Supercapacitor Hybrid Energy Storage System Research Articles

Data-based power management control for battery supercapacitor hybrid energy storage system in solar DC-microgrid.

This paper addresses the energy management control problem of solar power generation system by using the data-driven method. The battery-supercapacitor hybrid energy storage system is considered to smooth the power fluctuation. A new model-free control method is utilized in the stand-alone photovoltaic DC-microgrid to provide the power to meet the demand load, while guaranteeing the DC bus voltage is stable. Furthermore, the proposed data-based power management control strategy only needs I/O data. Numerical simulations with real data verify the effectiveness of the proposed method.

Optimal power-split of hybrid energy storage system using Pontryagin’s minimum principle and deep reinforcement learning approach for electric vehicle application

The battery supercapacitor hybrid energy storage system (HESS) based electric vehicles (EVs) require an efficient online energy management system (EMS) to enhance the battery life. The indirect optimal control method, like Pontryagin’s minimum principle (PMP), is gaining attention for its inherent instantaneous optimization and computational simplicity. However, determining the costate, non-casual variable of PMP for a given driving scenario is challenging and significantly affects the optimal solution of minimizing the battery degradation. In this study, we propose an online hybrid EMS by combining PMP and deep reinforcement learning (RL) to precisely predict the optimal costate and simultaneously minimize the battery degradation in a battery supercapacitor HESS assisted EV. Also, we propose an analytical approach to estimate the initial costate to create the costate action space of RL, which could also be used to estimate the initial costate guess for similar applications. We validate the performance of the proposed EMS under driving cycle uncertainties and untrained driving cycles via simulation. The results demonstrate the effectiveness of deep RL for optimal costate estimation to satisfy the charge sustainability of the supercapacitor. The predicted costate maintains the supercapacitor state-of-charge in the desired range while minimizing battery current for uncertain driving profiles. Further, we have compared the battery energy depletion in the proposed EMS and an offline optimal EMS to study the feasibility of the proposed intelligent EMS. The proposed EMS outperforms the offline EMS, achieving a significant improvement of 900 charge–discharge cycles.

Hybrid energy storage system and management strategy for motor drive with high torque overload

The demand for small-size motors with large output torque in fields such as mobile robotics is increasing, necessitating mobile power systems with greater output power and current within a specific volume and weight. However, conventional mobile power sources like lithium batteries face challenges in surpassing the dual limitations of weight and output power due to constraints imposed by materials and other factors. Therefore, this paper references the approach of high-power hybrid energy systems in automobiles and proposes a battery–supercapacitor hybrid energy storage system (BSHESS) and energy management strategy. The motor is powered by the battery during low torque operating conditions, while the additional output power of the battery is used to charge the supercapacitor. In cases of torque overload, the rapid discharge of the supercapacitor provides the motor with a high current, ensuring instantaneous high output power. Furthermore, the proposed energy management strategy is used to control the charging and discharging processes of the supercapacitor, guaranteeing that the charging process of the supercapacitor does not interfere with the battery’s power supply to the motor, as well as maintaining controllability and stability of the current in the discharge process. The feasibility of the principle is verified through simulations, and we also design a complete prototype of the proposed BSHESS and conduct experiments on the motor. The results demonstrate that the maximum output current to the motor is increased by 150% compared to the original level, and the weight is reduced by 64.7% compared to a pure battery-powered system with same maximum current output. Additionally, the energy management strategy enables a more stable charging and discharging process compared to the unmanaged state.

Economic Analysis of Li-Ion Battery–Supercapacitor Hybrid Energy Storage System Considering Multitype Frequency Response Benefits in Power Systems

