1、可再生能源优先调度深化研究国网能源研究院2013 年 10 月执行摘要大力发展风电、太阳能等可再生能源是国家落实节能减排、实现能源可持续发展战略的重要举措。目前多数国家一般采用对风电进行价格补贴、 优先调度风电等政策性支持的方式鼓励风电发展。我国先后出台了中华人民共和国可再生能源法、 节能发电调度办法、中华人民共和国可再生能源法修正案等，制订了可再生能源优先调度的具体办法。这些法律法规制定了我国可再生能源优先上网发电的原则和规范， 对促进可再生能源的发展有重要意义。随着我国风电等可再生能源的进一步发展，大规模风电的调度运行问题日益突出。在此情景下，受美国能源基金会委托，国网能源研究院开展可再生
2、能源优先调度深化研究，旨在进一步研究和探讨适合我国国情的可再生能源优先调度具体方式和方法，提高电网对大规模可再生能源的运行消纳能力。课题重点从发电计划制定方面，研究其对可再生能源优先调度的促进作用。 课题分析了我国可再生能源优先调度面临的形势和问题以及当前可再生能源调度运行管理现状，梳理了国外典型风电富集地区调度机构在促进可再生能源调度运行方面的实践经验，以及采用的模型方法。在分析我国重点风电省份电源特点和风电运行特点的基础上，提出适应我国可再生能源优先调度的中长期与短期相结合的发电计划模型；基于模型，通过实证分析，研究了风电功率预测、不同机组组合策略对系统可再生能源优先调度的影响，提出了促进
3、可再生能源优先调度的机组组合策略。课题主要研究成果包括如下四个方面：（1）提出基于可再生能源优先调度的发电计划制定思路课题在分析我国重点风电地区电源特点与风电运行特点的基础上，提出基于可再生能源优先调度的机组组合建模思路。建立基于我国可再生能源优先调度的机组组合模型，要充分以下我国电源结构和风电运行的以下特点：一是常规电源以燃煤机组为主，机组启停时间长、启动成本高，与波动性较强的风电协调运行能力较差；二是风电场技术水平参差不齐，风电功率预测精度普遍不高，对风电功率预测信息的利用需要兼顾促进风电消纳与保证系统安全；三是冬春季是风电大发期，恰与火电供热期重合，由于供热机组“ 以热定电”运行管理方式
4、，机组调 峰能力有限。基于此，基于可再生能源优先调度的发电计划制定应包含以下特点：一是采用长期发电计划与短期发电计划相结合，在更 长时间尺度内安排燃煤机组启停计划，避免因为风电波动造成的燃煤机组频繁启停；二是充分利用最新风电功率预测信息，滚动修正发电计划，分阶段最大限度消纳风电；三是充分考虑风电功率预测的不确定性以及系统电源特点，安排合适的系统备用容量，保证系统运行安全。整体实施思路如下图所示：周 发 电 计 划 制 定第 i 周全 年 8 7 6 0 小 时周 风 电 出 力 预 期周 负 荷 预 测备用容量信息启 停 较 慢 机 组 的周 启 停 计 划日发电计划制定日 发 电 计 划 滚
5、 动日 发 电 计 划 滚 动. . .日 风 电 出 力 预 期日 负 荷 预 测备 用 容 量 信 息所 有 常 规 机 组 启 停 计 划 和 发电 计 划 ， 风 电 出 力 计 划更 新 日 风 电 出 力 预 期更 新 日 负 荷 预 测更 新 日 风 电 出 力 预 期更 新 日 负 荷 预 测所 有 常 规 机 组 滚 动 启 停 计 划 和 发 电计 划 ， 风 电 出 力 滚 动 计 划所 有 常 规 机 组 滚 动 启 停 计 划 和 发 电计 划 ， 风 电 出 力 滚 动 计 划更 新 备 用 容 量 信 息更 新 备 用 容 量 信 息第 j 天一 一 一 一一 一
6、 一 一 一 一一 一 一 一一 一 一 一 一 一（2）总结国外可再生能源优先调度实践经验与模型课题深入分析和总结了美国德克萨斯州、丹麦、西班牙等国外典型风电富集地区调度机构在促进可再生能源调度运行方面的实践经验，以及采用的模型方法。国外调度机构在促进可再生能源调度运行方面的主要实践经验包括：1）通过适应风电特点的电力市场机制，风电参与电力市场中日前、日内等各个发电计划制定环节，促进风电优先调度；2）不断提高风电功率预测水平，为风电场参与电力市场并及时调整发电计划提供重要技术支撑；3）相对灵活的电源结构，有效提升系统调峰能力，为风电等可再生能源实现优先调度提供保障；4）跨国跨区互联电网为风电
7、等可再生能源实现跨地区优先调度创造条件；5）积极开展需求侧管理，有效辅助风电优先调度、保证电网安全稳定运行。从国外现有的含可再生能源调度模型来看，多为适用于系统中长期规划的模型，如 Balmorel 模型和 WILMAR 模型，不能直接 应用于运行阶段。模型中均考虑了大规模风电出力，对含大规模风电的电力系统调度运行研究有很好的参考价值。但考虑到我国电源结构特点、风电消纳问题等的特殊性，无法直接应用于我国风电富集地区的电力系统运行分析。（3）建立基于可再生能源优先调度的机组组合模型基于可再生能源优先调度的发电计划制定思路，课题建立基于可再生能源优先调度的机组组合模型，包含以下特点：一是通过风电出
8、力容量系数以及风电功率预测信息等，将风电出力纳入发电计划制定，为风电预留发电空间；二是采用长期机组组合与短期机组组合相结合的两阶段机组组合，统筹安排火电机组和风电发电计划，最大限度消纳风电；三是采用基于概率的备用容量配置方式，综合考虑机组停运概率与风电出力不确定性，并根据系统机组特点不同（如启停时间长短不同），灵活调整备用配置量；四是在备用容量约束中考虑风电提供备用容量的可能性，如考虑采用弃风电量提供上调备用等。（4）可再生能源优先调度的机组组合策略实证研究课题结合系统案例，设计多个分析场景，基于建立的可再生能源优先调度模型研究促进可再生能源优先调度的机组组合策略。课题设计的 4 种机组组合策
9、略分别为基础场景 1、基础场景 2、长期机组组合、长期机 组组合与短期机组组合相结合。其中，基础场景 1 与基础场景 2 在制定发电计划时均不考虑风电功率预测，且采用确定型备用容量配置方案；长期机组组合以及长期机组组合与短期机组组合结合方案考虑风电功率预测，且采用概率型备用容量配置方案。通过建立三类分析场景，对以下问题进行分析：一是不同机组组合策略对系统运行的影响；二是不同风电接入水平对系统运行的影响；三是不同CO2 价格水平对系统运行的影响。案例分析结果表明：（一）基于风电功率预测将风电纳入发电计划，并且考虑燃煤机组启停特点，在更长的时间尺度内制定发电计划（如一周），可以提高系统风电接纳能力
10、；（二）当系统风电装机容量较高时，由于风电功率预测的不确定性，仅采用长期机组组合策略（如周计划）制定发电计划时可能导致系统出现少量切负荷。若在长期机组组合发电计划（如周计划）的基础上，根据最新的日风电功率预测信息，滚动修正发电计划，则将有效提高系统运行的可靠性。 （三）随着系统风电装机比例的增加，在不采取其他措施的情况下，系统弃风比例增加，但由于风电替代更多的燃煤机组发电，系统 CO2 排放量降低。 （四）较高的 CO2 价格水平对提高系统风电利用率和降低 CO2 排放量有促进作用，但在系统常规机组 CO2 排放系数相近的情况，机组发电序位和出力计划受 CO2 价格水平的影响不大。Execut
11、ive summaryDeveloping renewable energy resources such as wind power and solar energy are is an important measure to implement the national energy conservation and sustainable energy development strategy. At present, most countries generally set supportive policies such as subsidies and priority disp
12、atch of wind power to encourage the development of wind power. China has promulgated the “China Renewable Energy Law“, “Energy Saving Generation scheduling Approach “, “The Peoples Republic of China Renewable Energy Law Amendment“, etc. that regulated the generation priority of renewable energy. The
