Papers by Author: Bei Li

Abstract: Vanadium Redox Flow Battery (VRB) holds unique characteristic as the power and capacity of the physical structure of independent design, which determines VRB different from other battery types in operating characteristics by taking unique operation modes under the circumstance of module degradation or failure in some cases. Paper focuses on how to ride through the case of VRB system with partial degradation or failure during the normal operational conditions, launched a comprehensive experimental study and theoretical analysis. The paper analyzes several situations from the point of view of the battery physical components which should lead VRB system partial failed, and simulated the battery partial degradation or failure by experimental means, and carried out two operation modes to respond to different partial failure situations, which including the use of lower rated power and the use of times rated power. Study proved that those two modes operated in the case of VRB partial failure conditions, has no significant effect to VRB Energy Storage System (ESS) efficiency, as well as be helpful to improve a higher reliability of VRB energy storage system. This paper takes the lead in studying the operational characteristics of VRB- ESS from the angle of partial degradation or failure conditions, which has practical engineering significance for developing VRB -ESS demonstration.

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: The output of photovoltaic generation system is influenced by the factors such as solar radiation, temperature and so on. So the change of photovoltaic generation power is a non-stationary random process that will impact on the grid. In order to promote large-scale photovoltaic generation connected to the grid, we need to configure energy storage devices for photovoltaic power station and in order to coordinate the allocation of photovoltaic system with energy storage system, we requires a thorough understanding of output characteristics of the photovoltaic system. This paper firstly analyzes the influence brought by the large-scale photovoltaic generation system connected to the grid and then introduces the effect factors of photovoltaic output. Based on the history data of the 100 kWp photovoltaic power station and the statistical method, the paper qualitatively and quantitatively analyzes the photovoltaic output performance; finally puts forward the PV output power evaluation index. The conclusions of this study will provide powerful data references for follow-up studies and have practical value.