With the promotion of carbon peaking and carbon neutrality goals and the construction of renewable-dominated electric power systems, renewable energy will become the main power source of power systems in China. Therefore, ensuring frequency stability and system security will emerge as pivotal challenges in the future development process. Created by combining a Li-ion battery and a supercapacitor, a hybrid energy storage system (HESS), which possesses robust power regulation capabilities and rapid response capabilities, holds promise for supporting the frequency stability of power systems. In this context, the assessment of the economic viability of HESSs providing multitype frequency response services becomes a critical factor in their deployment and promotion. In this paper, an economic analysis approach for a Li-ion battery–supercapacitor HESS towards a multitype frequency response is presented. First, a multitype frequency response-oriented operational mode for the HESS is designed, outlining the roles and functions of the Li-ion battery and the supercapacitor in delivering distinct services. Moreover, building upon the analysis of the power trajectory of Li-ion batteries, a lifetime model for the HESS is proposed based on the rain-flow counting method. Furthermore, considering the competitive landscape for the HESS in the frequency regulation ancillary service market, a full lifecycle economic assessment model is proposed. Finally, case studies on actual power system frequency data and PJM market data are performed to verify the effectiveness of the proposed method, and the simulation results confirm that the HESS exhibits robust performance and a competitive advantage in providing multitype frequency response services. Additionally, it demonstrates commendable economic benefits, establishing its potential as a valuable contributor to frequency response services.

CAES-SC hybrid energy storage: Dynamic characteristics and control via discharge process

Energy storage is an effective means to increase renewable energy utilization. Compressed air energy storage (CAES) and super-capacitor (SC) hybrid energy storage system is one of the potential options for renewable energy microgrids due to its low-cost and flexible response capacity. In this paper, we thoroughly investigate the dynamical characteristics of the CAES system and the dynamical interactions between different subsystems in the CAES-SC hybrid energy storage via the discharge process. Dynamical models have been developed for the CAES discharge subsystem and the SC subsystem. Studies of the start-up process of CAES discharge subsystems have shown that the no-load start-up mode is more efficient than the variable-load start-up mode if the equivalent power generation for the same compressed air mass consumption is measured. In terms of the interaction characteristics between the CAES subsystem and the SC subsystem, the capacity demand of the SC subsystem in the no-load start-up mode is about 8 % higher than that in the variable-load start-up mode. An optimal control strategy based on the constraint of source-load dynamic balance has also been proposed to achieve power allocation in a CAES-SC hybrid energy storage system. Case studies show that the cycle efficiency of the hybrid energy storage system corresponding to the proposed optimal control strategy is 57.91 %, which is 1.84 % higher than that of the conventional control strategy. Moreover, compared with the conventional design that takes twice the maximum energy storage capacity demand during the starting process of the CAES discharge subsystem (about 1.6 MWh), a higher designed energy storage capacity (about 3 MWh) of the SC subsystem is required to satisfy the complete response to the source-load deviation under the proposed optimal control strategy. Moreover, for every 0.5 MWh increase in the energy storage capacity of the SC subsystem, the cycle efficiency of the hybrid energy storage system can be increased by approximately 0.3 % to 0.5 %.

Sizing Optimization of a Photovoltaic Hybrid Energy Storage System Based on Long Time-Series Simulation Considering Battery Life

An energy storage system works in sync with a photovoltaic system to effectively alleviate the intermittency in the photovoltaic output. Owing to its high power density and long life, supercapacitors make the battery–supercapacitor hybrid energy storage system (HESS) a good solution. This study considers the particularity of annual illumination due to climate conditions in Harbin, China. A global optimal PV-HESS sizing method is proposed by constructing a PV-HESS operating cost model and taking the annual system operating cost as the objective function. To consider the effect of battery life degradation due to different charge and discharge rates and charge and discharge times, a semi-empirical model based on the Arrhenius model was used to quantify the battery life degradation. Based on the effects of different seasons and different photovoltaic panel sizes, batteries, and supercapacitors on the optimization results, four scenarios are proposed. The feasibility of the system configuration corresponding to the four scenarios is discussed, and an optimal sizing configuration of the system is obtained. The simulation results show that the proposed method can effectively balance the degradation of the ESS due to irregular charging and discharging and determine the minimum operating cost and a reasonable sizing configuration of the system.

A New Model Predictive Current Control Strategy for Hybrid Energy Storage System Considering the SOC of the Supercapacitor

Proportional-integral (PI) control and model predictive control (MPC) are mainly utilized in battery and supercapacitor (SC) hybrid energy storage system (HESS) of dc microgrid. Unfortunately, the regulation time of the PI controller is long, while large current ripples are introduced by MPC when the system frequency is low. This article proposes a new model predictive current control (new MPCC) strategy for HESS based on MPC and PI controllers. This method reduces current ripples, and meanwhile, enhances system stability and rapidity. MPC is adopted as the outer loop and it calculates reference values for the inner PI current loop. Furthermore, the state of charge (SOC) of the SC is considered based on fuzzy control to optimize the reference power of the SC inner controller. First, the topology and mathematical model of HESS in the dc microgrid are analyzed. Then based on PI control and MPC, the new MPCC is proposed, and compared with MPC and PI methods, respectively. Finally, the fuzzy control method takes SOC of SC into account to optimize the SC reference current. Simulation and experimental results show that the proposed new control strategy could effectively decrease current ripples and dynamic processes and entirely perform the high energy density characteristic of batteries and high power density characteristic of SC.

