风电场的继电保护

大规模风电接人系统对电力系统电能质量的影响较大.风能的随机性和不可控性,使风电占系统容量的份额增大时,向系统提供的短路电流也越来越大,因此,风电保护配置对电网的影响也是重要的.文章对风电系统保护进行了论述,分析了风电对电网继电保护的影响,使用MATLAB的动态仿真工具SIMULINK、对包含风电场的单机无穷大电力系统发生联络线故障时进行动态仿真.通过分析双馈发电机不同故障类型下的故障电压、电流曲线,指出风电场应采用的适应性保护.     

The effect of spatial dispersion of wind power plants on the curtailment of wind power in the Greek power supply system

To meet the national target of 29% for electricity production from renewable energy sources by 2020 in Greece, effective implementation of massive wind power installed capacity into the power supply system is required. In such a situation, the effective absorption of wind energy production is an important issue in a relatively small and weak power system such as that of Greece, which has limited existing interconnections with neighboring countries. The curtailment of wind power is sometimes necessary in autonomous systems with large wind energy penetration. The absorption or curtailment of wind power is strongly affected by the spatial dispersion of wind power installations. In the present paper, a methodology for estimating this effect is presented and applied for the power supply system of Greece. The method is based on probability theory, and makes use of wind forecasting models to represent the wind energy potential over any candidate area for future wind farm installations in the country. Moreover, technical constraints imposed by the power supply system management, the commitment of power plants and the load dispatch strategies are taken into account to maximize the wind energy penetration levels while ensuring reliable operation of the system. Representative wind power development scenarios are studied and evaluated. Results show that the spatial dispersion of wind power plants contributes beneficially to the wind energy penetration levels that can be accepted by the power system. Copyright © 2009 John Wiley & Sons, Ltd.     

On the wind power rejection in the islands of Crete and Rhodes

Crete and Rhodes represent the two biggest isolated power systems in Greece. The energy production in both islands is based on thermal power plants. The annual wind energy rejection percentage is calculated for Crete and Rhodes in this paper. The rejected wind energy is defined as the electric energy produced by the wind turbines and not absorbed by the utility network, mainly due to power production system's stability and dynamic security reasons. A parametric calculation of the annual wind energy rejection percentage, in terms of the installed wind power, the power demand and the maximum allowed wind power instant penetration percentage, is accomplished. The methodology takes into account (i) the wind power penetration probability, restricted by the thermal generators technical minima and the maximum allowed wind power instant penetration percentage over the instant power demand; and (ii) the wind power production probability, derived by the islands' wind potential. The present paper indicates that isolated power systems which are based on thermal power plants have a limited wind power installation capacity—in order to achieve and maintain an adequate level of system stability. For a maximum wind power instant penetration percentage of 30% of the power demand, in order to ensure an annual wind energy rejection percentage less than 10%, the total installed wind power should not exceed the 40% of the mean annual power demand. The results of this paper are applicable to medium and great size isolated power systems, with particular features: (i) the power production is based on thermal power plants; (ii) the power demand exhibits intensive seasonal variations and is uncorrelated to the wind data; (iii) the mean annual power demand is greater than 10MW; and (iv) a high wind potential, presenting mean annual wind velocity values greater than 7·5ms^?1, is recorded. Copyright © 2007 John Wiley &Sons, Ltd.     

基于最优滚动控制域的储能控制策略

针对风电场预测功率与实际功率不匹配以及风力发电不确定性问题,提出一种以补偿风电预测误差和平抑风电波动为目标的储能控制策略。该策略以先进控制理论为基础,结合储能补偿预测区间和储能平抑风电波动区间,提取考虑储能运行成本的储能最优滚动控制域。首先,针对储能补偿预测误差目标,制定储能控制策略,提取允许误差内的储能补偿区间;其次,考虑风电功率波动要求及荷电状态（SOC）约束,采用模型预测控制求解出储能滚动控制序列,确定储能平抑区间。最后,考虑储能运行成本,将补偿区间和平抑区间相结合,制定储能最优滚动控制区间,以此为基础确定储能容量。以中国新疆某风电场为例,对该文提出的储能控制策略与传统控制策略进行对比验证,验证所提策略的可行性和有效性。     

