基于Box-Cox变换结合多种算法的风电机组数据预处理方法研究

由于弃风限电、环境干扰等因素的影响,SCADA系统采集的原始数据中会存在异常数据,对原始数据进行精确有效的数据预处理,是后续故障预警工作的基础;基于SCADA系统采集的数据,对风电机组运行数据的预处理方法进行改进和研究,提出了一种将Box-Cox变换与以正态分布为前提的异常值清洗算法相结合的方法,对原始数据进行预处理;运用Box-Cox变换分别与Bin算法、肖维勒准则、狄克逊准则和格拉布斯准则相结合的方法进行数据预处理,经过实例验证:肖维勒准则的算法简单且检测时间短,但是对于异常数据的清洗效果较差;狄克逊准则和格拉布斯准则对于异常数据的清洗效果较好,但是处理时间较长,对大型风电场海量数据,这种方法的实用性较差;相比于其他算法,Bin算法的优势较为明显。

Flashover Probability of Wind Turbine Blade and Impact of Strong Electromagnetic Pulse from Lightning Strikes on Wind Turbine Safety

This paper systematically studies the flashover probability of wind turbine blade lightning arrester and the impact of strong electromagnetic pulses on the local and surrounding wind turbines during lightning strikes.The research results indicate that the flashover probability of direct lightning strikes by the wind turbine blade lightning arrester is almost negligible,and the strong electromagnetic pulse of wind turbine blade during lightning strikes has a serious impact on the electronic equipment of the machine,while the impact on the surrounding wind turbine is relatively small.At the same time,the calculation formula for the reflection of lightning current on the carbon brush between the wind turbine hub and the engine compartment during the flashing of the wind turbine blades is provided,and the calculation method for calculating the spatial gradient distribution of electromagnetic field intensity using Biot-Savart Law theorem is applied.The limitations of using wind turbine blades for lightning protection are pointed out,and a technical route for achieving wind turbine lightning safety is proposed,which can be used as a reference for wind turbine lightning protection technicians.

基于遗传算法的风光最优互补运行策略研究

为了充分考虑风光功率在不同时间空间尺度的各类特性,发挥风光发电的互补特性及其协同效应,提高风光系统的发电效率和经济效益,提出一种基于遗传算法的风光最优互补运行策略,该方法构建以功率平衡、运行成本最小为目标函数,以风光发电运行条件和风光发电最大功率变化量为约束条件的多目标优化模型,并采用带精英策略的非支配排序遗传算法对模型进行优化求解。

Analysis on Lightning Strike Cause of Directly Buried Optical Cable in Wind Farm and Its Prevention Methods

Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed.

Application of Comprehensive Lightning Interceptor in Highway Toll Station

Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll station is mainly based on the electrical geometry model-rolling ball method.Lightning rod or lightning belt is installed on the high pole lamp of the toll square and the ceiling of the toll island as a flash catching device to intercept lightning.The lightning rod is a section of metal conductor with the tip.From the process of the connection between up leader generated by the lightning rod and down leader of lightning,the lightning rod has the ability to attract the lightning rod,and can prevent lightning strike of the protected objects within a certain range.From the perspective of lightning protection methods and means,lightning protection plays an interception role against lightning discharge,also called interceptor.A large number of practice has proved that the lightning rod plays an important role in protecting the building structure from lightning damage.With the development of electronic information society,the limitations of lightning rod are more and more prominent,resulting in more and more lightning strike accidents.In 2019,China invented a new flash connection device-lightning interceptor that can overcome the limitations of lightning rod and has applied it on expressways,which has achieved remarkable results.In this paper,the physical parameters of lightning receiving process by the lightning interceptor and the lightning rod are compared,and the solution to prevent direct lightning strike at expressway toll station is proposed.

变围压循环荷载下饱和软黏土的变形特性

通过GDS双向振动设备对温州饱和软黏土在部分排水状态下进行了一系列变围压动三轴试验,系统地研究了循环偏应力与循环围压的耦合对加载期间土体变形规律的影响。试验结果表明:软黏土在循环加载期间的轴向应变和体应变均随着循环周次呈现先快后慢的增长趋势,且较高的偏应力幅值与较大的变围压条件η能促进轴向应变和体应变的发展。通过对比变围压与常围压下的累积轴向应变可知:当循环变围压导致循环平均有效主应力大于初始平均有效主应力时,累积轴向应变与变围压条件η呈线性关系;当循环平均有效主应力小于初始平均有效主应力时,累积轴向应变与η之间则不再呈线性关系。

强风事件识别及预报订正方法研究

以如东海上风电场升压站激光雷达测风资料为基础,提出了一种强风事件识别方法,设计并比较了三种预报强风事件识别方案。基于决策树和一元线性回归方法,分别开展了针对强风事件的订正方法研究。结果发现:三种预报强风事件识别方案中,等分位阈值方案明显更优,事件命中率达到76.1%,匹配时长命中率达到87.6%;采用消偏阈值方案和等分位阈值方案预报的强风事件时长会更接近观测强风事件时长;等分位阈值方案识别的事件基本可以覆盖到各次观测强风事件的全程;两个订正模型相对于模式预报都有一定提升与改进,其中决策树比一元线性回归模型更优,其平均绝对误差、相对误差和均方根误差明显更小。

南海湿热海上风电机组环境条件研究

海上风电机组在南海亚热带湿热海域会面对高温、高湿、高盐雾的严酷环境,对风电机组运行造成不利影响。本文针对南海海上风电机组进行1年环境条件监测,分析温湿度、盐雾等环境因素的变化规律,评价电气设备所处环境腐蚀性,对结构件涂层进行性能测试与可靠性评价,对风电机组运行、维护、防腐提供数据支撑。

基于最优增益系数的永磁直驱型风力发电机组控制策略仿真研究

依据三相直驱型风力发电机拓扑图建立数学模型,在此基础上搭建控制框图并建立仿真模型,仿真结果为仿真功率与理论功率差值均在5%以内,从而验证了仿真模型的准确性。利用仿真模型对定值最优增益系数和随空气密度自适应最优增益系数2种策略进行仿真,以验证最大风能利用系数和风力发电机输出功率受环境空气密度的影响关系。仿真结果表明,在空气密度自适应最优增益系数的控制策略下,最大风能利用系数和风力发电机的输出功率比定值最优增益系数控制策略均提升约1%。

海上风电出力特性及其消纳问题探讨

现阶段,风力发电有着较为广阔的发展前景,尤其是海上风电。为了保证海上发电作业的有效性,需要全面研究这一能源发电的具体情况,找出海上风电场工作期间的缺陷和不足,及时采取措施进行改进。基于此,分析了海上风电的出力特性、消纳问题,并提出了解决策略。

可再生能源等比补贴系数及投资估值模型研究

[目的]随着我国"碳中和、碳达峰"目标的提出,可再生能源发电企业面临着快速扩大装机规模,大力发展投资并购的诉求,在我国存量补贴资金缺口逐步增大的背景下,如何确定可再生能源项目的补贴收入,并采用合理方法对项目估值,一直是并购决策的难点。[方法]重点关注了2020年发布的补贴新政,测算了可再生能源存量补贴的兑付系数,基于多情景假设补贴现金流入的规模及时间。[结果]通过等比补贴系数测算及投资估值模型,明确了我国补贴缺口的收口时间及各年度的等比补贴系数,并基于可再生能源项目特点,研究选定最佳估值方法。[结论]通过估值模型对部分地区的海上风电和陆上风电项目进行了估值,为企业投资及并购提供了重要决策支撑。