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A significant part of an automobile is the gear box (tractor) casing. The primary objective of using the Gearbox casing is to embrace and allow the transmission of the Gearbox. The Gearbox is a mechanism that regulates speed or torque between the flywheel and the differential. The main shaft and lay shaft with gears equipped embraces the gear box. This paper deals with the modeling and study as an alternative material of the gear box casing for a tractor with E-Glass. Through the development of the simulation software platform ANSYS, it is analyzed statically with different design parameters such as web thickness, gear box housing depth and gear box housing thickness. In order to determine the stress produced and deformation degree, the gear box with traditional Grey cast iron is analyzed; it is then compared with the housing of the E-Glass Gear box. The outcome will be studied and evaluated after study, various combinations of design parameters were used to achieve the design that minimum output in failure at higher load s has better deformation characteristics. Finally, in order to design the gear box housing, an optimized design parameter is obtained.[1]

The popularity of the eBus has been increasing rapidly in recent years due to its low greenhouse gases (GHG) emissions and its low dependence on fossil fuels. This incremental use of the eBus increases the burden to the power grid for its charging. Charging eBus requires a high amount of power for a feasible amount of time. Therefore, developing a fast-charging station (FCS) integrated with Micro Energy Grid (MEG) and hybrid energy storage is crucial for charging eBuses. This paper presents a design of FCS for eBus that integrates MEG with hybrid energy storage with the energy management system. To reduce the dependency on the main utility grid, a hybrid micro energy grid based on a renewable source (i.e., PV) have been included. In addition, hybrid energy storage of batteries and flywheels has also been developed to mitigate the power demand of the fast-charging station during peak time. Furthermore, a multiple-input DC-DC converter has been developed for managing the DC power transfer between the common DC bus and the multiple energy sources. Finally, an energy management system and the controller has been designed to achieve an extensive performance from the fast charging station. MATLAB Simulink has been used for the simulation work of the overall design. Different test case scenarios are tested for evaluating the performance parameters of the proposed FCS and also for evaluating its performance.

The present review paper aims to shed lights on the concept of fully green energy system which includes both the source of energy and the storage system. The objective is to propose an energy label “Green to Green” (G2G) that identifies systems involving simultaneously green source and green storage, as an efficient solution to achieve a significant reduction in the dangerous level of pollution that most countries have reached today. Green sources include mainly renewable energy systems such as solar, wind, geothermal and wave energy systems. In its turns green storage includes pumped hydroelectric, flywheel, hydrogen and compressed air. Moreover, and as a case investigation on G2G concept, the paper reviews the main solar-hydrogen coupling systems, that are categorized within four categories parabolic trough-hydrogen, solar tower-hydrogen, photovoltaic-hydrogen and solar chimney-hydrogen.

Hill, MW, Roberts, M, Price, MJ, and Kay, AD. Effects of flywheel training with eccentric overload on standing balance, mobility, physical function, muscle thickness, and muscle quality in older adults. J Strength Cond Res 36(11): 3190-3199, 2022-This study investigated the effects of a 6-week eccentric overload flywheel training program on vastus lateralis (VL) and gastrocnemius medialis (GM) muscle thickness and muscle quality (echo intensity), mobility (Timed Up and Go [TUG]), physical function (sit-to-stand), and balance (postural sway) performance. Nineteen subjects were assigned to either a flywheel training group ( n = 11, age = 66.4 ± 5.2 years) or a control group ( n = 8, age = 65.9 ± 3.8 years). The flywheel group underwent twice weekly squat and calf raise exercises for 6 weeks with outcome measures assessed before and after training or a time-matched control period. Throughout the training, subjects were instructed to contract as fast as possible with maximal effort during the concentric phase and to maximally resist the pull during the eccentric phase. The alpha value was a priori set at p0.05. Statistically significant ( p0.05) mean ( SD ) increases in right and left VL (7.6-9.6 ± 7.7-9.8%) and GM (8.6-8.7 ± 6.4-11.5%) muscle thickness and a reduction in VL (10.2-11.3 ± 5.9-7.9%) and GM (11.7-11.9 ± 5.6-9.6%) echo intensity were accompanied by faster TUG time (13.7 ± 7.0%) improved sit-to-stand performance (17.8-23.5 ± 7.6 - 13.4%) and reduced postural sway (29.7-42.3 ± 13.2-24.2%) after 6 weeks of flywheel training. There were no differences in any outcome measures between the treatment and control group at baseline ( p0.05). Overall, we observed substantial gains in muscle thickness and muscle quality, in addition to enhanced physical function, balance, and mobility performance among older adults after flywheel training, which may have important implications for preserving the functional capacity of older adults.

Due to the low radial restoring force stiffness of the radial high-Tc superconducting maglev bearing (SMB) in high-Tc superconducting flywheel energy storage system (SFESS), it is difficult to provide enough radial constraint when the rotation speed is high. The dynamic simulation analysis of the SFESS rotor was carried out based on the testing and analysis of the static force results of the SMB. On the one hand, according to the results of dynamic analysis, the flywheel rotor would be eccentric when it is subjected to an unbalanced force. On the other hand, because of the special operation mechanism of the SFESS, the flywheel rotor would be prone to be eccentric before rotation. These two types of eccentricity will affect the operating performance of SFESS. Therefore, the research on the working condition of SFESS under eccentric state not only can predict the operating performance of SFESS in extreme cases in advance but also judge whether the SFESS has eccentric operation by comparing the real-time speed value with the preset value, which is of great significance to the further research of the SFESS.