Large-Signal Stabilization Method for Islanded DC Microgrids Considering Battery and Supercapacitor Hybrid Energy Storage Systems

Islanded DC microgrids composed of distributed generators (DGs), constant power loads (CPLs), parallel converters, batteries and supercapacitors (SCs) are typical nonlinear systems, and guaranteeing large-signal stability is a key issue. In this paper, the nonlinear model of a DC microgrid with a hybrid energy storage system (HESS) is established, and large-signal stability criteria are obtained. The HESS consists of batteries and SCs. The derived criteria reveal the influences of the filter parameters, CPL power, DG power and the proportional control parameters of the battery converter and the SC converter on the system large-signal stability. Furthermore, important large-signal stabilization methods for regulating the HESS converter’s control parameters can easily achieve the large-signal stabilization of islanded DC microgrids without extra equipment. The paper is summarized as follows: First, the topology of and control strategy for a DC microgrid with an HESS and CPLs are proposed. Then, according to the characteristics of the HESS, the DGs and the CPLs, the system is equivalently simplified. Finally, the nonlinear model and large-signal stability criteria are both derived using the mixed potential theory, and a large-signal stabilization design method for the HESS converter’s control parameters is proposed. The experimental and simulation results show the effectiveness of the proposed large-signal stabilization method.

A Survey of Battery–Supercapacitor Hybrid Energy Storage Systems: Concept, Topology, Control and Application

A hybrid energy-storage system (HESS), which fully utilizes the durability of energy-oriented storage devices and the rapidity of power-oriented storage devices, is an efficient solution to managing energy and power legitimately and symmetrically. Hence, research into these systems is drawing more attention with substantial findings. A battery–supercapacitor hybrid energy-storage system (BS-HESS) is widely adopted in the fields of renewable energy integration, smart- and micro-grids, energy integration systems, etc. Focusing on the BS-HESS, in this work we present a comprehensive survey including technologies of the battery management system (BMS), power conversion system (PCS), energy management system (EMS), predictive control techniques of the underlying system, application and cost-effective feasibility aspects, etc. This work reflects strong symmetry on different aspects of designing an HESS, and provides guidelines and design references for the research and application of an HESS.

Capacity Sizing of Embedded Control Battery–Supercapacitor Hybrid Energy Storage System

A battery–supercapacitor hybrid energy storage system is investigated as a solution to reduce the high-power delivery stress on the battery. An optimally-sized system can further enhance the storage and cost efficiency. This paper discusses several possible problems in the sizing of a battery–supercapacitor hybrid energy storage system for practical applications. A sizing method that utilises data collected from a fully active embedded control hybrid energy system is proposed. The feasibility of the method is then tested on three load profiles that represent the load demand of inter- and intra-applications with a battery–supercapacitor hybrid energy storage system. The result is compared to a battery-only single energy storage system. The results verified that the number of batteries required in the hybrid energy storage system is reduced by at least 50% compared to the battery-only single energy storage system.

Optimization of Solar Hybrid Power Generation Using Conductance-Fuzzy Dual-Mode Control Method

The functioning of a solar hybrid power system is investigated in this research using a unique fuzzy control method. Turbines, solar photovoltaics, diesel engines, fuel cells, aqua-electrolyzes, and other autonomous generation products are used in the hybrid renewable energy system. Further energy storage components of the system include the batteries, turbine, and ultracapacitor. This research incorporates a supercapacitor hybrid energy storage system (HESS) into a solar hybrid power generating system, allowing the consumption and energy storage space and power output to be significantly increased. This study’s approach incorporates a decentralized power generation system with a HESS while increasing electrical output in phases utilizing a dynamic reactive power compensation scheme and a conductance-fuzzy dual-mode control strategy. Due to a nonlinear behavior of photovoltaic (PV) devices’ power output, maximum power point tracking (MPPT) methods must be used to create the greatest power. Infrequently developing atmospheric circumstances, traditional MPPT algorithms do not work adequately. Modeling is used to determine the microgrid’s power output to the photovoltaic hybrid power generating organization, as well as the optimization method for each device in the network. The dynamic power factor correction scheme and also the conductance-fuzzy dual-mode control approach are primarily used in this study to optimize the solar hybrid renewable energy system.

