Flywheel Energy Storage Device Research Articles

Hybrid energy storage configuration method for wind power microgrid based on EMD decomposition and two-stage robust approach

Data centers are usually characterized by high energy loads, which raises increasing sustainability concerns in both academic and daily usage. To mitigate the uncertainty and high volatility of distributed wind energy generation, this paper proposes a hybrid energy storage allocation strategy by means of the Empirical Mode Decomposition (EMD) technique and the two-stage robust method. First, this paper conducts the evolution analyses for the over- and under-evaluated uncertainty of wind power fluctuation under different time scales. Second, we employ the EMD technique to configure a high-frequency flywheel energy storage device, realizing the wind power transformation from large fluctuations to small fluctuations and the convergence of the wind power fluctuation curves in minute- and hour levels. Finally, based on the hour-level wind energy stable power curves, we carry out two-stage robust planning for the equipment capacity of low-frequency cold storage tanks and lithium bromide chillers. The case study on a data center microgrid in northeastern China confirms the effectiveness of our proposed strategy.

Hybrid energy storage power allocation strategy based on parameter-optimized VMD algorithm for marine micro gas turbine power system

The power system onboard ships is typically a low-inertia, small-capacity isolated grid that is highly susceptible to system disturbances and instability, especially when connected to high power pulse loads. To mitigate power fluctuations and ensure stable operation, a hybrid energy storage system (HESS), which comprises the battery system and flywheel energy storage devices, has emerged as a promising solution. This paper explores the control strategy and coordinated operation of marine gas turbine power generation systems operating under pulse load conditions and presents a novel hybrid energy storage power allocation strategy based on variational mode decomposition (VMD). Specifically, we propose to implement parameter optimization of VMD using an artificial hummingbird algorithm (AHA), which enables effective primary allocation of hybrid energy storage power. To achieve secondary power allocation, we design two fuzzy controllers to optimize the state of charge (SOC) of battery system and speed of flywheel device. To evaluate the feasibility and effectiveness of the proposed control strategy, we establish a theoretical model of a shipboard micro gas turbine (MGT) direct current (DC) power system, which includes an MGT, generator, HESS, and pulse power load. Our simulation results demonstrate that the artificial hummingbird algorithm outperforms the particle swarm algorithm concerning search speed and calculation accuracy for parameter optimization of variational mode decomposition. Moreover, the proposed parameter-optimized VMD method can adaptively decompose pulse load power fluctuations and achieve optimal allocation of the flywheel and battery power in the HESS. Finally, the parallel fuzzy controller design effectively optimizes the operation ranges of the flywheel device and battery system, prevents over-charging and over-discharging of energy storage equipment, ensures that the SOC of energy storage equipment remains within a fixed interval, and reduces frequent and high-power charging and discharging of batteries.

Simulation on modified multi-surface levitation structure of superconducting magnetic bearing for flywheel energy storage system by H-formulation and Taguchi method

Improving the performance of superconducting magnetic bearing (SMB) is very essential problem to heighten the energy storage capacity of flywheel energy storage devices which are built of components such as superconductor bulks, permanent magnets, flywheel, cooling system and so on. In this paper, three surfaces levitation-superconducting magnetic bearing (TSL-SMB) was simulated in two-dimensional axisymmetric system using H-formulation and Taguchi method. The system was worked by field cooling (FC) method. Taguchi-based L32(21×49) mixed orthogonal array was used to formulate the simulation plans for TSL-SMB, and effects of geometric parameters on levitation force in TSL-SMB was considered using Analysis of Variance (ANOVA). In the optimized TSL-SMB structure, there was no good difference whether the effect of concentric ring PMs with opposite polarization was included or not. Therefore, four surfaces levitation-superconducting magnetic bearing (FSL-SMB) as advanced multi-surface levitation system was presented to improve the performance of SMB. The simulation results in the FSL-SMB system showed that the gap between the stator and the rotor and levitation force per permanent magnet volume might be increased more than those of TSL-SMB system in the condition of same load capacity, this will contribute to improve the load capacity of SMB.

