【作者】 静铁岩；

【导师】 李卫东；

【作者基本信息】 大连理工大学 ， 电力系统及其自动化， 2011， 博士

【摘要】 随着风电在我国各电网中并网规模的不断扩大,风电所具有的随机性、间歇性以及反调峰特性给电力系统有功平衡的各个方面都带来非常大的影响。在其中,低谷调峰能力不足所导致的大规模弃风浪费是当前电网面临的主要问题；而风电场脱网所造成的频率控制问题也值得关注。针对上述两个方面的问题,论文进行了较为系统和深入的研究,主要工作及成果如下：1.冬季供暖期,由于热电联产机组的调峰能力因供暖而下降,导致负荷低谷期间强迫出力过大,留给风电上网的空间严重不足,造成大量弃风。为此,在借鉴丹麦经验的基础上,提出了在我国电力系统中实行热电厂参与风电低谷调峰的设想,以东北电网为例论述了热电参与调峰对接纳风电的效益。分析表明,热电参与调峰是解决未来电网风电接纳能力不足的一个有效途径。进一步,还分析了三种可行的“热电解耦”技术方案,指出了实行热电参与调峰所面临的关键问题。2.为激励发电企业充分发掘其调峰潜力参与风电调峰,在充分考虑当前我国电力系统运营环境的基础上,提出了在现有上网电价制度下建立市场化的非常规调峰服务定价机制的构想。进而,通过对风电弃风机理的剖析,考虑现有的调峰管理模式,设计了风电参与的非常规调峰服务交易理论基本框架,并对其中的核心问题及解决方案进行了论述。分析表明,风电参与的非常规调峰服务市场,既可产生调峰价格信号,激励调峰并引导风电与调峰电源协调发展,还可保证电网经济运行,而且与现有风电扶持政策相兼容。3.为平抑风电的日间波动性,保障火电机组各日所承担尖峰负荷数量的稳定性,减少火电机组开停机调峰需求,提出了冬季枯水期水电一风电联合调峰运行策略,建立了以月为决策时间尺度、以周为决策时间间隔的滚动决策框架。理论分析和算例验证均表明,该联合运行策略不仅可有效平抑风电出力的日间波动性,使火电机组承担的日尖峰负荷保持稳定,从而保障火电开停机稳定性；还可利用水电的剩余容量与风电协调,充分利用风电电量,从而提高系统调峰能力、减少火电机组开机容量,提高电网运行经济性。4.大规模风电并网后,使得原有的低频减载方案存在安全隐患。为此,对风电出力的波动性和风电机组的低频保护对低频减载方案整定的影响进行了分析,论证了低频减载方案校核模型中单机改进为多机的必要性,提出了计入风电机组的影响的模型参数修『正方法,进而设计了大规模风电并网下的低频减载方案。最后,对传统方案和改进方案进行了仿真对比,结果表明,改进方案能更为有效地抑制系统频率下降,频率恢复效果更为良好。上述研究表明,对调峰问题而言,热电参与调峰是解决未来我国风电接纳的有效途径,其关键在于要有良好的调峰激励机制,而市场是最为有效的手段；水电——风电联合调峰运行也可以在一定程度上提高系统的调峰能力,从而提高系统接纳风电的水平。对频率控制问题而言,在设计低频减载方案时必须充分计及风电机组的影响,从而提高低频减载方案的可靠性。上述研究可为我国大规模风电并网后有功平衡问题的解决提供有益的参考。更多还原

【Abstract】 With more wind power being integrated into the power grid, its random and intermittent output has brought great impact on various aspects of active power balances. Among them, the main problem at present is massive wind power curtailment during valley periods due to lack of regulating abilities. Also, frequency control issues caused by trip-off of wind farms from grid are worth concern. The paper probes and discusses the above two issues systematically and in-depth. The main work and the results are as follows.1. All the CHP plants have been operated full load in winter to satisfy the heat demand, giving limited space for wind power to access the grid especially in the off-peak hours at night, which would result in large wind power curtailment when output of wind power is larger than the limited space. Based on the experience of Denmark, the conception of CHP plants reducing their electric outputs to offer more space for wind power in load valley periods is proposed. Then the benefits of accommodating wind power by applying this conception in Northeast China grid are analyzed and the results show its validity. Furthermore, three feasible technical schemes of decoupling heat-power constraints of CHP plants are analyzed, and the key issues of implementing CHP plants to regulate for wind power are discussed.2. To encourage generation companies fully exploiting their potentials of peak load regulation, the marketing pricing mode for unconventional peak load regulation service is suggested under the current power system operation environment of China, especially the current generation price regime. The mode intents to inspire generation companies regulating peak load voluntarily and to lead the wind farm developing rationally with the ability of peak load regulation of system. By anatomizing the mechanism of limiting the wind farms’ outputs, based on the current management pattern of peak load regulation services, the basic trading framework of unconventional peak load regulation service with participation of wind farms is designed, and then the core issues and corresponding possible solutions are discussed. Analysis shows that the wind farm participated peak load regulation service market has several merits. It can generate price signal for active peak load regulation and rational expansion of wind power with the system acceptance ability, and can ensure the economic operation of system, and is also compatible with the current policy for supporting wind power development. 3. To smooth the large fluctuations of wind power output on the inter-day scale, ensure the stabilization of daily peak load for thermal power, and reduce the inter-day start-up and shut-down times of thermal units, a new operation strategy, combining the hydropower with wind power to regulate the peak of load, is advised with a weekly rolling decision framework. The theoretical analyses and numerical examples show that the combined operation of hydro and wind power generation system can not only smooth the large inter-day fluctuations of wind power output in daily peak hours and thus ensure the stabilization of daily peak load and start-up and shut-down operations for thermal power, but also improve the system peak-load regulating ability by utilizing the energy of wind power and the unused capacity of hydropower sufficiently and thus reduce the start-up capacity of thermal units and improve the operation economy.4. With the large-scale wind power integration, the original under--frequency load shedding scheme cannot meet design requirements any more. Thus, the impacts of fluctuating wind power and low frequency protection for wind turbine generator on under-frequency load shedding scheme are analyzed. And then the under-frequency load shedding scheme under large-scale wind power integration is designed. The analyses show that it is necessary to improve the traditional single machine model into multiple machines model. By considering the impact of wind turbines on the system model, a method of modifying the model parameters is proposed. Finally, the improved scheme is compared with the traditional scheme. The simulation results show that the improvement scheme can restrain the frequency falling effectively, and the effect of the recovery of frequency is better.The study shows that for the peak load regulation problem, the participation of CHP plants is an effective way to solve the wind power curtailments in future. The key is to have a good incentive mechanism, while the market is the most effective means. The combination operation of the hydropower with wind power can improve the peak load regulating ability of the system to some extent; thereby enhance the wind power accommodation level of the system. For the frequency control problem, the impact of wind turbines must be taken full consideration in the design of under-frequency load shedding scheme to ensure its reliability. The study would provide a useful reference for the solution of active power balance problem after the large-scale wind power integration in China.更多还原