论风机系统中应用风电滑环的重要性

风电作为清洁能源,他们的应用受到了国家的大力扶持。在我国工业不断发展的大背景下,风电滑环的工业设计与生产水平也在不断的提高。当下,我国新能源与新材料行业的发展都被受瞩目,风电滑环作为较大的商用能源,已经成为国家政策支援的重点发展对象。在这样的行业发展背景下,提高风电滑环的精密度和工艺必不可少,本文主要介绍了风电滑环的应用以及未来发展。

离网型风力发电的应用前景

离网型小风电以其节能环保,机动性好,安装便捷等优点深受广大农牧民的欢迎,在大风电飞速发展的同时,离网型小风电可以作为必要的补充。该文简要分析了离网型小风电的现状和小风电的优势,展望了离网型风力发电的应用领域。

电弧光保护在风力发电机中的应用研究

随着全球变暖的加剧,经济发展所带来的环境保护问题越来越突出,中国也相应地制定了“碳达峰、碳中和”目标,发展清洁能源已是必要的途径。近几年,风力发电机单机容量不断增加,安装地点也从陆上发展到了海上,针对海上大容量风电机组提出了一种新的保护方案,该保护方案是将弧光传感器及电流测量综合应用于海上风力发电机的保护中去,提出了单判据和双判据方案,提高了海上风电机组运行的安全性。

柔性直流输电技术在海上风电中的运用分析

随着社会经济的发展,人们对电力方面的需求逐渐增加,传统的火力发电越来越难以满足实际需要,行业的重心逐渐向海上风电等发电模式转变。近年来,柔性直流输电技术在海上风电中得到了广泛应用,其具有换相成功率高、无需进行换流站间通信、能够对无源网络供电等诸多优势。基于此,简单分析该技术在海上风电中的未来发展趋势,并对该技术在海上风电中的实际应用进行讨论,以供参考。

Analysis of Offshore Wind Power： Application to Southern Thailand

This paper presents an analysis of a pre-feasibility study of a 10 MW offshore wind power project in Nakhon Si Thammarat province, southern Thailand. The wind speeds at the hub heights of large scale wind turbine generators （WTG）, i.e. 80-100 m, were extrapolated using monthly mean wind shear coefficients and the l/7th exponent. Using WAsP 9.0, the annual energy production from several models of offshore wind farms using different WTG was analyzed. The capacity factor and the cost of energy were then computed. Using best available estimates, the analysis shows that the estimated annual mean offshore wind speeds at 80-100 m were in the range of 6.4 and 8.3 m/s. The annual energy production by the wind farm from nine models of wind turbine generators were in the range of 20-39 GWh/year, corresponding to a capacity factor in the range of 26-46%, while the cost of energy was 12-15 US cent/kWh.

Analysis on Application of Wavelet Neural Network in Wind Electricity Power Prediction

Wind electricity power has fluctuation, and accurate and reasonable wind electricity power prediction is very important for solving wind electricity network and combination. This paper takes an analysis of a lot of actual data of a certain wind electricity field. Through wavelet neural network and time series method rolling, it can predict the overall power of wind electricity field. The result shows that for the original data of sampling time length and large sampling frequency, the model constructed by this paper has very good prediction effect. Because of the fan installation position, wind electricity fan flow effect and other random factor influence, wind electricity field overall power and single unit power distribution have difference. Through comparing with the time series parameters, it puts forward that single wind electricity unit power has smooth effect for overall power of wind electricity field. Finally, it summarizes the prediction effect and puts forward some reasonable suzestions for wind electricity network troblems.

Research and Application of Probability Distribution of Wind Power Fluctuation Characteristics

The fluctuation characteristics is the inherent property of wind power.Through analysis of a large number of wind t＇anns based on measured data,we find it describes the best probability distribution of wind power fluctuation for the mixed Gauss distribution of two components,and try to carry out the physical interpretation of two components.Further discussion is between the probability distribution of fluctuating wind power time difference and whole relationship.It is found that the two have basic similarity.Through comparing the different time level data quantified losses the information of wind power fluctuation,quantitative determination of the degree of impact prediction.We can summarize and understand of wind power fluctuation,constructing instance from the wind farm construction and monitoring prediction two aspect recommendations to overcome the adverse effects of wind power fluctuations on the power grid operation.