Research on Magnetic Coupling Flywheel Energy Storage Device for Vehicles

With the increasing pressure on energy and the environment, vehicle brake energy recovery technology is increasingly focused on reducing energy consumption effectively. Based on the magnetization effect of permanent magnets, this paper presents a novel type of magnetic coupling flywheel energy storage device by combining flywheel energy storage with magnetic coupling technology. As a high-efficiency energy storage device, it has the advantages of low energy consumption, low vibration, low noise and easy maintenance. In this paper, firstly, the structural characteristics and working process of vehicle brake energy recovery systems are analyzed, and experiments regarding the transmission and efficiency performance are carried out for key components; then a reasonable control strategy is formulated according to the principle of energy recovery; finally, the speed, acceleration, recovery energy and other parameters are analyzed based on the New European Driving Cycle (NEDC) working conditions. The results show that the energy recovery efficiency reaches 35.59%, which verifies the usability of the device.

Flywheel energy storage controlled by model predictive control to achieve smooth short-term high-frequency wind power

The use of energy storage systems to improve the fluctuation of wind power generation has garnered significant in the development of wind power. However, the fluctuation of the signals in the high-frequency part of the wind turbine output is particularly drastic and short in duration. As a kind of physical energy storage device, the flywheel energy storage device has a fast response speed but higher requirements on the control system. In order to improve the control effect of the flywheel energy storage device, the model predictive control algorithm is improved in this paper. First, the high-frequency components of the wind farm output power data are extracted by the wavelet packet decomposition algorithm, and the high-frequency components are optimized by mathematical interpolation as the data basis. Secondly, a mathematical model of the flywheel energy storage system applied in the model predictive control algorithm is proposed, and the model predictive control algorithm is used to configure the flywheel energy storage device to achieve a smooth output power of the wind farm. Finally, the simulation is performed in MATLAB and the experimental parameters are adjusted. The experimental results show that the configuration of the flywheel energy storage system based on the model predictive control algorithm can effectively smooth the fluctuation of the high-frequency component of the output power data of the wind farm. The experimental results take the wind power data of different time periods for energy storage configuration, and the comparison verifies the reliability of the system designed in this paper.

Control of braking energy recovery of lifting machines

The increase in the energy consumption of machines when operating in unsteady modes is caused by many reasons, the main of which are deviation from the calculated operating modes and braking of the machine with irretrievable energy losses. When driving cars from electric motors, the recovery of braking energy can be carried out by switching them to the electric generator mode and returning the braking energy to the general power supply network. However, the absence of parallel consumers in the general power supply network requires the presence of an electric energy accumulator to recover braking energy. Effective recovery of braking energy can be carried out in a flywheel energy storage device with a high service life and high specific indicators of stored energy per unit weight of the storage device using differential gear mechanisms having two degrees of freedom.

A novel application of jellyfish search optimisation tuned dual-stage (1 + PI)TID controller for microgrid employing electric vehicle

ABSTRACT The main purpose of this paper is to implement a novel jellyfish search optimisation-based dual-stage (1+ proportional integral) tilt-integral derivative controller in an isolated and two-area renewable energy-based microgrid cluster to achieve stabilisation of frequency and tie-line power in the system. To fulfil this objective, the proposed cluster consists of a dish Stirling solar generator, micro-hydro turbine, diesel generator, flywheel energy storage device, super magnetic energy storage device and electric vehicle. The supremacy of the dual-stage controller over simple proportional integral derivative controller as well as tilt order controllers such as tilt integral derivative filter double integral and tilt integral tilt derivative with filter is demonstrated. The performance of the jellyfish search optimisation-based dual-stage controller is also compared with the black widow optimisation algorithm, genetic algorithm and particle swarm optimisation-based controller with respect to overshoot, undershoot, settling time and figure of demerit. In addition to this, a sensitivity analysis has been executed by changing the system parameters in the range of ±20% from its nominal value. Lastly, an effort is made to assess the impact of controllable load i.e. electric vehicle with the proposed controller in isolated microgrid.