A Novel Multiport DC-DC Converter for Enhancing the Design and Performance of Battery–Supercapacitor Hybrid Energy Storage Systems for Unmanned Aerial Vehicles

This paper proposes an integrated multiport non-isolated DC–DC converter system for integrating battery–supercapacitor hybrid energy storage with photovoltaics for solar-powered unmanned aerial vehicles applications. Compared to the traditional topologies used, the proposed converter allows a size reduction of at least 20% of the supercapacitor by maximizing the utilization of the rated energy capacity. In addition, by proposing to use a phase-shifted carrier modulation technique, the inductors’ current ripple is reduced, which enables a further reduction in the inductor size. These improvements in capability and performance of the proposed topology are experimentally validated on a 500 W PV/battery–supercapacitor integrated power system prototype.

Study of power management of standalone DC microgrids with battery supercapacitor hybrid energy storage system

<p>In the last years, renewable energy (RE) is increasing widely in the energy sector, and microgrid technology is overgrowing. In this paper, stand-alone microgrid using solar photovoltaic (PV) energy as a source of renewable energy is simulated to provide power for direct current (DC) loads with hybrid energy storage system (HESS) which consists of battery and supercapacitor bank. The proposed microgrid system is tested under various cases of load and variable irradiance to confirm and validate the proposed management strategy to remain the DC bus voltage within a stable limit. The performance of DC microgrid is comparing with and without supercapacitor (SC) bank and notes a desirable decrease in the magnitude of transient voltage when using HESS. The sun power SPR-E19-320 standard was simulated to analyze system performance taking into account the constant load demand. Note that HESS helps reduce transient of DC voltage very effectively in all situations. Very large transients arise due to sudden changes in load demand is also compensated by HESS. The results obtained indicate that the stand-alone DC microgrid with HESS is very beneficial for reducing transient of DC-link voltage that occurs due to sudden change in load or fault. The proposed system is performed by MATLAB/Simulink environment.</p>

Parameter Matching Methods for Li Battery–Supercapacitor Hybrid Energy Storage Systems in Electric Buses

The parameter matching of composite energy storage systems will affect the realization of control strategy. In this study, the effective energy and power utilizations of an energy storage source were defined. With the miniaturization of a composite energy storage system as the optimization goal, the linear programming simplex method was employed to obtain the optimized masses of Li batteries and supercapacitors under the constraints of maximum speed, climbing gradient, acceleration time and cost-effectiveness. As the module numbers shall be integers, the matching results were modified in combination with the graphical method. Owing to the influences of parameter matching schemes on the overall performance and battery life, the critical points of constraints were analyzed and the most appropriate matching numerical points of the composite energy storage system were identified. Simulation and experimental analysis were conducted under practical urban road conditions in China. The results show that the proposed matching method delivers accurate results. Compared with conventional electric buses, the mileage and overall performance of the prototype bus are improved.

On the implementation of hybrid energy storage for range and battery life extension of an electrified Tuk-Tuk

In the pathway towards the transformation of the global energy sector, electric vehicles have gained a sparkling interest owing to their ceased emissions. However, range anxiety and fast battery degradation are the most prominent deficiencies of electric vehicles, and many solutions have been proposed to surmount them. However, such solutions often contribute to additional weight, space, and cost. In this paper, we propose a battery supercapacitor hybrid energy storage system (HESS) with a novel Kalman filtration-based energy management system to preserve the battery state of charge (SoC) enabling longer range and a flattened battery state of health (SOH) function thus enabling longer battery life. The simulation results of the solution have been experimentally verified using a full-scale electrified Tuk-Tuk, i.e., an e-Wheeler. The experimental simulation results are in well agreement with the computer simulation studies. The results show a 6% improvement in the SoC and 0.005% reduction in SOH gradient on a typical Sri Lankan urban Tuk-Tuk drive cycle without compromising the performance.