In order to assess the electrical energy storage technologies, the thermo-economy for both capacity-type and power-type energy storage are comprehensively investigated with consideration of political, environmental and social influence. And for the first time, the Exergy Economy Benefit Ratio (EEBR) is proposed with thermo-economic model and applied to three different storage systems in various scenarios, including pumped storage, compressed air energy storage and flywheel energy storage. The impact of the total system efficiency, annual utilization hour, life time, and other key factors are also analyzed. The results show that the EEBRs of pumped storage and compressed air energy storage under peak load shaving condition and flywheel energy storage under frequency modulation service condition are all larger than zero, which means they are all thermo-economically feasible. With extra consideration of political, environmental and social impact, the exergy cost could reduce by about 25% and the EEBR doubles. The sensitivity analysis indicates the similarity and diversity of influence to EEBR between capacity-type and power-type energy storage systems. The former is that energy efficiency is the dominated factor for all three storage systems. The latter is that the difference of exergy benefit mode causes variety in other major factors. For energy-type storage system, like pumped storage and compressed air storage, the peak-to-valley price ratio is very sensitive in energy arbitrage. For power-type storage system, like flywheel storage, the mileage ratio is in leading position in auxiliary service benefit by mileage. In the three cases studied, the pumped storage has the best thermo-economy; the compressed air energy storage is the second, and the flywheel energy storage is the third. The main reason is that the pumped storage has the least non-exergy cost, and flywheel has the most.

In this paper, the purpose of improving the power quality of the standalone wind conversion system (WECS) is to utilize a quasi-impedance (qZ) static compensator (STATCOM) integrated solar photovoltaic (SPV) source network. The standalone WECS has utilized the flywheel energy storage system (FESS) and the self-excited induction generator (SEIG). The SPV power generation network integrates with the STATCOM DC-Link to compensate for the voltage and frequency fluctuations over a longer time. The SEIG terminal voltage and STATCOM DC-link voltage are regulated using an enhanced second-order generalized integrator (ESOGI) with a fuzzy logic controller (FLC). The coordination logic is proposed in order to handle the various scenarios and make the device energy efficient. The unit is built for optimal usage of the electrical energy generated from renewable sources by utilizing physical energy storage systems such as flywheel and battery. In both batteries and flywheels, excess power from the SPV and wind turbines is collected. To verify the performance of the SPV supported STATCOM, the simulation and experimental studies are performed under specific load conditions. This paper describes an optimal way to produce and utilize green power with better energy efficiency. With various current conditions, the typical level of harmonic distortion of the source current is about 1.4% lower than that specified by IEEE Std. 519–2014 for the tolerable 5% level.

A rig for calibrating a continuous-wave coherent Doppler wind lidar has been constructed. The rig consists of a rotating flywheel on a frame together with an adjustable lidar telescope. The laser beam points toward the rim of the wheel in a plane perpendicular to the wheel's rotation axis, and it can be tilted up and down along the wheel's periphery and thereby measure different projections of the tangential speed. The angular speed of the wheel is measured using a high-precision measuring ring fitted to the periphery of the wheel and synchronously logged together with the lidar speed. A simple geometrical model shows that there is a linear relationship between the measured line-of-sight speed and the beam tilt angle, and this is utilised to extrapolate to the tangential speed as measured by the lidar. An analysis of the uncertainties based on the model shows that a standard uncertainty on the measurement of about 0.1 % can be achieved, but also that the main source of uncertainty is the width of the laser beam and its associated uncertainty. Measurements performed with different beam widths confirm this. Other measurements with a minimised beam radius show that the method in this case performs about equally well for all the tested reference speeds ranging from about 3 to 18 m s−1.

In aerospace industry, saving mass on spacecrafts always remain in large demand to save launch costs or increase the available payload mass. A case study is carried out designing a first concept of an additive manufactured flywheel of a reaction wheel, as it is one of the heaviest parts of wheel systems. As an objective the mass is minimized, while obtaining an angular momentum suitable according to mission requirements and maintaining recent performances. As references the SeaSAT mission and a commercial reaction wheel are used. The work includes a preliminary dimension of the flywheels design space by MATLAB calculations, where in total 15 shapes are analyzed and compared. The most promising design space is afterwards analyzed via the finite-element tool ANSYS and is defined as the reference flywheel. The reference flywheel is used for topology optimizations (ANSYS Topology Optimization), where different boundary conditions are considered. The final designed flywheel obtains 16% higher energy density than the reference flywheel and withstands the mission loads. It can be concluded that it was possible to design a flywheel obtaining less mass while keeping the expected performance.

A comparative analysis of the dynamic properties clusters of flywheels and gyrodines for a space robot attitude control when it is addition launching into geostationary orbit and approaches a geostationary satellite for its maintenance is carried out. The results of the analysis for typical turning maneuvers of the robot are presented and the conditions under which the advantages of the gyrodine cluster are highlighted.

Vernier-gimballing magnetically suspended flywheel is often used for attitude control and interference suppression of spacecrafts. Due to the special structure of the conical magnetic bearing, the radial component generated by the axial magnetic force and the change of the magnetic air gap will cause the nonlinearity of stiffness and disturbance. That will lead to not only poor stability of the suspension control system but also unsatisfactory tracking accuracy of the rotor position. To solve the nonlinear problem of the system, this article proposes a proportional–integral–derivative neural network control scheme. First, the rotor model considering the nonlinear variation of disturbance and stiffness parameters is established. Then, the weight of neural network is adjusted by the gradient descent method online to ensure the accurate output of magnetic force. Finally, the convergence analysis is carried out based on the Lyapunov stability theory. Compared with the general proportional–integral–derivative control and the radial basis function neural network control, the simulation results demonstrate that the proposed method has the highest tracking accuracy and excellent performance in improving stability. The experimental results prove the correctness of the theoretical analysis and the validity of the proposed method.

