Assessment of Optimal Power Generation Mix Considering Extensive Variable Renewable Energy and Nationwide Power Interchange through Tie Lines

This paper evaluates the optimal power generation mix considering massive deployment of variable renewable energy and regional power interchange. Japan has initiated the feed‐in‐tariff (FIT) and expected the significant introduction of PV and wind power for energy self‐sufficiency and climate change. However, wind power resources in Japan are concentrated mainly in Hokkaido and the Tohoku region, which are remote from electricity‐consuming areas such as Tokyo, and facilitating the considerable deployment of wind power requires the establishment of inter‐regional power transmission lines. Against these backgrounds, we develop an optimal power generation mix model including regional electricity exchange as a large‐scale linear programming model with 10 million variables and 30 million constraints. The calculation results show that regional grid expansion encourages wind power installation in the Hokkaido and Tohoku regions for power supply to the Tokyo area, where PV power and stationary batteries are alternatively replaced. Grid expansion too promotes the shift of PV installation to the Kyushu and Shikoku regions, which have longer sunshine duration, and interchangeably mitigates PV deployment in other regions through the transport of PV power from those two regions.     

风电场风功率实时预测效果综合评价方法

超短期风电功率预测对含大规模风电的电力系统安全经济运行有着重要意义。但目前对预测结果的评价均停留在常规统计学指标上,缺乏合理的评价体系来评价某特定风电场所选取预测模型的优劣。简述了目前风电功率预测结果评价指标的不足,提出一种基于预测误差评价和预报考核等指标的风电场输出功率实时预测效果评估方法,为不同地区风电场根据其风电输出功率变化的特点,选择预测模型以及风电场输出功率预测效果的工程检验提供依据。最后,利用吉林省某风电场实测数据,采用该评估方法对不同预测模型的实时预测结果进行分析评价,实现了该风电场不同预测模型间的择优,验证了该评价方法的指导价值。     

计及风电的电网调度与控制架构分析

近年来我国的风电快速发展,局部地区的风电穿透率已经较高,这给传统的电网有功、无功调度与控制系统带来了很大的挑战。分析和总结风电的基本特性,包括波动性、不完全可预测性、低可控性等,以及我国风电一些特殊性如集中开发、远距离传输和直接接入主网等。详细分析了风电接入后需要对传统调度与控制系统做的改进工作,以及计及风电的调度与控制系统的整体框架。研究认为,在有功方面应按照三次、二次、一次频率控制的顺序开展研究与应用,在无功方面则应按照一次、二次、三次电压控制的顺序。同时也讨论了有功、无功调度与控制在发展路线上存在不同之处的内在原因。     

弃风供暖模式下风电接纳能力评估及效益分析

弃风供暖是解决风电接纳难题的有效途径,可缓解“三北”地区弃风严重问题。首先介绍储热式电采暖接纳弃风的运行模式,然后基于时序生产模拟方法建立弃风供暖模式下风电接纳能力评估模型,并以某省级电网为例,对不同电采暖运行模式下风电接纳能力进行评估分析,最后,基于中国现有弃风供暖模式和结算模式,定量分析了热电厂、风电场、电网企业、全社会各方经济主体利益以及全社会碳减排情况。案例分析结果表明,弃风供暖不仅可以提高风电接纳能力,还具有良好的环境效益,但是其提高的风电接纳的空间有限,且除绑定风电场之外的其他经济主体的收益不明显。     

Output power leveling of wind turbine generators using pitch angle control for all operating regions in wind farm

Effective utilization of renewable energies such as wind energy instead of fossil fuels is desirable. Wind energy is not constant and windmill output is proportional to the cube of the wind speed, which causes the generated power of wind turbine generators (WTGs) to fluctuate. In order to reduce the output power fluctuation of wind farms, this paper presents an output power leveling control strategy for a wind farm based on both the average wind farm output power and the standard deviation of the wind farm output power, a cooperative control strategy for WTGs, and pitch angle control using a generalized predictive controller (GPC) in all WTG operating regions. Simulation results using an actual detailed model for wind farm systems show the effectiveness of the proposed method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 158(4): 31– 41, 2007; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20448     

