Papers by Keyword: Energy Storage System (ESS)

Abstract: The energy storage system (ESS) is playing an important role in the hybrid system. Because of the high power density of the supercapacitor (SC) and the high energy density of the battery, the hybrid ESS with the two energy storing devices is widely used in the hybrid vehicles. But the research on the hybrid ESS in hybrid construction machinery is nearly blank. According to the characteristics of the hybrid ESS, the structure applied to the hybrid construction machinery is put forward, and the power converter DC-DC is designed and simulated, too. The simulation results prove that the bidirectional DC-DC can meet the requirement of the hybrid ESS.

Abstract: In this paper, the optimal schedule for power output of a wind farm with storage units and forecasting system has been studied. Optimal schedule for wind power output aims at maximizing expected schedule income and minimizing cost over the required period. We present a practical method to solve the problems based on forward dynamic programming algorithm. It is demonstrated by simulation that the method presented in this paper can ensure one to get a feasible and profitable schedule for wind farm.

Abstract: In order to improve the energy efficiency of electric vehicle (EV) power battery, and increase the start-up power of EV, a kind of maglev flywheel battery storage energy system is designed on EV, it is active suspension controlled at five degrees of freedom. The system suspension control principle is expounded, and the radial single freedom transfer function of the maglev flywheel is established combining with a digital PID control algorithm. The frequency spectrum characteristic of the transfer function and the flywheel rotor trajectory curve are simulated, and the 30000 r/min rotation experiment of the maglev flywheel battery prototype is realized. The experiment result shows that the maglev flywheel rotor may high speed and steadily spin, and has good energy storage ability. The maglev flywheel battery storage energy system can assist the EV power battery work, improves the battery charge and discharge properties and prolongs the service life of the motive power battery.

Abstract: This manuscript introduces and reviews the background, necessity, opportunities, and recent research progresses for investigating and applying the secondary use of plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs) lithium-ion (Li-ion) batteries in stationary applications. And the motivation, objective, and plans of our PHEV/EV lithium-ion battery secondary-use program are also described in detail.

Abstract: Recently, a lot of PV power systems ranging from 1MW to 10MW have been built in China. However, the power grid can’t accept so much PV power because of their oscillated output power. PV systems are affected by the weather condition a lot, such as the sunlight and the temperature. Embedding energy storage system into PV system could improve the grid-access performance of PV systems as well as expand the functions of original PV systems, including regulating power quality of grid. In this paper, PV-storage topology is presented and the flow direction control (FDC) method is described. Based on the operation data of a 100kW PV system in a certain place of China, simulation studies are performed. The result of simulation verifies the possibility and necessity of building the energy storage system in the PV system. With the decline of the cost of energy storage system and PV system, the development of renewable energy in China will be accelerated and supported by the combination of PV system and energy storage system.

Abstract: Based on power system static voltage stability constraints, by theoretical analysis, calculation method of injection power for each node in power system is given. Compared with power flow simulation, results show that this method can be used to obtain nodes with relative large injection power, and calculation accuracy in a certain extent depends on the accuracy of power system Thevenin equivalent impedance. In addition, the application of energy storage systems to improve wind farm power injection is analyzed preliminarily. Simulation results show that locations of energy storage system in power system have impacts on the improvement of wind farm power injection.

Abstract: As part of micro grid, energy storage system provides an essential part in smart grid, it enables renewable, and is ready to be deployed today. This paper introduces the technology readiness levels (TRL), which can divide the investment process of energy storage into several phases, optimize the investment timing, and reduce the technology investment risk. This paper is aiming to give suggestion on the issues of energy storage system’s implementation process, and we analysis the feasibility of the standard in theory and verify it in a case study.

Abstract: The energy storage system can be engaged to smooth the fluctuation output of wind power for better power quality and stability of power grid. The paper proposes a low-pass-filter-based smooth control model of the wind-storage combined system. Then the paper proposes the evaluation indices which depict power fluctuation of the combined system without/with smooth control, on which the installation storage capacity is optimized. All simulation is done on the basis of measured data

Abstract: With people attaching importance to sustainable development and reducing environmental pollution, distributed generation technology is attracting more and more and more attention due to its unique environmental protection and economy. However, distributed generation will change with natural conditions so that it can not output power constantly and steadily, and most DGs are connected to the power system at distribution network side, this will cause system stability problem. In order to fully play the role of distributed power and avoid the adverse effects of its existence, a power conversion sand energy storage system to effectively regulate the system stability of distributed generation connected to the grid is presented. MATLAB/Simulink is used as a simulation and study tool in this paper, a system model of distributed generation connected to the grid is built and combined with actual operation in different environments to conduct real-time simulation analysis, the simulation results show that the power conversion system can enhance system stability of distributed generation connected to the grid.

Abstract: In the early research work,the concept of building energy smart grid based on natural gas based distributed energy system is proposed. For design of energy storage system applied to NDES-SG, basic principles of system design are given which follows energy saving and efficiency increasing in this paper. To interpret integration, energy saving potential and system evaluation method of NDES-SG, Combining with design principles of energy storage system, a simplified typical case system is presented. The influence of energy storage system design on the NDES-SG performance is studied taking ice thermo storage system as an example and system energy saving rate for evaluation criteria. The results show that NDES-SG with a reasonable storage system design can realize energy saving rate approximately 30% compared with NDES-SG without energy storage system. NDES-SG system energy efficiency is further improved.