Effect of energy storage on variations in wind power

Irregularities in power output are characteristic of intermittent energy, sources such as wind energy, affecting both the power quality and planning of the energy system. In this work the effects of energy storage to reduce wind power fluctuations are investigated. Integration of the energy storage with wind power is modelled using a filter approach in which a time constant corresponds to the energy storage capacity. The analyses show that already a relatively small energy storage capacity of 3 kWh (storage) per MW wind would reduce the short‐term power fluctuations of an individual wind turbine by 10%. Smoothing out the power fluctuation of the wind turbine on a yearly level would necessitate large storage, e.g. a 10% reduction requires 2–3 MWh per MW wind. Copyright © 2005 John Wiley & Sons, Ltd.     

我国风力发电的现状与展望

阐述了风能是清洁的可再生能源,将为能源结构调整和环境保护做出重大贡献。在对风电装机容量、风电场分布及相关政策进行统计的基础上,分析了中国风力发电现状,提出了风力发电亟待解决的问题,展望了我国风力发电的前景。     

风电与储能联合运行的碳减排效果

在全球能源危机和环境污染的背景下,风电—储能联合运行系统对电力行业的节能减排有重大影响。将风电和储能变量同时引入供给函数均衡模型来模拟风电—储能联合运行系统提供的基荷电量,并在此基础上通过情景分析分别估算了发电企业在风电系统、储能系统及风电—储能联合运行系统3种情景下的污染气体排放量。结果表明,各发电企业在利益最大化目标的驱使下将不断增加储能量,使得联合运行系统比单独的风电或储能系统具有更高的排放量,且排放量的大小受储能容量的影响。     

Framework design of a hybrid energy system by combining wind farm with small gas turbine power plants

Owing to the stochastic characteristic of natural wind speed, the output fluctuation of wind farm has a negative impact on power grid when a large-scale wind farm is connected to a power grid. It is very difficult to overcome this impact only by wind farm itself. A novel power system called wind-gas turbine hybrid energy system was discussed, and the framework design of this hybrid energy system was presented in detail in this paper. The hybrid energy system combines wind farm with several small gas turbine power plants to form an integrated power station to provide a relatively firm output power. The small gas turbine power plant has such special advantages as fast start-up, shutdown, and quick load regulation to fit the requirement of the hybrid energy system. Therefore, the hybrid energy system uses the output from the small gas turbine power plants to compensate for the output fluctuation from the wind farm for the firm output from the whole power system. To put this hybrid energy system into practice, the framework must be designed first. The capacity of the wind farm is chosen according to the capacity and units of small gas turbine power plants, load requirement from power grid, and local wind energy resource distribution. Finally, a framework design case of hybrid energy system was suggested according to typical wind energy resource in Xinjiang Autonomous Region in China.     

Framework design of a hybrid energy system by combining wind farm with small gas turbine power plants

Owing to the stochastic characteristic of natural wind speed, the output fluctuation of wind farm has a negative impact on power grid when a large-scale wind farm is connected to a power grid. It is very difficult to overcome this impact only by wind farm itself. A novel power system called wind-gas turbine hybrid energy system was discussed, and the framework design of this hybrid energy system was presented in detail in this paper. The hybrid energy system combines wind farm with several small gas turbine power plants to form an integrated power station to provide a relatively firm output power. The small gas turbine power plant has such special advantages as fast start-up, shutdown, and quick load regulation to fit the requirement of the hybrid energy system. Therefore, the hybrid energy system uses the output from the small gas turbine power plants to compensate for the output fluctuation from the wind farm for the firm output from the whole power system. To put this hybrid energy system into practice, the framework must be designed first. The capacity of the wind farm is chosen according to the capacity and units of small gas turbine power plants, load requirement from power grid, and local wind energy resource distribution. Finally, a framework design case of hybrid energy system was suggested according to typical wind energy resource in Xinjiang Autonomous Region in China.     

