Advanced Materials Research Vols. 860-863

Abstract: Author constructed ARIMA model and GARCH model to predict the output power of the 4 wind turbine generators (A, B, C, D) and the total output power of the 4 and 58 wind turbine generators. Whats more, by comparing the results of two methods, it shows that the result of GARCH model is more accurate than ARIMA model in short-term prediction.

Abstract: In the emergency management of power system, there are many uncertain factors, such as wind power of the generation side and electric vehicle charging of the demand side. Firstly, the probability statistics model of PEVs charging demands was established, which considered the random factors of the probability distribution of PEVs charging. Then, we used scenarios generation and reduction techniques to predict the output of wind generators. The uncertainty of wind power was described by scenarios set. On this basis, the dispatch model considering PEVs charging and wind power was proposed. Finally, simulation results on the 5-generator system indicated the effectiveness of the proposed method. The synergistic dispatch model considering wind power and PEVs charging can effectively improve the utilization of wind power and the safety and economic benefits of the power system.

Abstract: The accuracy of wind power forecast is important to the power system operation. A new prediction model is proposed based on cloud reasoning and wind rate vector , combining with the current and the historical change rule of wind speed, using the change rule of wind speed in a period of time to forecast the power gradient in a point-in-time, The wind turbine power prediction is discussed based on power gradient and power eigenvalue. Simulation results on the case study of historical wind speed and generated power data in some area in China demonstrate that the proposed methodology can improve the accuracy of wind speed forecast and has practical value, especially for the wind turning point.

Abstract: With the requirement of grid security and special facts of wind power, enhancing the capacity of wind power abortion and connection becomes a major problem. How to optimize peak regulation to abort more wind power without too much water abandoned in flood season, is the major problem of hydropower optimization. In this paper, considering wind power as an influencing factor, we optimize hydropower generating operation: hydropower optimization model is established respectively in flood season and non-flood season, using Petri net to describe. At last, the test results on an actual reservoir show that when operating the reservoir with the consideration of wind power abortion, the capacity of peak regulation of hydropower can be fully dug out, which is of great significance in helping large-scale wind power to connect to the grid.

Abstract: Large-scale wind power integration constituted great challenges for the power system operation and dispatching, due to the volatile and peak-reversal nature of wind power.The multi-objective optimization model of the wind farm combined with pumped-storage was studied to solve the problem.An optimization model for wind-storage combined operation was established, aiming at tracking load changes ,improving wind power economic benefits and peak shaving benefits, using improved multi-objective particle swarm optimization.The optimization calculation attempted to reduce volatility of the remaining load after removal of wind-storage joint output and increase economic benefits of wind farrms. Through the optimization calculation the wind farm and storage plant scheduling values of each time are available. The calculation example shows that the model and method are conducive to large-scale wind power integration and have a certain practicality and effectiveness.

Abstract: The wind speed simulation model was given in this paper, combined with the power system analysis software (PSD-BPA) transient calculation of wind generator models, it implemented the wind speed disturbance of wind farms and the entire network voltage analysis. Combining the practical power grid in china, research on the power grid voltage fluctuation of the level after the large-scale wind farms integrated the system, and relevant the conclusions: In the process of wind disturbance, there is no angle stability of synchronous generator in the system, doubly-fed induction generator could emit and absorb reactive power, and thus could be able to maintain voltage stability.

Abstract: The direct-drive permanent-magnet synchronous generator (PMSG) system with full power converter can achieve wind maximum power point tracking (MPPT) in wide range variation of wind-speed. In this paper an operating characteristic of PMSG is investigated, a MPPT strategy based on hill climbing method for PMSG are present. Simulation and experimental results show that the controllers can extract maximum wind power in good dynamic performance.

Abstract: VSC-HVDC is one of the proven solutions to the transmission problem of offshore wind power and the study of converter is the key technology. Mean value model of converter is introduced. The paper puts forward a method that can simplify the complex converter which is based on IGBT into a mean value model to improve the simulation speed. Through the simulation in Mat lab, the accuracy and high efficiency of simplified model are verified. The results show that the simplified model is feasible.

Abstract: In this study, the thermoelectric power generation (TEG) module is used to recover waste heat from a downdraft gasifier. The performance and optimal operating temperature of TEG module are studied at different locations on the surface wall of catalyst reactor. The simulation model of downdraft gasifier is performed by using the Fire Dynamics Simulator (FDS), its appropriate for the low-speed, thermally-driven flow simulation with an emphasis on incomplete combustion process. The results demonstrate that the simulation temperature of catalyst reactor surface is around 200°C~300°C which is used to convert heat into electricity by TEG module. In summary, the TEG modulus power per unit area can reach 857W/m² with temperature difference of 140°C and output power attain at least 2.04kW if TEG modulus is applied on the improved downdraft gasifier system (IDGS).

Abstract: Biomass gasification is one of the most promising technologies to exploit energy from renewable biomass. In this paper, brief introduction of the mechanism of biomass gasification technology and the application status of biomass gasification was described in detail. The research progress of biomass gasification technology in China is reviewed. Finally, the features of these technologies are analyzed and the problems that the biomass gasification technology needs to solve and the research direction of this technology are pointed out.