Hybrid Energy Storage Module Research Articles

Operating characteristics analysis and capacity configuration optimization of wind-solar-hydrogen hybrid multi-energy complementary system

Wind and solar energy are the important renewable energy sources, while their inherent natures of random and intermittent also exert negative effect on the electrical grid connection. As one of multiple energy complementary route by adopting the electrolysis technology, the wind-solar-hydrogen hybrid system contributes to improving green power utilization and reducing its fluctuation. Therefore, the moving average method and the hybrid energy storage module are proposed, which can smooth the wind-solar power generation and enhance the system energy management. Moreover, the optimization of system capacity configuration and the sensitive analysis are implemented by the MATLAB program platform. The results indicate that the 10-min grid-connected volatility is reduced by 38.7% based on the smoothing strategy, and the internal investment return rate can reach 13.67% when the electricity price is 0.04 $/kWh. In addition, the annual coordinated power and cycle proportion of the hybrid energy storage module are 80.5% and 90%, respectively. The developed hybrid energy storage module can well meet the annual coordination requirements, and has lower levelized cost of electricity. This method provides reasonable reference for designing and optimizing the wind-solar-hydrogen complementary system.

Integrated Control Strategy of Voltage and Frequency Modulation for the Photovoltaic-storage Unit

With the increasing installation of new energy power generation, photovoltaic power generation has become a significant component of the power system. However, the random and fluctuating nature of photovoltaic power generation can pose a challenge. The combination of photovoltaic power generation with energy storage using a photovoltaic-storage unit integrated machine can help mitigate the fluctuations of photovoltaic power generation output and improve the power quality of photovoltaic grid connection. In this paper, we propose a grid-connected integrated control strategy for the photovoltaic-storage unit integrated machine. We use a hybrid energy storage module with a lithium battery and a super capacitor as the energy storage unit for the photovoltaic-storage unit integrated machine. Finally, we use the MATLAB/Simulink simulation platform to simulate and verify the effectiveness of our proposed strategy.

A Dynamic and Cooperative Control Strategy for Multi-Hybrid Energy Storage System of DC Microgrid Based on SOC

With the increasingly serious crisis of fossil energy and environmental pollution, clean renewable energy becomes the inevitable choice of energy structure adjustment. The instability of output power of distributed renewable energy system greatly affects the operation of DC microgrid. The hybrid energy storage system (HESS) composed of High-Energy Battery (HEB) and High-Power Battery (HPB) can solve the above problems. Thus, this paper proposes a dynamic and cooperative control strategy for multi-HESS based on state of charge (SOC). Based on the traditional LPF method and droop control, this paper proposes a control strategy that requires no communication among multiple hybrid energy storage (HES) modules. This method can realize the stable control of HEB current, reduce the change times of HEB charging-discharging mode, prevent HEB from overcharging and overdischarging, prolong the service life of HEB and balance different energy storage SOC, so as to improve the operation stability and economy of DC microgrid. In addition, the method has certain robustness against sudden failures. Simulation and experiment results show the effectiveness of the proposed method.

Characterization of Ultracapacitors for Transient Load Applications

Ultracapacitors (UCs) are of increasing interest in different application areas, such as microgrids and transportation, which demand high transient power and are growing in capability every day. New power system architectures have been proposed that may be well suited to reliably and efficiently supply power to these previously unseen applications. Among the architectures that hold a great deal of promise are hybrid energy storage modules that integrate energy dense batteries with power dense UCs into a single power supply that augments traditional generation technologies. Within such architecture, the UC is the element that may be utilized to sink and source power quickly, at the leading or falling edge of a transient event. Considerable advances have been made to increase both the power and energy density, respectively, of UCs. Significant reduction of the internal impedance has resulted in an increased power capability that makes UCs well suited for use in these applications. Hybrid UC technologies, such as lithium-ion capacitors, have been developed, which have much higher energy density with nearly the same power density. In an effort to better understand and validate the capabilities of new UC technologies, a series of experiments has been performed on cells from four different manufacturers. Novel experimental testbeds and methods have been used to measure each technology’s internal impedance and power density. The experimental testbed utilized, along with the results collected to date, will be presented.

Fuzzy logic control of a hybrid energy storage module for use as a high rate prime power supply

Hybrid Energy Storage Modules (HESM) have emerged as a possible energy storage device for naval pulsed power applications [1–6]. A HESM combines energy dense and power dense devices to offer a holistic solution for repetitive loads that are highly transient in nature. Actively controlled power electronic converters are used to regulate the power that flows from each energy storage or generation source to a point of common coupling. In these types of naval applications, it is likely that the system will be comprised of components that are available as commercially off the shelf (COTS) components, though some may be custom designed as well. Combining COTS components in a HESM can be challenging because system-level control must be imposed on top of individual device control. Previous work at the University of Texas at Arlington (UTA) has demonstrated a basic model of a HESM and a fuzzy logic systemlevel controller through software simulation. Building on the work by UTA, this paper will validate a model of a Hybrid Energy Storage Module with fuzzy logic system-level control under the effects of a transient pulsed power load.