The present study investigated the post-activation performance enhancement (PAPE) of isokinetic quadriceps and hamstrings torque after flywheel (FW)-squat vs. FW-deadlift in comparison to a control condition. Fifteen male athletes were enrolled in this randomised, crossover study. Each protocol consisted of 3 sets of 6 repetitions, with an inertial load of 0.029 kg.m2. Isokinetic quadriceps (knee extension) and hamstrings (knee flexion) concentric peak torque (60o/s) and hamstring eccentric peak torque (-60o/s) were measured 5 min after experimental or control conditions. A significant condition (PAPE) effect was reported (f = 4.067, p = 0.008) for isokinetic hamstrings eccentric peak torque following FW-squat and FW-deadlift, but no significant differences were found for quadriceps and hamstrings concentric peak torques. The significant difference averaged 14 Nm between FW-squat vs. control (95% CI: 2, 28; d = 0.75, moderate; p = 0.033), and 13 Nm between FW-deadlift vs. control (95% CI: 1, 25; d = 0.68, moderate; p = 0.038). This study reported that both FW-squat and FW-deadlift exercises are equivalently capable of generating PAPE of isokinetic hamstrings eccentric torque. Practitioners may use these findings to inform strength and power development during complex training sessions consisting of flywheel-based exercises prior to a sport-specific task.

Salter’s Duck can convert wave energy to mechanical energy with high efficiency up to 90%. The limitations and challenges in the usage of Salter’s Duck for energy production include preventing hydraulic system from the risk of leaking hydraulic oil and removing complex huge fixed bracket. This paper presents the conceptual design and an experimental investigation of a mechanical power-take-off (PTO) system for the floating Salter’s Duck. The PTO system is fully installed inside of the Salter’s Duck. It consists of double counter-rotating flywheels converting the bi-directional rotation of the wave energy converter into a stable unidirectional rotation that drives a rotary generator to produce electricity. The bi-to-unidirectional function is achieved through inertial wheels, thus the novel PTO system is free of large supporting structures and hydraulic cylinders. In this paper, a detailed conceptual PTO design is proposed firstly. Further, the influence of the swing amplitude and rotation period of the wave energy converter on the power extraction efficiency is investigated. Then, the influence of the electrical load on the power-extraction efficiency is researched. In the end, the effect of the speed increasing ratio on the mechanical efficiency is examined. The experimental results show that the new type of generator mechanism can produce electricity stably.

This paper presents a novel fault diagnosis method based on data fusion for a reaction flywheel of the satellite attitude system. Different from most traditional fault diagnosis techniques, the proposed solution simultaneously accomplishes fault detection and identification within parallel fusion blocks. The core of this method is independent fusion block, which uses a generalized ordered weighted average (GOWA) operator to complement the characteristics of output data from long short-term memory (LSTM) neural network and discrete wavelet transform (DWT) so as to enhance the reliability and rapidity of decision-making. Moreover, minibatch normalization is selected to address the problem of covariate shift, realize the adaptive processing of the dynamic information in the original data, and improve the convergence speed of the network. With the high-fidelity model of the reaction flywheel, three common faults are, respectively, injected to collect experimental data. Extensive experiment results show the efficacy of the proposed method and the excellent performance achieved by LSTM and DWT.

Due to the intermittent nature of power generation within a wind farm, power generation often either exceeds or does not meet the export limits of the site. Excess power generated above the export limit is considered as a breach and can cause fines from the local grid operator. The excess energy above the export limit can be exploited to supplement periods of low generation, smoothing the output of the wind farm and providing a larger total output of the site. Due to their resilience to high cycle rates, flywheels are ideally suited to act as an energy store in this scenario. This paper utilises real world data to simulate a wind farm operating in tandem with a Flywheel Energy Storage System (FESS) and assesses the effectiveness of different storage capacities.

Aimed at solving the microvibration issue of spacecraft, this paper adopts two orthogonal Vernier-gimballing magnetically suspended flywheels (VGMSFs) as vibration suppression actuator. The vibration decoupling control law and Vernier-gimballing steering law of the VGMSFs is designed to output the translational and rotational reference displacements of the VGMSFs. By extending the traditional modal decoupling of the magnetically suspended rotor, the on-orbit nonlinear VGMSF system coupled with satellite realizes the precise modal separation and rotation mode decoupling. This method not only realizes complete compensation for the disturbance torque from spacecraft to VGMSFs, but also improves the decoupling precision of Vernier-gimballing moment of VGMSFs. Most importantly, through independent control of translation and rotational modes of on-orbit VGMSFs, the parameter regulation range of spacecraft vibration decoupling controller is greatly enlarged, effectively improving the microvibration suppression effect of spacecraft. The semiphysical simulation results testify the effectiveness and superiority of this method.