A Review of Superconducting Magnetic Bearings and Their Application

Magnetic bearings are being researched for high-speed applications, such as flywheel energy storage devices, to eliminate friction losses. As per Earnshaw's theorem, stable levitation cannot be achieved for a static passive magnetic bearing system. Fully passive stable levitation can be achieved with the help of superconducting magnetic bearings (SMB). This article provides an in-depth review of the modeling, analysis, and development of SMB. The different SMB configurations are highlighted, together with essential methodologies for estimating and improving their performance. The advancements in mathematical models used and the optimization of bearing characteristics are thoroughly discussed. Further, key developments in the application of SMB in flywheel energy storage systems are also reviewed.

Control technology and development status of flywheel energy storage system

Flywheel energy storage technology has attracted more and more attention in the energy storage industry due to its high energy density, fast charge and discharge speed, long service life, clean and pollution-free characteristics. It is wwidely used in uninterruptible power system, grid frequency modulation, energy recovery and reuse and other fields. With the development of flywheel rotor materials, motors, bearings and control technology, flywheel energy storage technology has been greatly developed. Introducing the basic structure of the flywheel energy storage system in the above three applications. Typical charge-discharge control strategies are given for the three sensor-less algorithms of model reference adaptive control, sliding mode observer andextended Kalman filter, which are suitable for flywheel energy storage devices.

Primary Frequency Support in Unit Commitment Using a Multi-Area Frequency Model With Flywheel Energy Storage

In this paper, a Frequency Stability Constrained Unit Commitment (FSCUC) model is presented. The on/off status of generating units, generation levels and operating reserves are optimized to minimize the operational daily costs. The frequency stability constraints are included in the proposed FSCUC model to guarantee the safety of System Frequency Response (SFR) under sudden generation outages. A new multi-area SFR model is proposed to capture the regional dynamics of system frequency with considering the impacts of transmission network. An SFR model is developed for each electric region and then the resulted regional SFRs are coupled via a set of constraints. In order to enhance the primary SFR and keep the daily operating point at its economic schedule, Flywheel Energy Storage (FES) devices are utilized in the proposed FSCUC model. The proposed multi-area SFR model allows the optimal allocation of operating reserve and the accurate modeling of FESs in FSCUC model. The proposed FSCUC model is formulated as a Mixed Integer Linear Programming (MILP) problem and is applied over the IEEE 118-bus test system to show the accuracy of the proposed multi-region SFR and the impact of FES in frequency support. The developed MILP model is solved using CPLEX in GAMS.

Load frequency control of a m ulti‐source multi‐area thermal system including biogas–solar thermal along with pumped hydro energy storage system using MBA ‐optimized 3DOF‐TIDN controller

In this article, load frequency control has been studied in an unequal three-area system under a deregulated environment. The area 1 comprises thermal and biodiesel units, area 2 has thermal and solar thermal power plant (STPP), and area 3 has thermal with biogas, wind turbine system (WTS) along with pumped hydro energy storage (PHES) units. A new secondary controller called three degree-of-freedom tilt-integral-derivative with filter (3DOF-TIDN) controller has been proposed, and its performance is compared with integral, tilt-integral-derivative with filter, and two degree-of-freedom-TIDN controllers. The investigation reveals 3DOF-TIDN controller provides better dynamic performance in terms of settling time, peak deviation, and magnitude of oscillations in both generating and motoring mode of PHES. The stability analysis has been performed for the proposed system using different secondary controller. The controller parameters are optimized using novel optimization technique called Mine Blasting Algorithm. In this study, real-time OPAL-RT digital simulator has been used to effectually execute the considered power system under various scenarios, and the obtained results are compared with MATLAB/Simulink results. Further, a comparative study of dynamic responses of the system has been carried out considering different mechanical energy storage devices like PHES, flywheel energy storage device, and compressed air energy storage, and the analysis shows that PHES gives superior performances than others. Robustness analysis of proposed controller gains is also conducted, considering different uncertainties.