Fuzzy Logic Control of A Hybrid Energy Storage Module for Naval Pulsed Power Applications

There is need for an energy storage device capable of transferring high power in transient situations aboard naval vessels. Currently, batteries are used to accomplish this task, but previous research has shown that when utilized at high power rates, these devices deteriorate over time causing a loss in lifespan. It has been shown that a hybrid energy storage configuration is capable of meeting such a demand while reducing the strain placed on individual components. While designing a custom converter capable of controlling the power to and from a battery would be ideal for this application, it can be costly to develop when compared to purchasing commercially available products. Commercially available products offer limited controllability in exchange for their proven performance and lower cost point - often times only allowing a system level control input without any way to interface with low level controls that are frequently used in controller design. This paper proposes the use of fuzzy logic control in order to provide a system level control to the converters responsible for limiting power to and from the battery. A system will be described mathematically, modeled in MATLAB/Simulink, and a fuzzy logic controller will be compared with a typical controller.

Run-Time Management for Multicore Embedded Systems With Energy Harvesting

In this paper, we propose a novel framework for runtime energy and workload management in multicore embedded systems with solar energy harvesting and a periodic hard real-time task set as the workload. Compared with prior work, our framework makes several novel contributions and possesses several advantages, including the following: 1) a semidynamic scheduling heuristic that dynamically adapts to runtime harvested power variations without losing the consistency of periodic tasks; 2) a battery-supercapacitor hybrid energy storage module for more efficient system energy management; 3) a coarse-grained core shutdown heuristic for additional energy saving; 4) energy budget planning and task allocation heuristics with process variation tolerance; 5) a novel dual-speed method specifically designed for periodic tasks to address discrete frequency levels and dynamic voltage/frequency scaling switching overhead at the core level; and 6) an extension to prepare the system for thermal issues arising at runtime during extreme environmental conditions. The experimental studies show that our framework results in a reduction in task miss rate by up to 70% and task miss penalty by up to 65% compared with the best known prior work.

Design and Characterization of an Actively Controlled Hybrid Energy Storage Module for High-Rate Directed Energy Applications

There is considerable need for a mobile, reliable, efficient, and compact prime power supply for a host of applications, including directed energy and electrical grid backup among others. Electrochemical energy storage devices, which possess either high-power density or high-energy density, have been developed recently and are very applicable for use in these applications. The need for both high energy and high power, however, makes the design and implementation of such a prime power supply a nontrivial task. While lithium-ion batteries (LIBs) are available, which possess both high power and energy density, operation at high power reduces their cycle life, decreasing the reliability and increasing the cost of the system when replacement becomes necessary more frequently. One proposed method involves optimally combining high-energy batteries with high-power electric double layer capacitors (EDLCs) using actively controlled power electronics to regulate the current to and from each respective device. In such a scheme, energy can be slowly sourced to and from the batteries, while the capacitors are used to supply or accept the bulk of the current when the demand is high, especially during fast transients. This type of scheme should not only maximize the batteries' cycle life and ensure that both the energy and power required of the load(s) is always available, but will also increase the instantaneous power capabilities of the system, offering a well-rounded solution to sourcing steady and/or transient loads. When augmenting a fossil fuel generator with a hybrid energy storage module (HESM), the HESM has the ability to act as a high-energy reservoir that can harvest energy from the generator when the loads are in short periods of inactivity. This enables the generator to be continuously base loaded, thereby maintaining a high level of efficiency at all times, while theoretically maintaining the required power quality of the main ac bus. At the University of Texas at Arlington (UTA), an actively controlled, high-rate HESM has been constructed to evaluate its performance under the typical load condition presented by directed energy weapons. It has been assembled using LIBs, EDLCs, and commercial off-the-shelf power electronic converters. A discussion about the future of HESMs, the experimental setup at UTA, and the results obtained thus far will be presented here.

Evaluation of a Hybrid Energy Storage Module for Pulsed Power Applications

Before pulsed power systems can be fielded in either mobile or small footprint stationary applications, the prime power source must be optimized for both size and operational efficiency. In large footprint laboratories, prime power supplies are connected to a local utility grid to charge intermediate storage systems. In mobile platforms, alternative energy sources, such as electrochemical batteries or supercapacitors, must be used to backup smaller fossil fuel generators. The prime power source used in a pulsed power system must store high energy, to maximize the number of shots stored, and be able to source high power to recharge the intermediate store as fast as possible. Finding a single electrochemical energy storage device that has the right energy and power density for most applications is nearly impossible. Therefore, usage of batteries, which possess high energy density, along with electrochemical capacitors, which offer high power density, in a hybrid energy storage module (HESM) configuration is a promising way of combining both of these features into a single supply. Usage of this topology reduces the stress on the batteries, thereby prolonging their life, and also increases the instantaneous power capabilities of the system. This paper presents the design and validation of an actively controlled HESM built using commercial off the shelf power electronics and simple control strategies.