This paper investigates the use of fractional order Proportional, Integral and Derivative (FOPID) controllers for the frequency and power regulation in a microgrid power system. The proposed microgrid system composes of renewable energy resources such as solar and wind generators, diesel engine generators as a secondary source to support the principle generators, and along with different energy storage devices like fuel cell, battery and flywheel. Due to the intermittent nature of integrated renewable energy like wind turbine and photovoltaic generators, which depend on the weather conditions and climate change this affects the microgrid stability by considered fluctuation in frequency and power deviations which can be improved using the selected controller. The fractional-order controller has five parameters in comparison with the classical PID controller, and that makes it more flexible and robust against the microgrid perturbation. The Fractional Order PID controller parameters are optimized using a new optimization technique called Krill Herd which selected as a suitable optimization method in comparison with other techniques like Particle Swarm Optimization. The results show better performance of this system using the fractional order PID controller-based Krill Herd algorithm by eliminates the fluctuations in frequency and power deviation in comparison with the classical PID controller. The obtained results are compared with the fractional order PID controller optimized using Particle Swarm Optimization. The proposed system is simulated under nominal conditions and using the disconnecting of storage devices like battery and Flywheel system in order to test the robustness of the proposed methods and the obtained results are compared., Анотація. У статті досліджено використання регуляторів пропорційного, інтегрального та похідного дробового порядку (FOPID) для регулювання частоти та потужності в електромережі. Запропонована мікромережева система складається з поновлюваних джерел енергії, таких як сонячні та вітрогенератори, дизельних генераторів як вторинного джерела для підтримки основних генераторів, а також з різних пристроїв для накопичування енергії, таких як паливна батарея, акумулятор і маховик. Через переривчасту природу інтегрованої відновлювальної енергії, наприклад, вітрогенераторів та фотоелектричних генераторів, які залежать від погодних умов та зміни клімату, це впливає на стабільність мікромережі, враховуючи коливання частоти та відхилення потужності, які можна поліпшити за допомогою вибраного контролера. Контролер дробового порядку має п’ять параметрів порівняно з класичним PID-контролером, що робить його більш гнучким та надійним щодо збурень мікромережі. Параметри PID-контролера дробового порядку оптимізовані за допомогою нової методики оптимізації під назвою «зграя криля», яка обрана як підходящий метод оптимізації порівняно з іншими методами, такими як оптимізація методом рою частинок. Результати показують кращі показники роботи цієї системи за допомогою алгоритму «зграя криля», заснованого на PID-контролері дробового порядку, виключаючи коливання частоти та відхилення потужності порівняно з класичним PID-контролером. Отримані результати порівнюються з PID-контролером дробового порядку, оптимізованим за допомогою оптимізації методом рою частинок. Запропонована система моделюється в номінальному режимі роботи та використовує відключення накопичувальних пристроїв, таких як акумулятор та маховик, щоб перевірити надійність запропонованих методів та порівняти отримані результати.

The Spectrum–Rontgen–Gamma (SRG) space observatory was launched from Baikonur on July 13, 2019, and is currently on a flight trajectory in the vicinity of the collinear Sun–Earth libration point L2. The planned service life of the observatory is 7 years and includes an all-sky survey and in-depth studies of individual objects in the X-ray range 0.3–15 keV. We consider the technical limitations of the mission pertaining to the launch scenario, the spacecraft design and system characteristics, including the data and command transmission, orbital motion and attitude control systems, and the peculiarities of the ground segment used to accomplish these tasks. The flywheel offloading strategy for the attitude control system is analyzed within the mentioned limitations. The goal of this analysis is to determine an optimal balance between the flywheel offloading operations while controlling the attitude of the observatory, the orbital maneuvers to keep it on a given trajectory, propellant consumption, and the requirements from the scientific measurements. The proposed method allows the total propellant consumption to be minimized by coordinated control of the operation of the system of attitude control rocket engines while simultaneously using them to maintain the specified orbital parameters.

Developing a microcontroller-based system for controlling the flywheel motor of high-dynamics spacecraft using Russian-made parts and components made it possible to make statement of the problem of searching control function for a preset rotation rate of the flywheel rotor. This paper discusses one of the possible options for mathematical study of the stated problem, namely, application of structural analysis based on graph theory. Within the framework of the stated problem a graph was constructed for generating the new required rate, while in order to consider the stochastic case option the incidence and adjacency matrices were constructed. The stated problem was solved using a power matrix which transforms a set of contiguous matrices of the graph of admissible solution edge sequences, the real-time control function was found. Based on the results of this work, operational trials were run for the developed control function of the flywheel motor rotor rotation rate, a math model was constructed for the real-time control function, and conclusions were drawn about the feasibility of implementing the results of this study. Key words: Control function, graph, incidence matrix, adjacency matrix, power matrix, microcontroller control of the flywheel motor, highly dynamic spacecraft.

In this paper, the complementary characteristic of battery and flywheel in a PV/battery/flywheel hybrid energy storage system is explored for a solar PV-powered application. The impact of hybridisi...

It is known that the synthesis of the relevant control law is performed and appropriate control devices are selected for specific tasks of controlling relative spacecraft motion. Flywheels, control moment gyroscopes, electromagnetic devices with permanent magnets and micro-jet engines are used as actuators in controlling the orientation and stabilizing the spacecraft. For example, flywheel motors together with electromagnets are most often used to ensure precise spacecraft stabilization in remote Earth monitoring (REM) problems. At the same time, there is a series of problems pertaining to the control over the relative motion of spacecraft where there is no need for precise spacecraft stabilization and ensuring minimal errors in orientation. These problems may include spacecraft orientation for charging solar batteries or orientation control for research and meteorological spacecraft. The study's purpose is to synthesize a law for spacecraft orientation control algorithm when using executive devices with permanent magnets (EDPM). EDPMs are the devices controlling spacecraft orientation. They consist of rotary permanent magnets, stepper motors, and capsule-screens with shutter flaps. Opening and closure of the capsule-screen flaps and rotation of permanent magnets in a certain way ensure the generation of a discrete control magnetic moment. It should be noted that EDPMs do not provide accurate spacecraft stabilization and hence they are not suitable for the REM purpose. However, EDPMs consume less on-board energy than other spacecraft orientation control systems and are useful in problems requiring less accurate stabilization. A control law was synthesized for controlling spacecraft equipped with EDPM using a nonlinear controller and a pulse-width modulator. Areas of effective EDPM application for various space-related problems including orientation and stabilization of aerodynamic elements perpendicular to the dynamic flow of the incoming atmosphere were determined. Advantages of using EDPMs in comparison with electromagnetic executive devices in the problems pertaining aerodynamic element stabilization in aerodynamic systems of deorbiting worked-out spacecraft from low Earth orbits were shown