Effects of Viscoelasticity on the Stress Evolution over the Lifetime of Filament-Wound Composite Flywheel Rotors for Energy Storage

High-velocity and long-lifetime operating conditions of modern high-speed energy storage flywheel rotors may create the necessary conditions for failure modes not included in current quasi-static failure analyses. In the present study, a computational algorithm based on an accepted analytical model was developed to investigate the viscoelastic behavior of carbon fiber reinforced polymer composite flywheel rotors with an aluminum hub assembled via a press-fit. The Tsai-Wu failure criterion was applied to assess failure. Two simulation cases were developed to explore the effects of viscoelasticity on composite flywheel rotors, i.e., a worst-case operating condition and a case akin to realistic flywheel operations. The simulations indicate that viscoelastic effects are likely to reduce peak stresses in the composite rim over time. However, viscoelasticity also affects stresses in the hub and the hub-rim interface in ways that may cause rotor failure. It was further found that charge-discharge cycles of the flywheel energy storage device may create significant fatigue loading conditions. It was therefore concluded that the design of composite flywheel rotors should include viscoelastic and fatigue analyses to ensure safe operation.

Performance test of flywheel energy storage device

Performance test of flywheel energy storage device

Development of eco-friendly mechanized rotary parking lots with a flywheel energy storage device

Perspective type of mechanized parkings is a multi-storey rotary parking system. It is the most efficiency type, but it costs relatively high per unit of parking space. Lower speed of transportation of cars in comparison with other parking types slightly influences on productivity, because an efficiency of work of the device is firstly defined by duration of stages of loading and unloading of cars. The main disadvantage of multi-storey car parks compared to conventional parking lots - is the need for increasing costs for the operation of the lifting device. One of the methods of improving the energy efficiency of lifting and transport machines is the development of structures with energy recuperation. It allows the kinetic energy of the moving parts at the stage of braking to be accumulated in the battery, and to get used for acceleration when performing the next movement. The article describes the mechanism of a rotary-type parking lot with a flywheel energy storage device, and its principle of operation. The characteristics of a flywheel energy accumulator are well suited to the task. In terms of the specific energy reserve per unit of weight, the flywheel battery effectively competes with the electric one, differing from it by a higher working life. Also, its properties do not deteriorate at low operating temperatures. The justification of the choice of the required parameters of the flywheel, the analysis of its shape and the choice of material from which the flywheel can be made.

The Influence of the Solar Flywheel Energy Storage Control System Based on the Improved Disturbance Observation Method on the Improvement of New Energy Efficiency

The purpose of this study was to improve the utilization efficiency of solar energy, and accelerate the innovation and development of solar flywheel energy storage control system, so as to enhance the utilization value of new energy. Firstly, the definition and working method of flywheel energy storage control system were described, and the characteristics of flywheel energy storage control system were introduced in detail. Secondly, the concept and working principle of solar flywheel energy storage control system were introduced, and the principle and calculation method of perturbation and observation method (P&O) were described in detail. Finally, the improved P&O based on particle swarm optimization (PSO) algorithm was described in detail, and its principle and operation methods were explained. The research results show that the biggest characteristic of flywheel energy storage device is that it has no pollution to the environment, the energy stored per unit area is large, and the efficiency of converting it into electric energy is very high, which can be used for a long time. The working property of solar energy storage system is the introduction, maintenance, and output of electric energy. In order to obtain the best tracking data, the flywheel energy storage control system must control the disturbance amplitude and time accurately and make a comprehensive choice. The P&O improved by PSO algorithm is applied to the flywheel energy storage control system, and the experience time to reach the maximum efficiency position is relatively shortened. When the system’s derived power reaches the balance, the variation of wave shape in the improved dynamic observation method is also relatively reduced.

Robust Mixed H 2 / H ∞ Controller Design for Energy Routers in Energy Internet

In this paper, a class of mixed H 2 / H ∞ controller is designed for an energy router (ER) within the scenario of an energy Internet (EI). The considered ER is assumed to have access with photovoltaic panels, wind turbine generators, micro-turbines, fuel cells, diesel engine generators, battery energy storage devices, flywheel energy storage devices, loads, and other ERs. Two types of control targets are considered. First, due to the access of large-scale renewable energy sources, the DC bus voltage deviation within the ER system shall be regulated. Second, an optimal energy management strategy shall be achieved, such that the autonomous power supply-demand balance within each ER is achieved with priority and the rational utilization of controllable power generation devices and energy storage devices are realized. When these objectives are considered simultaneously, the control issues with respect to ER is formulated as a mixed robust H 2 / H ∞ control problem with analytical solutions provided. Several numerical examples are given, and the feasibility and effectiveness of the proposed method are demonstrated.

