含风电系统的抽水蓄能与直流联络线优化调度研究

发布时间：2018-05-10 14:00

本文选题：置信区间 + 风电消纳　；参考：《华北电力大学》2017年硕士论文

【摘要】：近年来,风力发电技术飞速发展,电力系统中风电装机容量也不断提升,纵然风力发电具有清洁、低成本、可再生等诸多优点,但风电入网消纳的问题仍亟待解决。一方面,自然条件下风速具有随机性和波动性,风电的预测精度较低,电力系统需要预留更多的备用容量来平抑风电预测误差,这样既增加了电力系统的备用容量成本,又使火电机组的调峰深度降低,在严峻的情况下,甚至需要采取弃风措施才能保证系统正常运行。另一方面,我国风力资源区域分布不均,风力富集区域的风电与负荷之间反调峰特性更加明显,风电就地消纳困难,火电机组需要进一步减小出力甚至停机来消纳风电,不利于系统的经济稳定运行。为了深入探讨风电入网对电力系统产生的影响和提高风能利用率的措施,通过数学建模和求解的方式对含风电系统的优化调度问题进行研究。本文的具体分为以下几点:1)对风电的预测误差进行概率性分析,在一定的置信水平下对预测误差的置信区间进行估计,从而确定系统需要预留的最小备用容量。在此基础上,提出了置信区间的估计方法,即BP神经网络算法,与传统的Mont Carlo相比,该方法的计算精度更高,鲁棒性较好。2)分析抽水蓄能的运行机理,采用随机规划方法,建立风电-火电-抽水蓄能多源协调联合经济调度模型。为了提高模型求解效率,提出了一种部分整数变量的确定思路,来降低模型的非凸性。通过模型的求解分析不同置信水平下机组组合的结果、抽水蓄能的运行情况以及系统的经济性等。结果表明,置信水平越高,机组组合的结果越可靠,但高的置信水平在保证系统安全稳定运行的同时,增加了系统运行的负担,如抽水蓄能的运行时间、调峰机组数量和系统的经济成本等均会明显上升。3)以两区域互济供电系统为研究对象,提出了直流联络线三种运行模式,即固定运行、自由运行和离散化运行。建立了相应的数学模型来研究区域间风电调度的问题,同时提出了目标函数和约束条件线性化的方法。通过CLPEX进行模型求解,结果表明,直流联络线离散化运行方式的效果接近自由优化,离散化运行的优势在于充分发挥两区域互济作用的同时,有效地减少了联络线的调整频率,保证了系统稳定性。
[Abstract]:In recent years, with the rapid development of wind power generation technology, the installed capacity of wind power system is also increasing. Although wind power generation has many advantages, such as clean, low cost, renewable and so on, the problem of wind power receiving into the network still needs to be solved. On the one hand, the wind speed is stochastic and fluctuating under natural conditions, and the prediction accuracy of wind power is low, so the power system needs to reserve more reserve capacity to stabilize the prediction error of wind power, which not only increases the cost of reserve capacity of power system, In order to ensure the normal operation of the system, the peak shaving depth of thermal power units is reduced, and in severe cases, the measures to abandon the wind are even taken to ensure the normal operation of the system. On the other hand, the distribution of wind power resources in China is uneven, the backpeaking characteristic between wind power and load is more obvious in the area of wind power enrichment, and it is difficult for wind power to be absorbed on the spot. Thermal power generating units need to further reduce their output or even stop to absorb wind power. It is unfavorable to the stable operation of the system. In order to probe into the influence of wind power network on power system and the measures to improve the utilization rate of wind energy, the optimal dispatching problem of wind power system with wind power system is studied by mathematical modeling and solving. This paper is divided into the following points: 1) the prediction error of wind power is probabilistic analyzed and the confidence interval of prediction error is estimated at a certain confidence level so as to determine the minimum reserve capacity that the system needs to reserve. On this basis, a confidence interval estimation method, BP neural network algorithm, is proposed. Compared with the traditional Mont Carlo, this method is more accurate and robust. 2) the operation mechanism of pumped storage energy is analyzed, and the stochastic programming method is adopted. A combined economic dispatching model of wind power, thermal power and pumped storage energy is established. In order to improve the efficiency of solving the model, a method of determining partial integer variables is proposed to reduce the non-convexity of the model. By solving the model, the results of unit combination at different confidence levels, the operation of pumped storage energy and the economy of the system are analyzed. The results show that the higher the confidence level, the more reliable the unit combination results are, but the higher confidence level ensures the safe and stable operation of the system, and increases the burden of the system operation, such as the operation time of pumped storage energy. The number of peak-shaving units and the economic cost of the system will increase obviously. 3) taking the two region power supply system as the research object, three operation modes of DC tie-line are put forward, that is, the fixed operation, the free operation and the discrete operation. The corresponding mathematical model is established to study the problem of inter-region wind power scheduling. At the same time, the method of objective function and constraint linearization is proposed. The model is solved by CLPEX. The results show that the effect of discrete operation of DC tie-line is close to that of free optimization, and the advantage of discretization is to give full play to the role of the two regions and to reduce the adjusting frequency of tie-line effectively. The stability of the system is guaranteed.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM73

【参考文献】