Introduction: there is much concern about power supply to small and remote villages and industrial facilities, such as crude oil and gas fields, in the present-day power industry. Systems using renewable energy sources are the most innovative solutions to this problem. The need for electric energy storage units complicates the use of renewable energy sources. Versatile types of storage units, working on different principles, are in use now. Flywheels, working on the principle of mechanical accumulation of energy, are of particular interest.Methods: both traditional and advanced designs of electric energy accumulation systems are analyzed in the article. Recent advancements in machine building, power engineering and structural materials are contributed into structural elements of an electric energy accumulation system.Results and discussion: basic strengths and weaknesses of electric energy storage units were identified in the course of the analysis. The author substantiated the need for new effective electric energy storage units working on the principle of mechanical accumulation of potential and kinetic energy. The conclusion is that advanced engineering solutions, such as flywheels and energy efficient reversible electric machines, can boost the efficiency of electric power storage systems. The solution underlying the design of an energy efficient storage unit is offered to electric power industry players.Conclusion: the storage unit under development has flywheels and energy efficient reversible electric machines. It improves the energy efficiency of both classical power generation systems and those using renewable energy sources.

The modern world is continuously focusing on a carbon-free atmosphere to improve environmental sustainability. In the last two decades, Human Powered Flywheel Motor has been applied to design numerous rural-based applications. The functional feasibility and economic viability of Pedal-powered process machines of 3 to 5 Horse Power capacity over motorized machines have increased the utility for rural-based applications. The present work deals with the review of various research investigations done on the Human Powered Flywheel Motor system. Further, the conversion of the Human Powered Flywheel Motor into the electromechanical analog circuit and the generation of design data for Human Powered Flywheel Motor through the establishment of generalized experimental data-based models have also been discussed. It is concluded that the Human Powered Flywheel Motor can generate a maximum of 3 to 5 Horse Power, which can be utilized against the various motorized machines in rural applications where intermittent power supply does not affect the end quality of the product.

Variable valve timing (VVT) enables the valve events to vary with RPM for optimum engine performance. It alters the timing on the camshaft using pneumatic, hydraulic or electromechanical means. The Cameless Stepping Valve system uses software controlled valve events. Here, VVT is achieved by advancing/retarding valve events using only the direction of the piston and interpolated virtual angles on the flywheel. The engine model used has an optimum RPM of 24000, which translates to a period of 2.5mS. A 10 angle increment on the flywheel corresponds to 6.9µS. As a result, a retardation/advance of 10 would mean that the valve will open/close 6.9µS after the current/previous TDC. A 9bit real-time digital counter was triggered to count the calculated angles at every Otto Cycle so that advance/retard is updated at every RPM. In this project, it was demonstrated that valve event control is possible using interpolation of virtual angles on the flywheel, replacing a multi-tooth timing wheel. The proposed technique is more accurate and robust.

In this work, a 370-W small wind turbine was developed which is equipped to a controllable nuzzle-diffuser duct. The developed duct is consisting of a fixed ring and a two-piece diffuser which can rotate on each other and so the diffuser wall opening will have altered from 0 to 180°. This mechanism is developed to control speed-up ratio and drag forces acting on the turbine structure in high ranges of wind speeds. The rotor is designed using BEM algorithm and the duct geometry is reached by CFD works considering the atheistic aspect of view. As the turbine is designed for a comprehensive research project, so it contains several a subsystems like an electromagnetic brake, external electric starter motor, electromagnetic flywheel, variable nacelle, etc. The designed mechanism fabricated using several machining processes as turning, milling, boring, drilling, welding and rolling works. The turbine performance implemented in a low-speed wind tunnel. Experimental results show a comprehensive raise in power generation and rotor speed by shrouded wind turbines. In the 180-degree diffuser wall opening, the augmentation ratio in average is 39.75% while the ratio is 28.5% for a complete diffuser augmented wind turbine. The rotor speed-up ratio for them is 53 and 74% respectively.

The research and development of electrical energy storage technologies for stationary applications in China is reviewed. Particular attention is paid to pumped hydroelectric storage, compressed air, flywheel, lead–acid battery, sodium–sulfur battery, lithium-ion battery, and flow battery energy storage. Research and development into electrical energy storage has experienced fast and fruitful development over the past (10–15) years in China, and by all accounts electrical energy storage has a bright future in China.

Remote farms in Africa are cultivated lands planned for 100% sustainable energy and organic agriculture in the future. This paper presents the load frequency control of a two-area power system feeding those farms. The power system is supplied by renewable technologies and storage facilities only which are photovoltaics, biogas, biodiesel, solar thermal, battery storage and flywheel storage systems. Each of those facilities has 150-kW capacity. This paper presents a model for each renewable energy technology and energy storage facility. The frequency is controlled by using a novel non-linear fractional order proportional integral derivative control scheme (NFOPID). The novel scheme is compared to a non-linear PID controller (NPID), fractional order PID controller (FOPID), and conventional PID. The effect of the different degradation factors related to the communication infrastructure, such as the time delay and packet loss, are modeled and simulated to assess the controlled system performance. A new cost function is presented in this research. The four controllers are tuned by novel poor and rich optimization (PRO) algorithm at different operating conditions. PRO controller design is compared to other state of the art techniques in this paper. The results show that the PRO design for a novel NFOPID controller has a promising future in load frequency control considering communication delays and packet loss. The simulation and optimization are applied on MATLAB/SIMULINK 2017a environment.

This paper presents a sensitivity analysis on the power to energy ratio for Energy Storage Systems (ESS) providing frequency response services on the Great Britain electricity network. Two services are considered; dynamic frequency response and dynamic containment, with the latter being a new service introduced in Oct 2020 by the Electricity System Operator. Each service proportionally responds in power to changes in grid frequency with each service differing in the response envelope. Whilst these services are based on power, for energy-limited assets such as ESS, the ratio of power to energy has an effect on its ability to deliver the service 100% of the time. In this paper, the availability, compliance against service terms and conditions, and equivalent cycles are considered showing that there is a significant difference between the two services. Currently, these services are delivered by battery ESS, however, it is demonstrated that the newer dynamic containment service can be effectively delivered by a higher power to energy ratio ESS and therefore offers opportunities for other technologies such as supercapacitors and flywheels.