Guest editorial - Electric machines in renewable energy applications

The main objective of this special issue is to collect and disseminate publications that highlight recent advances and breakthroughs in the area of renewable energy resources. The use of these resources for production of electricity is increasing rapidly worldwide. As of 2015, a majority of countries have set renewable electricity targets in the 10%–40% range to be achieved by 2020–2030, with a few notable exceptions aiming for 100% generation by renewables. We are experiencing a truly unprecedented transition away from fossil fuels, driven by environmental, energy security, and socio-economic factors.Electric machines can be found in a wide range of renewable energy applications, such as wind turbines, hydropower and hydrokinetic systems, flywheel energy storage devices, and low-power energy harvesting systems. Hence, the design of reliable, efficient, cost-effective, and controllable electric machines is crucial in enabling even higher penetrations of renewable energy systems in the smart grid of the future. In addition, power electronic converter design and control is critical, as they provide essential controllability, flexibility, grid interface, and integration functions.

영구자석의 반발력과 코리올리 효과를 이용한 트로이덜 형 자이로의 설계

This paper deals with the design of 1-kW troidal type gyro. In general, gyro can be used as magnet bearing or flywheel energy storage device. The proposed troidal type gyro is used as a flywheel energy storage device. The gyro is capable of high-speed rotation in the air. The coriolis effect is taken into account when designing the rotor of the proposed gyro. Also the repulsive power of the permanent magnet is considered while selecting the shape and the thickness of the magnet. The neodymium is used as material of the magnets in this paper. The number of magnets are selected accordingly to reduce these torque ripples because torque ripples is an important factor while designing the gyro. The designed troidal type gyro is verified through the Finite Element Method (FEM).

Optimisation of flywheel energy storage systems with geared transmission for hybrid vehicles

Flywheel energy storage devices may be coupled to mechanical transmissions for braking energy recovery and the provision of additional power for acceleration in hybrid vehicles. Power transmission across a continuous range of speed ratios is necessary. The flywheel size and depth-of-discharge must be chosen for a particular application, and this has a direct effect on transmission efficiency, required gearing ratios and mass of components. Optimisation of these parameters requires a fundamental understanding of this interaction, which has not previously been investigated and reported. To address this, the current paper presents a new method of analysing mechanical flywheel systems. A simple algebraic analysis can be used to specify flywheel system parameters for any regenerative braking application where the flywheel is used to provide initial acceleration of the vehicle from stationary. This has been applied to systems using geared transmissions with continuous speed variation achieved through sliding contact in clutch and brake components. The results of the analysis highlight how the optimum selection of flywheel depth-of-discharge must achieve a balance between high transmission efficiency and low system mass. This is illustrated for a passenger car application, allowing a full assessment of system performance and the specification of appropriate design parameters.

Performance Prediction of Inertial Auto-Reinforce Magnetic Flywheel Energy Storage Device Using Finite Element Magnetic Modeling

A new feature for flywheel energy storage device is proposed considering the deficiencies in former technology. This feature is introduced as auto-reinforce performance which means giving-back the kinetic energy for flywheel after speed-down occurred (as result of sudden loading). Auto-reinforce performance is an ability to recover the kinetic rotational energy which significantly keeps longer the stored energy of a flywheel device. This novel concept of flywheel is engineered by installing a number of Permanent Magnets (PM) in certain mounting. Hence, the magnetism configuration such magnetic strength, magnetic energy density, pole direction, geometry, and dimension are influential parameters to the mechanical performance. By practicing Finite Element Magnetic Modeling (FEMM), it is possible to predict some designed mechanical parameters such magnetic force and magnetic torque. Finally by evaluating these mechanical parameters, the key performance of this device such as percentage of energy reinforcement and percentage of discharge elongation can be predicted. The main ideas of this paper are: 1) presenting the development stages especially in design prediction using Finite Element Analysis (FEA) software; and 2) discovering the correlation of designed magnetic properties and mechanical parameters for prototyping references.