对我国风电发展战略的冷思考

我国风电发展迅速,计划2010年风电装机容量要达到3500×10^4kW,2020年达到1.5×10^8kW。据IEA预测,2030年世界能源供应仍以化石能源为主,其比重由2006年的80.8%下降到80.4%;2030年世界发电能源结构也以化石能源发电为主,其比重由2006年的74%下降到73%。中国到21世纪中叶传统化石能源仍将居绝对优势地位。因此在可再生能源和新能源的开发过程中,不要急于求成,片面追求能源和电源结构优化不可取。我国未来要依靠核电和新能源发电,但需要通过对其技术经济的进一步研究,才能确定主要靠核电还是风电、太阳能发电或生物质能发电。目前我国风电发展的主要问题是对风电的技术要求起点低,技术路线不对,从国外引进了落后的风电技术。为了我国风电的健康发展,必须加快风电合理利用的研究,包括风电储能和风电直接利用的研究。     

Stochastic security-constrained operation of wind and hydrogen energy storage systems integrated with price-based demand response

Because of highly increasing energy consumption, environmental issues and lack of common energy sources, the use of renewable energy sources especially wind power generation technology is increasing with significant growth in the world. But due to the variable nature of these sources, new challenges have been created in the balance between production and consumption of power system. The hydrogen energy storage (HES) system by storing excess wind power through the technology of power to hydrogen (P2H) and delivering it to the electricity network through hydrogen-based gas turbine at the required hours reduces not only wind alternation but can play an important role in balancing power production and consumption. On the other hand, power consumers by participating in demand response (DR) programs can reduce their consumption at peak load or wind power shortage hours, and increase their consumption at low-load or excess wind power hours to reduce wind power spillage and system energy cost. This paper proposes a stochastic security constrained unit commitment (SCUC) with wind energy considering coordinated operation of price-based DR and HES system. Price-based DR has been formulated as a price responsive shiftable demand bidding mechanism. The proposed model has been tested on modified 6-bus and 24-bus systems. The numerical results show the effect of simultaneous consideration of HES system and price-based DR integrated with wind energy on hourly generation scheduling of thermal units. As a result there is some reduction in wind generation power spillage and daily operation cost.     

鄱阳湖区风能资源精细化评价需求分析

结合江西省风电发展规划分析了风电开发对风能资源精细化评价的需求,设计了风能精细化评价指标,并提出了解决方案.     

风力发电项目多目标决策研究

随着风力发电技术的不断发展,风力发电已成为我国重点发展的可再生能源产业。如何科学有效地选择风电项目,既关系到投资商的切身利益,也关系到风能的有效开发利用。文章利用层次分析法,在分析风电项目关键影响因素的基础上,建立多目标决策的风电项目评价模型,以帮助开发商选择合适的风电场项目,促进风能的开发利用。     

A comparison of methodologies for monthly wind energy estimation

Monthly wind energy estimations obtained by means of three different methodologies are evaluated. Hourly wind and wind power production data measured at five wind farms in the Northeast of Spain within the period spanning from June 1999 to June 2003 were employed for this purpose. One of the approaches is based on the combined contribution of the hourly wind speed frequency distribution and the corresponding power production. Several alternatives to represent the empirical wind power versus wind speed relationship are considered and their impacts on the error of monthly energy estimations assessed. Two more approaches derive monthly energy estimates directly from monthly wind values: one uses the theoretical power curve to obtain interpolated monthly wind power production values and the other consists in a simple linear regression between the observed wind speed and wind power monthly pairs, which serves as an approximation to the global power curve. The three methodologies reproduce reliably the total monthly wind energy. Results also reveal that linearity is a reasonable assumption for the relation between wind speed and power production at monthly timescales. This approach involves a simplification with respect to other standard procedures that require finer temporal resolution data. Copyright © 2009 John Wiley & Sons, Ltd.     