State-Model Based Time-Domain Diagnosis of Internal Faults for Permanent Magnet Synchronous Machine Wind Application

Upon occurrence of an internal fault on the PMSM （permanent magnet synchronous machine）, the topology of the stator is amended causing structural imbalances due to the change of the connection within the windings. In this work, a state model of internal faults of the PMSM is developed. This model is in the （abc） reference frame. The modeling approach is based on the assumption that each stator phase is replaced by two major and minor sub-windings. This model is used subsequently in the residual generation for diagnosis. The fault indicators are obtained by the projection in parity space and estimated using the Luenberger observer. A scenario of fault inter-turn by the short-circuit occurring between phase （a and b） is validated by simulation.

Application of Wind Generation on Weak Networks Considering Potential System Limitations Due to Transients and Faults

Limited resources are available on the application of wind generation systems interconnected to weak powemetworks. With the need to further interface DG （distributed generation） including WG （wind generation） to weak networks, it is necessary to establish a means of determining what is the most efficient quantity of WG that can be applied in order to maintain stability in the network. This paper establishes a concept that can be applied to weak networks. The aim is to estimate how much WG can be installed on weak networks as well as establishing characteristic responses to generation loss without and with faulted conditions. The main contribution is a thorough understanding of weak network limitation proved to be the most critical parameter in these calculations.

Fuzzy Logic Controlled Dual Active Bridge Series Resonant Converter for DC Smart Grid Application

Over the last few years, smart grids have become a topic of intensive research, development and deployment across the world. This is due to the fact that, through the smart grid, stable and reliable power systems can be achieved. This paper presents a fuzzy logic control for dual active bridge series resonant converters for DC smart grid application. The DC smart grid consists of wind turbine and photovoltaic generators, controllable and DC loads, and power converters. The proposed control method has been applied to the controllable load＇s and the grid side＇s dual active bridge series resonant converters for attaining control of the power system. It has been used for management of controllable load＇s state of charge, DC feeder＇s voltage stability during the loads and power variations from wind energy and photovoltaic generation and power flow management between the grid side and the DC smart grid. The effectiveness of the proposed DC smart grid operation has been verified by simulation results obtained by using MATLAB and PLECS cards.

Magnetic Gearbox with an Electric Power Output Port and Fixed Speed Ratio for Wind Energy Applications

Mechanical gearboxes are typically employed with doubly-fed induction generatur-based wind turbines. The main drawback of this solution is the gearbox＇s reliability and maintenance. Using magnetic gearbox in conjunction with the doubly-fed induction generator is an emerging alternative being promoted by the research community which maintains the reduced size doubly-fed machine and overcomes the mechanical gearbox problems reported by field experience. This paper proposes a novel magnetic gearbox configuration in which a conventional planetary magnetic gearbox is equipped with n-phase coils fitted around the ferromagnetic pole-pieces to extract output electrical power. The turbine mechanical power is thus divided into mechanical power to drive the electrical generator and extra electrical power that can be diverted into a storage system to perform the power leveling function. The proposed configuration can also be used to freely modify the power-speed characteristic as seen by the electrical generator, a highly needed feature for grid frequency support.

Transient stability probability of a power system incorporating a wind farm

An analytical approach for probabilistic evaluation of transient stability of a power system incorporating a wind farm is presented in this study. Based on the fact that the boundary of practical dynamic security region(PDSR) of a power system with double fed induction generators(DFIG) can be approximated by one or few hyper-planes in nodal power injection space, transient stability criterion for given configurations of pre-fault, fault-on and post-fault of a power system is to be expressed by certain expressions of linear combination of nodal injection vector and the transient stability probability(TSP) is further obtained with a much more simplified expression than the complex integral. Furthermore, considering uncertainties of nodal injection power including wind power and load, TSP is calculated analytically by Cornish-Fisher expansion, which can provide reliable evaluation results with high accuracy and much less computing time compared with Monte Carlo simulation. TSP and its visualization can further help operators and planners be aware of the degree of stability or instability and find critical components to monitor and reinforce. Test results on the New England 10-generators and 39-buses power system show the method's effectiveness and significance for probabilistic security assessment.

Studies on a low Reynolds number airfoil for small wind turbine applications

In contrast to large horizontal axis wind turbines (HAWTs) that are located in areas dictated by optimum wind conditions, small wind turbines are required for producing power without necessarily the best wind conditions. A low Reynolds number airfoil was designed after testing a number of low Reynolds number airfoils and then making one of our own; it was tested for use in small HAWTs. Studies using XFOIL and wind tunnel experiments were performed on the new airfoil at various Reynolds numbers. The pressure distribution, C p , the lift and drag coefficients, C L and C D , were studied for varying angles of attack, α. It is found that the airfoil can achieve very good aerodynamic characteristics at different Reynolds numbers and can be used as an efficient airfoil in small HAWTs.