面向一次调频的炉-机-网协调控制方法研究

With the increase of the proportion of new energy in the power system, the pressure of the frequency regulation of the thermal power units is increased.But with the development of the generators for electric power systems, the capacity of installed supercritical and ultra-supercritical units is increasing in China. Without considering the properties of the boiler in primary frequency regulation, it would cause great resistance for the units with large installed capacity and high parameters when they participate in primary frequency regulation. Furthermore, that would threat the secure and stable operation of power systems. In order to solve the problem and let the generator and the grid to reach a win-win situation; i.e. fulfilling the requirement of the secure operation of power grid as well as making the units with large installed capacity and high parameters keep secure and efficient operation. Through considering the boiler, steam turbine, and power grid as a whole controlling object, it will have great practical significant to develop a new controlling method of primary frequency regulation.Taking the properties of installed supercritical and ultra-supercritical units into account, this project develops the primary frequency regulation problem into a coordination controlling problem. Moreover, in consideration of the differences of the boiler dynamic properties among different generators, we explore a multi-objective optimization controlling algorithm, which is observing the price as well as the safety of power units and the security of the power grid operation. This would reduce the cost of frequency regulation, as well as meeting the requirements of primary frequency regulation of thermal generator units; thus reaching a win-win situation for the generator and the grid.

随着电力系统中新能源比例的提高，使得火电机组调频的压力增大。但随着电力系统电源侧的发展，我国超临界和超超临界机组装机容量越来越大。如果在一次调频控制中不考虑锅炉的特性，将会给大容量高参数火电机组参加一次调频带来很大阻力，不利于电力系统安全稳定运行。如何解决矛盾让网源双赢，在满足电网安全运行要求的同时，又能够让大容量高参数发电机组安全高效的运行，把锅炉、汽轮机和电网看做一个控制对象来研究新的一次调频控制方法具有重要的应用价值。本项目考虑超临界及超超临界机组的特点，将一次调频问题发展成一种炉-机-网协调控制问题，考虑不同发电机组的锅炉动态特性的差异性，研究兼顾单元机组经济性、安全性及电网运行安全性的多目标优化控制算法，使得火力发电机组在满足电力系统一次调频要求的基础上，大幅度降低机组侧的调频代价，达到网源双赢的目的。

新能源的入网比例逐渐增大使得传统火电机组面临机遇和挑战。超临界机组在网源协调面临矛盾的背景下需要提高其运行效率和经济性。本项目计及机组侧与网侧双侧影响，提出了有助于超临界机组积极参与电力系统调频的综合控制策略，达到了网、源双赢的效果。. 首先，本项目建立了用于调频分析的超临界机组模型。依据直流锅炉的能量、质量、动量方程，建立能反映锅炉能量动态的非线性模型。在此基础上，基于超临界机组的物理特性，建立了包含直流锅炉、凝汽式汽轮机在内的单元机组模型，利用动态特性仿真讨论了超临界机组控制量和被控量之间的耦合关系。. 其次，依据网源能量状态制定了炉-机-网协调控制策略。为了使网源能量相协调，本项目定量分析锅炉能量偏差与电力系统功率偏差，在汽轮机功率给定处增加了反映锅炉能量与系统需求的修正量，并针对不同的电网频率和不同的锅炉主蒸汽压力设计不同的修正量。基于模型预测控制，本项目通过给区域控制偏差中添加额外修正量来在线预测、调整区域频率参考值，从而提高了超临界机组的调频效果。. 再次，建立了炉-机-网协调控制方法的定量综合评价指标。在机炉侧，定量研究了新的控制方法对超临界机组主要设备寿命和应力的影响；在网侧，定量研究了新的控制方法对CPS和SCPS指标的改善。并基于向量夹角余弦法建立了炉-机-网协调综合评价指标体系，得到了全面在线评价新的控制方法对超临界机组的整体贡献。. 最后，评估了风电对电网调频能力和超临界机组的影响。证明了风电渗透率的提升会降低区域系统的CPS指标考核结果，同时会降低超临界机组的SCPS指标考核结果。对于超临界机组的安全性，证明了风电渗透率的提升会增大超临界机组主汽压波动程度，威胁机组乃至整个系统的安全运行。对超临界机组参与风功率消纳的控制策略进行了探讨，通过仿真证明了该策略不仅能够增强机组在高风电渗透率下的稳定性，同时能够提升机组的调频能力，有助于提高机组所在区域的风功率消纳水平。

内容获取失败，请点击重试