The development of wearable devices and remote sensor networks progressively relies on their increased power autonomy, which can be further expanded by replacing conventional power sources, characterized by limited lifetimes, with energy harvesting systems. Due to its pervasiveness, kinetic energy is considered as one of the most promising energy forms, especially when combined with the simple and scalable piezoelectric approach. The integration of piezoelectric energy harvesters, generally in the form of bimorph cantilevers, with wearable and remote sensors, highlighted a drawback of such a configuration, i.e., their narrow operating bandwidth. In order to overcome this disadvantage while maximizing power outputs, optimized cantilever geometries, developed using the design of experiments approach, are analysed and combined in this work with frequency up-conversion excitation that allows converting random kinetic ambient motion into a periodical excitation of the harvester. The developed optimised designs, all with the same harvesters’ footprint area of 23 × 15 mm, are thoroughly analysed via coupled harmonic and transient numerical analyses, along with the mostly neglected strength analyses. The models are validated experimentally via innovative experimental setups. The thus-proposed ϕ = 50 mm watch-like prototype allows, by using a rotating flywheel, the collection of low-frequency (ca. 1 to 3 Hz) human kinetic energy, and the periodic excitation of the optimized harvesters that, oscillating at their eigenfrequencies (~325 to ~930 Hz), display specific power outputs improved by up to 5.5 times, when compared to a conventional rectangular form, with maximal power outputs of up to &gt, 130 mW and average power outputs of up to &gt, 3 mW. These power levels should amply satisfy the requirements of factual wearable medical systems, while providing also an adaptability to accommodate several diverse sensors. All of this creates the preconditions for the development of novel autonomous wearable devices aimed not only at sensor networks for remote patient monitoring and telemedicine, but, potentially, also for IoT and structural health monitoring.

Wind, solar, fuel cell, small hydro, etc., are emerging technologies for renewable energy and can be built in the future as feasible electricity generation options. This paper introduces the load frequency control (LFC) in the presence of renewable energy resources. The study considers Wind turbine generator (WTG), Solar thermal power system (STPS), Photovoltaic (PV), Diesel source (DEPS), Fuel cell (FC), Battery storage system (BESS), Flywheel (FWES), Ultra capacitor (UC) and Aqua electrolyzer (AE), for sudden load/generation shifts, or both, the power system frequency deviates. The addition of a renewable system also results in a difficult task for an efficient controller design to be realized. With random load variance, the complexity to design an efficient and optimal control scheme is further enhanced. In this study, as an LFC control scheme, a PID controller is used. Two evolutionary approaches named as Big Bang Big Crunch (BBBC) and Harmony Search (HS) have been used to obtain optimal parameters. The performance of the control scheme has been checked two area and three area thermal-hydro system in the presence of other generation and energy storage sources. A comparative assessment of various quantities has been carried out on the basis of different time-domain parameters.

Energy is ultimate need for mankind activity and for fruitful and social invention but due to rise in population linked with global warming and faster observance of fossil fuel resources, human being is in desirous need of alternative technologies based on Renewable Energy Sources(RES). The grid integration of RES is most promising technology nowadays. It will reduce the load on the grid. On the contorory, this integration introduces issues in the grid system. The integration of RES has an impact on Power Quality, Stability, Voltage Ride Through(VRT), Active and Reactive Power Control of Grid. This paper analyse the impact on power quality of grid when integrated with RES. This paper discusses the challenges of grid integration of large scale RES. Moreover, it reviews the various mitigation techniques of power quality issues. The Energy Storage System(ESS) is one method to damps out power quality issues. The ESS consists various type of Batteries, Supercapacitor, Superconducting Magnetic Energy System(SMES), Flywheel, etc. Hybrid Energy Storage System(HESS) is noval concept which is reviewd in this paper.

This paper introduces the modeling and control of split-shaft drivetrains where the system’s inertia is adjusted to store the energy. Accordingly, a flywheel is mechanically coupled with the rotor of a doubly fed induction generator. The generator is driven by a split-shaft drivetrain that decouples the turbine’s shaft from the shaft of the generator to provide independent control of their angular velocities. Hence, the turbine controller can track the point of maximum power while the generator controller can adjust the generator speed. Accordingly, the flywheel, which is directly connected to the shaft of the generator, is charged and discharged by controlling the generator speed. In this process, the flywheel can modify the electric power generation of the generator on-demand. Since the drivetrain is a split-shaft, the turbine speed is not affected by this energy storing process. This improves the quality of injected power to the grid. The structure of the flywheel energy storage can be simplified by removing its dedicated motor/generator and the power electronics driver. This significant modification can only occur in the split-shaft drivetrain. Two separate supervisory controllers are developed in the form of fuzzy logic regulators to generate a real-time output power reference. Furthermore, small-signal models are developed to analyze and improve the maximum power point tracking controller. Extensive simulation results demonstrate the feasibility of such a system and its improved quality of power generation.

Vertical rotors are often used as components of energy machines or flywheels for energy storage. Application of the contactless bearings makes it possible to minimize resistance against their rotation, wear, and energy losses. The advanced technological solution consists in utilization of permanent magnetic bearings or magnetic rings lifting the vertical rotors mounted in rolling element bearings to reduces their axial loading. The carried out research was focused on investigation of a rigid rotor supported at its upper end by a rolling element bearing inserted in a squeeze film damper and coupled with the stationary part by a shear magnetic bearing at its lower end. The bearaing is composed of two permanent magnets, one is attached to the stationary part and one to the rotor. The magnets are mutually attracted, which returns the rotor always to the equilibrium position during its vibration. In the developed computational procedure the rotor is represented by an absolutely rigid body and the permanent magnets by electric coils powered by equivalent current. The frequency response shows that application of the proposed magnetic bearing reduces amplitude of the rotor vibration in the range of lower velocities.