Output power control of wind turbine generator by pitch angle control using minimum variance control

Effective utilization of renewable energies such as wind energy as a replacement for fossil fuels is highly desirable. Wind energy is not constant and wind generator output is proportional to the cube of the wind speed, which causes the power output of wind turbine generators (WTGs) to fluctuate. In order to reduce output power fluctuations of wind farms, this paper presents an output power leveling control strategy for wind farms based on both the mean and the standard deviation of wind farm output power, a cooperative control strategy for WTGs, and a pitch angle control method using a generalized predictive controller (GPC) intended for all operating regions of WTGs. Simulation results using an actual detailed model for wind farm systems show the effectiveness of the proposed method. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(2): 10–18, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20247     

风力发电机组的有功控制研究

阐述了随着风力发电技术的迅速发展,以风能为基础的风力发电在全球的应用越来越广泛,风力发电在电力能源中所占的比例也越来越高。提出了由于风能的随机性和偶然性,使风力发电并网运行时产生很多技术问题,如有功调节能力差、电能质量差等,这些已成为制约风力发电大规模发展的主要问题。因此,研究含双馈风力发电机组的有功-频率调节对风电大规模利用具有非常重要的现实意义。以IEEE-9节点为例,介绍了双馈风电机风能捕获原理,提出风力发电机的有功调节-调频控制策略,并通过仿真验证了控制策略的有效性。     

同一控制区两级调度风电实时协调控制策略

新能源场站普遍存在点多面广、单场容量相对较小的特点,因此部分电网虽按同一控制区运行,但选择将新能源场站控制权下放,形成风电资源两级控制现状。为协调常规能源与风电运行,最大程度消纳风电,通过将下级调度风电整体等效为上级调度的自动发电控制(AGC)虚拟机组,提出同一控制区两级调度风电实时协调控制架构,并投入实际运行。上级调度根据电网当前运行状态、负荷超短期预测和风电实际出力及预测,每5min滚动计算得到电网内各个下级调度的风电发电指标,经余缺调剂后,下发给下级调度风电AGC执行。在大风季、供暖期的运行结果表明,采用所述的两级调度实时协调控制方案后,达到了京津唐地区风电增发的效果。     

含大规模风电的高压直流送端系统多源协同调频策略

针对含大规模风电的高压直流送端系统异步联网情况下频率易越限问题,提出了一种基于预测模型的多源协同调频策略。分析风电渗透率及高压直流外送功率占比对频率调整的影响,对不同扰动下各种调频措施的协调配合进行探讨。在长时间尺度上考虑高压直流输电的区域控制偏差约束,优化设置风电机组和火电机组的旋转备用容量;在短时间尺度上考虑电力电子器件的快速可控性,动态调整风电机组及高压直流输电的协同调频参数,使系统频率运行在合理水平。将预测模型得到的频率偏差根据大小进行分区,对不同区域采用不同的调频策略,保证送端系统的旋转备用容量合理及频率动态响应指标合规。基于PSCAD/EMTDC平台搭建含风电高压直流送端系统模型,仿真结果验证了所提策略的有效性及准确性。     

电力市场环境下含风电机组的配电网无功优化

电力市场环境下,合理考虑无功成本,有利于配电网无功功率资源的最优利用。本文从降低含网损、设备损耗和无功成本在内的综合成本的角度出发,研究含双馈感应风力发电机DFIG(doubly-fed induction generator)的配电网无功优化调度方法。首先,通过研究DFIG功率特性,对DFIG输出功率进行区域划分,建立无功分区计价模型;其次,分析了风速波动对DFIG无功最大出力影响,基于平均风速预测曲线,给出改良风速计算方法;最后以改进IEEE 14节点系统为算例,采用改进遗传算法优化求解。仿真计算结果表明,本文所提无功优化模型和方法具有合理性。