Review on combined wind power generation and energy storage systems

储能系统由于能够实现电能的时空平移,具有响应速度快,规模化等优点,是改善风电波动性,提高其并网能力的有效手段,构建风储联合发电系统成为目前研究重点.简单介绍了风电并网对电力系统的影响及不同类型电池储能技术的发展现状,给出了部分国内外风储联合发电系统的示范工程,并分析了平滑风电功率波动,跟踪计划出力曲线和削峰填谷3种主要运行方式,重点阐述了目前风储联合发电系统控制策略和储能容量配置研究现状,对进一步开展风储联合发电系统的研究进行了展望,指出经济性仍然是制约储能技术应用的关键问题之一,提高包含储能单元的风储联合发电系统的经济性是今后的研究重点.     

基于蚁狮算法的风电集群储能容量配置优化方法

随着风电渗透率提高,风电并网对电网安全稳定运行影响更加显著。风电配备储能可有效改善风电出力波动性和不确定性,增强可调度性。该文建立以风电集群联合储能系统售电收益最高为优化目标的模型,采用蚁狮算法算法进行求解,得到风电集群功率备用、储能功率和容量最优配置方案,对比蚁狮算法、遗传算法和粒子群算法优化结果,分析储能电池单位成本和寿命对优化结果影响。最后以中国东北某风电集群作为算例,验证了所提算法与模型的有效性。     

开发风力发电设备的战略及途径分析

开发利用洁净能源和可再生能源,改善以煤炭为主的能源结构已成为我国能源建设实现可持续发展战略的重要措施。目前,国内外以风能力代表的新能源的开发利用方兴未艾。通过对国内外风电发展现状的调查研究及国内风电市场发展前景的分析与展望,提出发展风电制造业的一些具体措施,加速能源结构的调整。     

计及不确定性的多类型发电机组联合调度优化模型

为了促进可再生能源并网,解决可再生能源机组在内的多类型发电机组联合优化调度问题,引入全额收购可再生能源发电,由火电机组提供备用、允许适度弃风,由火电机组提供备用以及水火机组联合提供备用的可再生能源发电三种不同方案。首先构建了涵盖风、光伏、水力机组的可再生能源机组发电处理模型;再结合设定的三种方案组建了多类型发电机组节能调度优化模型;最后,基于基础数据,得出该节能调度优化模型的发电系统总煤耗、备用煤耗、系统发电成本、启停成本、弃风量及弃水量等关键指标的优化效果,对多类型发电机组联合调度优化具有一定的指导意义。     

Exploitation and utilization of the wind power and its perspective in China

Wind energy, as a reliable, natural and renewable electrical power supply, produces no emissions and so it is an excellent alternative to conventional, more heavily polluting fuels in the long term based on the worldwide concern about the environment and energy supply. Wind energy resources in China are affluent, but its distribution are uneven, centralized, and far from both the utility and the high electricity demand markets. This made China's onshore wind power development have such characteristics as large scale, high centralization and far transmission, which is different with that in Europe, where the characteristics are even distribution, decentralized. In past two decades, considering the economic, technical and environmental benefits of wind power, China has given priority to its development. Besides the dramatic growth of large scale grid-connected wind power, household-scale wind power has been used most successfully in remote rural regions in China. Therefore, the development of wind power will be of great importance to alleviate the energy crisis and environmental pollution resulting from the rapid economic growth of China in the future. In this paper, the current development of wind energy utilization in China is investigated, and some critical barriers are discussed. Finally, the perspective of wind energy utilization is presented, where focuses are placed on seven wind power bases.     

Contribution to the improvement of voltage profile in electrical network with wind generator using SVC device

Wind energy is a growing renewable energy because of its several advantages; this has changed dramatically with more wind energy penetrating the conventional power network. The influence of wind generators on the power quality is becoming an important issue; non-uniform power production causes variations in system voltage and frequency, therefore, a wind farm requires high reactive power compensation. The advances in high power semiconductor devices have led to the development of Flexible AC Transmission System (FACTS). This paper presents the impact of wind energy integration on voltage stability and the goal of FACTS devices such as Static Var Compensator (SVC), which is a power electronic switch, to control the reactive power injection according to the thyristor firing angle, introduced as a state variable in power flow and combined with the nodal voltage magnitudes and angles of the power network for iterative solutions, thereby regulating the bus voltages.