13、se laws and regulations formulated the principles and norms of priority access of renewable power generation to the power grid, and are of great significance to promote the development of renewable energy. With the future development of renewable energy such as wind power in China, the large scale i
14、ntegration of wind power is increasingly becoming an important issue and wind power curtailment is a big concern. Commissioned by the U.S. Energy Foundation, the State Grid Energy Research Institute carried out further study of renewable energy priority dispatch, which aims to further explore ways a
15、nd approaches of renewable energy priority dispatch that are suitable to implement in China. This study focuses on the wind curtailment issue in China, and explores ways of renewable energy priority dispatch with better generation scheduling methods and more flexible generation fleet. First, the cur
16、rent situation and problems facing Chinas renewable energy dispatch, as well as the current operation and management of renewable dispatch are analyzed. Priority dispatch models for renewable energy worldwide are investigated. Second, characteristics of the generation portfolios and wind power are a
17、nalyzed and a unit commitment model based on priority dispatch of renewable energy is established. Using the model, a typical case study is conducted to analyze the impact of wind power forecast and different unit commitment strategies on renewable energy priority dispatch. Unit commitment strategie
18、s that promote the priority dispatch of renewable energy are proposed. Thirdly, the roles and potentials of three types of gas turbines in facilitating renewable energy dispatch are studied. Finally, conclusions and suggestion for future policies and management measures are presented. Main achieveme
19、nts of the study are as follows:(1) Ideas for generation scheduling based on renewable energy are proposed.Characteristics of the generation portfolios and wind power are analyzed and ideas for generation scheduling based on renewable energy are proposed. The following characteristics of wind-rich p
20、ower systems in China need to be considered when making renewable energy priority dispatch based generation schedules. 1) Conventional generators are mostly coal-fired generators, which take a long time to startup and incur high startup cost, and do not coordinate well with the variable wind generat
21、ion. 2) Wind power forecast accuracy is generally low, a reasonable amount of reserve is needed to ensure system reliability. Though most wind farms in China have the capability to provide wind power forecast, compared with international forecast performance, there still needs improvement. Consideri
22、ng the inflexible nature of coal-fired generators, utilization of wind power forecast in generation scheduling needs more attention fitting in as much wind as possible in generation schedules with wind power forecast information as compared with procuring a reasonable amount of reserve to consider w
23、ind power forecast uncertainty. 3) Windy season (winter and spring) coincides with heating season. The operation mode of CHPs electricity generation determined by heat generation, limits the regulating range of CHPs. The idea for making generation schedules considering the above characteristics is i