In order to improve the frequency stability of power grid under high penetration of renewable energy resources, an automation generation control (AGC) strategy with the participation of hybrid energy storage resources composed of power-type flywheel energy storage system (ESS) and energy-type electrochemical ESS is proposed. Based on the modeling of grid AGC, first, considering the historical data of frequency regulation (FR) demand, the Discrete Fourier Transform (DFT) is used to analyse features of area control error (ACE) in frequency domain. The filter frequency is determined reasonably by frequency trial method. Then, the high-frequency component in ACE is allocated to flywheel ESS, while electrochemical ESS and traditional FR units are responsible for the low frequency component. Further, considering that over-charge or discharge would affect the life of electrochemical ESS, the real-time state of charge (SOC) is used to correct the maximum power output of electrochemical ESS. Finally, a simulation example is given to verify the effectiveness of the proposed strategy.

The purpose of the present meta-analysis was to examine the effect of flywheel resistance training (FRT) on main sport action (i.e., jumping performance, sprinting time and change of direction performance) improvements in athletes and healthy active people. A Boolean search strategy adapted for each of the databases employed was conducted to identify all studies measuring change in sport actions performance after FRT interventions up to July 2019. Outcomes were analysed using an average effect size (D+) and a 95% confidence interval (CI), which was calculated assuming a random-effects model. A total of 9 studies with 283 participants met the inclusion criteria and were selected for the analysis. The mean quality score (PEDro scale) of the articles included in the meta-analysis was 5.67. The meta-analysis showed significant positive effects on jumping performance (SMC 0.65; 95% CI, 0.11-1.19; p = 0.02), sprinting time (SMC 1.33; 95% CI, 0.39-2.28; p < 0.01) and change of direction performance (SMC 1.36; 95% CI, 0.58-2.14; p < 0.01) after FRT interventions compared to control/traditional resistance training groups. The results of the present meta-analysis provide evidence of the usefulness of FRT to improve variables related to sport performance in both athletes and healthy population.

A method for ensuring the survivability of a spacecraft attitude control system with minimally redundant cluster of the flywheels and magnetic actuator at the faults of any flywheels are presented. The results of computer simulation were obtained and it was found if any two of the four flywheels according to the General Electric scheme fail, digital control of the flywheel cluster and magnetic drive allows the Earth-observing satellite to maintain observation of given terrestrial targets.

Frequency response services are an increasingly essential service to the stability of the UK electrical distribution system. Due to this, it is a prime target for deployment of energy storage systems. This market is currently dominated by conventional Battery Energy Storage Systems (BESSs) due to their maturity as a technology and favorable technical characteristics. Flywheel Energy Storage Systems (FESSs) are not commonly deployed for this service due to their generally high power/energy ratio and traditionally high manufacturing costs, however, the ongoing development of new FESSs with a wide range of technical characteristics and reduced costs presents an opportunity for re-evaluation. Here we show the results of a techno-economic study that identifies an appropriate target power/energy ratio range and necessary target cost (£/kW) for a FESS to be a viable option for providing frequency response services. The study subsequently discusses the techno-economic effects of hybridization of the system with BESS technology providing the framework for further analysis. The results of this study provide potential flywheel manufacturers with the information necessary to develop commercial systems for this application.

The present study examined whether differences in the heart rate recovery following flywheel exercise cessation were associated with differences in maximal oxygen uptake ($${\dot{\text{V}}}$$ V ˙ O2 max.), age and sex in trained adults. Eleven men (age range 22–49 years, $${\dot{\text{V}}}$$ V ˙ O2 max. = 43.6 ± 7.6 mL kg min−1) and ten women (age range 20—53 years, $${\dot{\text{V}}}$$ V ˙ O2 max. = 38.0 ± 5.7 mL kg min−1) were randomly assigned to complete a squat-exercise on the flywheel ergometer set at three different moments of inertia, while their cardiovascular responses were continuously monitored. During the flywheel exercise the mean arterial pressure rose by ~ 35 to 40% (p = .001), and the increment was more robust in men than women. The cardiac index was two-fold greater across both sexes compared to the baseline (p = .001), while the rise in heart rate (~ 144 bpm) was more pronounced in women to compensate for their load-dependent stroke index decline (p = .001). The load-independent time-course changes in heart rate recovery markers were comparable between the sexes. When these indicators were pooled, a stepwise regression revealed age as the only relevant predictor of both fast and slow components of the heart rate recovery (~ 30% of the shared variance explained, p = .014). The present data suggest that the heart rate recovery declines with age, irrespective of sex, or well-preserved cardiorespiratory fitness in moderately-trained adults.

This paper investigates optimal PID controller tuning using particle swarm optimization for frequency control in the microgrid system. The proposed microgrid composed of renewable sources such as wind turbine generation and solar system with diesel engine generator and storage systems such as the battery, flywheel, aqua electrolyze, and fuel cell. The microgrid based on renewable energy sources faces different challenges in operation and stability due to the stochastic nature of solar radiation and wind speed that depend upon the weather conditions. Among these challenges, the frequency and power deviations are affected by the sudden unbalance between generation and load which require a suitable and adequate regulation. The principal objective of this study is to reduce the frequency and power deviation by the use of the PID controller optimized based particle swarm optimization due to its simplicity and flexibility to overcome this kind of issues. The simulation results show the better performances and robustness of the proposed controller against the disturbances in load and generations in comparison to using a genetic algorithm.