Implementation of a predictive energy management strategy for battery and supercapacitor hybrid energy storage systems of pure electric vehicles1

Hybrid energy storage system supplies a feasible solution to battery peak current reduction by introducing supercapacitor as auxiliary energy source. Energy management control strategy is a key technology for guaranteeing performance. In this paper, we describe a predictive energy management strategy for battery and supercapacitor hybrid energy storage systems of pure electric vehicles. To utilize the supercapacitor reasonably, Markov chain model is proposed to predict the future load power during a driving cycle. The predictive results are subsequently used by power distribution strategy, which is designed using a low-pass filter and a fuzzy logic controller. The strategy model is developed under MATLAB/Simulink software environment. To validate the performance of the proposed control strategy, a comparison test is implemented based on a 72 V rated voltage hybrid energy storage system experimental platform. The results indicate that the battery peak currents by proposed predictive control strategy are reduced by 26.32%, 28.21% and 27.12% under the UDDS, SC03 and NEDC three driving cycles respectively.

Accurate modelling and analysis of battery–supercapacitor hybrid energy storage system in DC microgrid systems

Accurate modelling and analysis of battery–supercapacitor hybrid energy storage system in DC microgrid systems

Supercapacitor hybrid energy storage system applied to photovoltaic power generation

In order to solve the problem of power pulsation at the DC bus side caused by uneven illumination or load fluctuation, a hybrid energy storage system for supercapacitors is proposed. In the hybrid energy storage circuit, inductors are added to form a high-frequency filter with the supercapacitor, and the supercapacitor absorbs the high-frequency current component of the DC side. The traditional droop control strategy is adopted to effectively filter the high-frequency current component of the battery side, and the battery is responsible for processing the low-frequency current component. The simulation results show that the proposed hybrid energy storage system can reduce the voltage pulsation of the DC bus, and the response and recovery speed is faster, which can effectively suppress the power pulsation on the side of the photovoltaic DC bus.

Optimal Energy Management of Battery Supercapacitor aided Solar PV Powered Agricultural Feed Mill using Pontryagin's Minimum Principle

The commercialization of renewable energy sources is often obstructed due to the cost of energy storages such as batteries, which are unavoidable due to intermittent nature of these energy sources. Average power density and low cycle life of batteries lead to frequent replacement and put additional economic burden toward the replacement cost at its end-of-life. The battery supercapacitor-hybrid energy storage system (BS-HESS) with efficient energy management system (EMS) has shown the potential to improve the battery life in various applications. Here, we exploit the Pontryagin's minimum principle (PMP) for optimal power-split between battery and supercapacitor in HESS for a stand-alone photovoltaic assisted agricultural feed mill such that the battery life is improved. Also, we employ a new technique called hybrid maximum power point tracking, by introducing an extra term in the performance index, to take care of the effects of partial shading and provide fast response to sudden change in solar irradiance. We verify the effectiveness of the proposed PMP-based EMS via simulation and comparison with conventional methods. Simulation results show that the HESS along with PMP-based EMS can improve the battery cycle life compared to rule-based EMS and battery-only storage. Finally, we implement the proposed PMP-based EMS in hardware prototype to prove its practicality. The results obtained are satisfactory.

An Energy Storage Performance Improvement Model for Grid-Connected Wind-Solar Hybrid Energy Storage System.

This study introduces a supercapacitor hybrid energy storage system in a wind-solar hybrid power generation system, which can remarkably increase the energy storage capacity and output power of the system. In the specific solution, this study combines the distributed power generation system and the hybrid energy storage system, while using the static reactive power compensation system and the conductance-fuzzy dual-mode control method to increase output power in stages. At the same time, the optimal configuration model of the wind-solar hybrid power generation system is established using MATLAB/Simulink software. The output power of the microgrid to the wind-photovoltaic hybrid power generation system is calculated by simulation, and the optimization process of each component of the system is simulated. This study mainly uses the static reactive power compensation system and the conductance-fuzzy dual-mode control method to optimize the wind-solar hybrid power generation system. Using MATLAB software simulation verifies the feasibility and rationality of the optimal configuration of the system.