24、llustrated with the following figure.W e e k l y G e n e r a t i o n S c h e d u l e W e e k iW h o l e Y e a r : 8 7 6 0 h o u r sW e e k l y w i n d o u t p u t e x p e c t a t i o nW e e k l y l o a d f o r e c a s tS p i n n i n g r e s e r v e p r o c u r e m e n tO n / o f f s t a t u s o f s
25、l o w c o n v e n t i o n a l u n i t sD a i l y G e n e r a t i o n S c h e d u l eD a i l y G e n e r a t i o n R o l l i n g S c h e d u l eD a i l y G e n e r a t i o n R o l l i n g S c h e d u l e. . .D a i l y w i n d p o w e r f o r e c a s tD a i l y l o a d f o r e c a s tS p i n n i n g r
26、 e s e r v e p r o c u r m e n tG e n e r a t i o n s c h e d u l e s o f a l l c o n v e n t i o n a l u n i t s , a n d w i n d p o w e r g e n e r a t i o n s c h e d u l eU p d a t e d w i n d p o w e r f o r e c a s tU p d a t e d l o a d f o r e c a s tU p d a t e d w i n d p o w e r f o r e c
27、 a s tU p d a t e d l o a d f o r e c a s tR o l l i n g s c h e d u l e s o f a l l c o n v e n t i o n a l u n i t s , a n d w i n d p o w e r g e n e r a t i o n s c h e d u l eR o l l i n g s c h e d u l e s o f a l l c o n v e n t i o n a l u n i t s , a n d w i n d p o w e r g e n e r a t i o
28、n s c h e d u l eU p d a t e d s p i n n i n g r e s e r v e p r o c u r e m e n tU p d a t e d s p i n n i n g r e s e r v e p r o c u r e m e n tD a y jS t a g e 1 一L o n g r a n g e u n i t c o m m i t m e n tS t a g e 2 :S h o r t r a n g e u n i t c o m m i t m e n t(2) International experience
29、s in power system operation with large scale renewable energy integration are summarized.Operation experiences with large scale renewable energy integration in ERCOT (US), Denmark and Spain are analyzed. Operation models used in the international environment are also investigated. Typical experience
30、s summarized are: 1) Participation of wind power in day-ahead, intra-day and real time markets through electricity market mechanism largely enhances priority dispatch of wind power; 2) Continued improvement in wind power forecast performance provides key technical support for wind power dispatch; 3)
31、 flexible generation mix and large regulation capability guarantees wind power priority dispatch; 4) trans-regional power grid interconnection makes it possible to accommodate wind power over a large area; 5) Demand side response provides effective support for system security during emergency condit
32、ions. Typical models for wind power dispatch are Balmorel and WILMAR, but they are mainly used for long term planning studies. Operational models considering characteristics of wind-rich power systems in China are needed.(3) A unit commitment model based on priority dispatch of renewable energy is e
33、stablished.The unit commitment model established in the study contains the following features.1) Wind power forecast is used in making generation schedules, which gives more room for wind power generation compared to the current practice, which do not consider wind power forecast in making generatio
34、n schedules.2) A three-stage process is used in unit commitment. The three stages are long range unit commitment, short range unit commitment and final dispatch. In long range unit commitment, limited information about wind power is used but rough plan of conventional generation is provided. The on/
35、off status of slow start units will be fixed after this stage. In short range unit commitment, updated wind power forecast information is used to update generation schedules, which improves generation schedules as wind power forecast is more accurate closer to real time. In the final dispatch stage, on/off levels of all conventional generators are fixed, and
