energy storage and renewable energy are proposed. The method for optimizing the energy storage sizing and operation strategy in order to achieve optimal reliability and economy level is developed. The objectives of the movement towards the smart grid include making the power systems more reliable and economically efficient. The rapid development of the large scale energy storage technology makes it an excellent candidate in achieving these goals. A novel Model Predictive Control (MPC)-based operation strategy is proposed to optimally manage the charging and discharging operation of energy storage in order to minimize the energy purchasing cost for a distribution system load aggregator in power markets. Different operation strategies of energy storage have different reliability and economic impact on power systems. Simulation results illustrate the importance of the energy storage operation strategies. A hybrid operation strategy which combines the MPC-based operation strategy and the standby backup operation strategy is proposed to flexibly adjust the reliability and economic improvement brought by energy storage. A particle swarm optimization approach is developed to determine the optimal energy storage sizing and operation strategy while maximizing reliability and economic improvement. A reliability and economy assessment framework based on sequential Monte Carlo method integrated with the operation strategies is proposed. The impact on the transmission systems reliability brought by energy storage and renewable energy with the proposed operation strategies is investigated. Case studies are conducted to demonstrate the effectiveness of the proposed operation strategies, optimization approach, and the reliability and economy evaluation framework. Insights into how energy storage and renewable energy affect power system reliability and economy are obtained

PV Hosting Capacity Analysis and Enhancement Using High Resolution Stochastic Modeling

Reduction of CO2 emissions is a main target in the future smart grid. This goal is boosting the installation of renewable energy resources (RES), as well as a major consumer engagement that seeks for a more efficient utilization of these resources toward the figure of ‘prosumers’. Nevertheless, these resources present an intermittent nature, which requires the presence of an energy storage system and an energy management system (EMS) to ensure an uninterrupted power supply. Moreover, network-related issues might arise due to the increasing power of renewable resources installed in the grid, the storage systems also being capable of contributing to the network stability. However, to assess these future scenarios and test the control strategies, a simulation system is needed. The aim of this paper is to analyze the interaction between residential consumers with high penetration of PV generation and distributed storage and the grid by means of a high temporal resolution simulation scenario based on a stochastic residential load model and PV production records. Results of the model are presented for different PV power rates and storage capacities, as well as a two-level charging strategy as a mechanism for increasing the hosting capacity (HC) of the network

Advanced Statistical Modeling, Forecasting, and Fault Detection in Renewable Energy Systems

Fault detection, control, and forecasting have a vital role in renewable energy systems (Photovoltaics (PV) and wind turbines (WTs)) to improve their productivity, ef?ciency, and safety, and to avoid expensive maintenance. For instance, the main crucial and challenging issue in solar and wind energy production is the volatility of intermittent power generation due mainly to weather conditions. This fact usually limits the integration of PV systems and WTs into the power grid. Hence, accurately forecasting power generation in PV and WTs is of great importance for daily/hourly efficient management of power grid production, delivery, and storage, as well as for decision-making on the energy market. Also, accurate and prompt fault detection and diagnosis strategies are required to improve efficiencies of renewable energy systems, avoid the high cost of maintenance, and reduce risks of fire hazards, which could affect both personnel and installed equipment. This book intends to provide the reader with advanced statistical modeling, forecasting, and fault detection techniques in renewable energy systems

Control Strategy for Distributed Integration of Photovoltaic and Battery Energy Storage System in Micro-Grids

The micro-grid deployments are growing with independently, power system designers, manufacturers and researchers for the applications where the loads are more efficient association with extra output sources such as Battery Energy Storage System (BESS), and Photovoltaic (PV) systems. Using renewable source as main sources for micro-grid system also can avoid from the pollution to occur. Energy storage when combined with PV system can provide a stronger economic performance, as well as an added benefit of backup power for critical loads. This project proposed control strategies for integration of BESS and PV in a micro-grid. The operation enables the maximum PV and BESS utilization during different operating condition of the micro-grid, grid connected, islanded mode or a process between these two operations. The project will focus on analyzing the performance between photovoltaic system and battery in the simulations of micro-grids system and validate the simulation result using MATLAB/SIMULINK software. After the simulation was analyzed, the understanding of benefit in using renewable energy source as main power supply with support from battery energy storage to supply the power to the loads and power managements is realized in the different modes on micro-grid which is grid connected or islanded states. When the power generation from PV system was not enough to accommodate electric loads, the BESS or from secondary side of transformer will supply the insufficient power