Papers by Keyword: Flywheel Energy Storage System

Abstract: 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.

Abstract: This paper presents a finite element investigation into the copper losses and rotor eddy current losses in brushless DC motors used in a flywheel energy storage system. The copper and rotor losses generate heat which needs to be dissipated in order to not exceed a defined temperature level for the magnet or winding insulation to avoid demagnetization or damage, which if it occurs will reduce the motor performance. The principle of operation and losses calculations are presented in the paper. The influences on the copper and eddy current losses are analyzed in detail, including the operation mode, the control strategy and the variation of the speed. Simulation and experimental results are presented and discussed.

Abstract: Flywheel Energy Storage System (FESS) has become an important research field because of the energy problem. To solve the control of Permanent Magnet Synchronous Motor (PMSM) and Bi-directional power converter, both charging and discharging control strategiesthe Compound Control for charging and the Integrated Optimization Flux-Weak Control for discharging are proposed, together with the dual-loop control and simulation results. Based on these analysis and results, a high-power DSP-controlled experiment platform is set up to test the proposed strategies. Simulation and experiment results show that the FESS can run smoothly both under charging and discharging conditions so that both the strategies and the platform are effective.

Abstract: The working principle of Flywheel Energy Storage Systems (FESS) is described. Then the FESS's key technologies are analyzed: FESS is an integrated system which has the feature of multidiscipline intersection. To improve its performance indexes, the rotational drag, electromagnetic coupling and created heating of FESS should be decreased. Therefore, the key technology affecting FESS includes flywheel design, magnetic bearings technology, high-speed rotor dynamics, motor/generator and energy conversion technologies, and long time maintaining vacuum technology. Lastly the FESS's application status is discussed: With the development of key technologies, the application of FESS has extended to the fields of UPS, grid, marine etc.

Abstract: In this paper, a dynamics model of flywheel rotor - support system is build. Obtained the dynamic characteristics of the flywheel rotor by finite element method .The results indicate that the rotor system is stability and security. This provides the basis for the subsequent optimization of flywheel rotor.

Abstract: We have proposed a method to cooperative control both fly wheel energy storage system (FWES) and micro gas turbine (MGT) electrical generation system in micro grid system because the capacity of the electric power storage equipment used for electric power compensation is desirable to have low capacity as much as possible from the viewpoint of cost. The speed information of FWES is necessary in order to perform the cooperative control. When system composition is considered, it is desirable to use a speed observer instead of a rotoring speed sensor from the viewpoint of cost and maintenance side. Therefore, the adaptive rotor flux observer is proposed in of this paper. And the validity of adaptive rotor flux observer is confirmed by the simulation.

Abstract: A prototype of flywheel energy storage system is developed for light rail-trains in cities to store the braking energy. The prototype is designed to have a rotor of 100kg rotating at up to 27000rpm, which can store 1kWh energy and supply 10kW maximum power. Main works and results are described. Difficulties and some key techniques are presented. Test of the system operation is still not finished. Now the system is able to run at 16800rmp. Maximum power output is 3kWh.

Abstract: This study presents a novel bidirectional dc-dc buck-boost converter compatible with the flywheel energy storage system (FESS) and a robust control for bidirectional power flow, according to the single cycle average current control scheme and proportional-integral (PI) control theory. The proposed converter and its control are designed to adjust voltage to achieve current limiting start up and final speed keeping of the motor in charge mode and maintain a constant output voltage in the case that terminal voltage of the motor in the FESS drops continually in discharge mode. Simulation results demonstrate high performance of the converter in both steady-state and dynamic operations.

Abstract: A novel kind of flywheel energy storage system structure for vehicle is put forward and studied. Flywheel rotor dimension optimization is achieved adopting genetic algorithm on MATLAB program, optimized dimension is helpful for the realization of high energy storage efficiency. Based on certain uniform ring simplification of flywheel rotor shape and applying elastic mechanics solution, theoretical calculation of radial displacement and stress is accomplished. Solved radial displacement, radial stress and hoop stress can be applied in practice for further precise design in the view of mechanical strength.

Abstract: The basic working principle of a Flywheel Energy Storage System (FESS) is introduced. From the angle of failure detection means and fault types, the status and deficiency of the research on FESS Fault Diagnosis (FD) and Fault Tolerant Control (FTC) are reviewed. Moreover, the FESS FD and FTC methods are analyzed in detail. Finally, the deficiency, research hotspot and development trends of FESS FD and FTC are discussed.