The optimal parameters of a compact kinetic energy storage device are considered, which allow to cover the widest range of consumers of autonomous solar power plants. Estimated consumer market volumes. A comparative characteristic of various types of electrical energy storage devices is carried out. The advantages and disadvantages of each of the existing types of drives are indicated. The cost characteristic of one charge-discharge cycle of electrochemical storage devices is given. The combined use of kinetic and electric energy storage devices in the structure of a hybrid storage device is shown with the aim of optimizing the cost of generating electric energy from alternative sources of electric energy. In this case, the compensation of high-frequency voltage ripples is carried out due to the energy previously stored in the kinetic storage device. Technical problems arising when using kinetic energy storage devices (flywheels) are considered. These include the presence of a gyroscopic effect that does not allow mobile performance of the drive, as well as special requirements for the material from which the flywheel is made. Possible features of the design of flywheel-based drives are considered. The use of magnetic compensation of the centrifugal forces of the flywheel eliminates the use of high-strength and expensive materials.

In this study, an improved centripetal force type-magnetic bearing (CFT-MB) for a flywheel battery system is proposed, which is easy to process and it has better performance with superior stiffness and anti-interference characteristics than that of the pure spherical CFT-MB. First, the configuration, magnetic circuits, working principle and mathematical model of the improved CFT-MB are analyzed in detail. The electromagnetic characteristics are then analyzed. In comparison with the analysis results of the pure spherical CFT-MB, the improved CFT-MB has less cost, less force–displacement and force–deflection stiffness, and higher force-current stiffness, which verify its preferable design concept. Related comparative experiments based on the prototype are also conducted. The stiffness tests results verify the accuracy of the previously presented electromagnetic characteristic analysis results. Performance tests results show that the proposed improved CFT-MB is superior to that of the original CFT-MB in resisting to the disturbance or the gyroscopic effect, which verifies the accuracy of the theoretical analysis.

Flywheel energy storage system (FESS) is new advanced machinery which is intended for electric power storage and release. A FESS, which is suitable for the small flywheel, was developed with a permanent magnet bearing (PMB) and a single point flexible support, and its friction loss is very low. By means of the Lagrange theory, a dynamic model was established. The Campbell diagram, mode shapes, modal damping ratios and critical speeds were designed after the flywheel data at different operating speeds was obtained by numerical simulation. Based on the excitation test and single freedom vibration theory, the stiffness and damping coefficient of the upper and lower damper was measured. The influences of damper dynamic parameters on modes of flywheel rotor bearing system were discussed in detail. The comparison between the calculated unbalance response and the experimental response indicates that the dynamic model is appropriate. The results showed that the lower damper absorbed vibration energy of the flywheel rotor, which increased vibration of the damping body. And the bigger damping coefficient had better vibration absorption effect. The developed FESS is simple, stable and efficient in structure.

A control moment gyroscope (CMG) is capable of generating strong restoration torque with a relatively small-sized flywheel by changing the direction of flywheel momentum. Because the CMG is energy efficient, it has been used for active balancing of a bicycle that has an unstable equilibrium point in its dynamics. A single CMG generates not only the restoration torque component but also an additional unwanted torque component. In contrast, a scissored-pair CMG cancels out the unwanted torque and doubles the restoration torque. This study deals with active balancing to implement an unmanned bicycle by using a scissored-pair CMG. Based on the inverted pendulum dynamics model of a bicycle, a linear quadratic regulation algorithm is presented for balancing control. In order to investigate active balancing, a miniaturized bicycle system is developed, and its 3D solid model is created to obtain the parameter values of the dynamics model. Two kinds of disturbances exist that can cause the instability of a bicycle with an unstable equilibrium point: impulsive external disturbance and static constant disturbance. Experimental results show the performance of active balancing for a bicycle with a scissored-pair CMG against those disturbances.

This paper investigates the development and application of a nonlinear adaptive intelligent controller with superior disturbance-rejection capability for a doubly-fed-induction-machine driven flywheel energy storage system (FESS), to mitigate the intermittency in wind power injection, as well as enhance the transient stability of the connected multimachine power system thereby isolating the grid power from fluctuations. Intelligent supervisors for the rotor-side-converter of the FESS have been constructed using a fuzzy rule set. The consequent part in every rule includes a wavelet function for function learning. The novel normalized gradient descent algorithm with adaptive learning rate has been used to derive the update laws for unknown controller parameters. The control law has been derived by minimizing the predictive performance index. Convergence of the developed algorithm is guaranteed as proven via the Lyapunov stability method. Realistic wind speed profile has been used to test the efficacy of the developed control scheme. The sizing strategy has been devised for optimal sizing of FESS for its efficient utilization. Modified WSCC nine-bus test system has been used for the nonlinear time-domain simulations and novel indices have been used for evaluation of controller performance against its predecessors. $\boldsymbol{OP}{\text{5600}}$ Real-Time-Digital-Simulator has been used to demonstrate the real-time implementation of the suggested scheme.

In this study, an advanced control strategy is proposed for hybrid energy storage systems (HESS) to smooth wind power generation fluctuations. Compared with the limited performance of solo energy storage system, the HESS, composing of lithium-ion battery (LiB) and a flywheel energy storage system (FESS), can comparatively show improved flexibility and adaptivity. A novel sequence control scheme for the HESS is proposed in this study to improve the overall economic and smoothing performances. Specifically, based on variable-interval reference outputs, the control horizon of the HESS is statistically determined. Afterwards, a sequence control scheme for the HESS is presented to improve the internal collaboration of HESS media. Especially when the LiB and FESS are synchronously charging/discharging to smooth wind power, the charge/discharge power are optimally distributed between the LiB and FESS via an optimiser to minimise the equivalent cost during each control cycle. Case studies are conducted to demonstrate the performance of the proposed method.