考虑新能源功率不确定性与波动性的微网经济调度

发布时间：2018-11-18 06:16

【摘要】：随着智能电网的快速发展,微网为分布式电源提供了集成的平台,具有较大的技术、经济和环境效益。微网受新能源功率不确定性与波动性的影响,其可调度性、稳定性、经济性很难得到保证。为了使微网可靠、经济地运行,有必要考虑功率备用并协调微网内的可调节单元对微网进行经济调度。为减小新能源功率不确定性与波动性的影响,本文在微网经济调度中引入备用功率机会约束条件,并采用序列运算理论对不确定性变量建模以高效率处理机会约束条件。分别对并网微网及孤立微网的经济调度进行研究。首先,建立了负荷及新能源功率预测误差的不确定性模型。采用概率性序列描述风电、光伏及负荷功率预测误差的联合离散概率分布,为在调度过程中考虑新能源功率不确定性奠定基础。其次,建立了微燃机、蓄电池、可平移负荷、弹性负荷及可切除负荷的调度模型。改进了蓄电池放电深度模型,更恰当地表示蓄电池的充放电成本。然后,考虑新能源功率不确定性先后建立了并网微网及孤立微网日前经济调度模型,对孤立微网建立了日内短期滚动调度模型,进行多时间尺度调度进一步减小功率预测误差的影响。采用机会约束理论将新能源不确定性以旋转备用约束的方式融入调度模型。其中并网微网调度考虑分时电价;孤立微网内考虑需求侧灵活性负荷的互动。考虑经济性、环保性与可靠性构建了以系统运行成本最低为目标的调度模型。最后,为了改善优化算法的收敛性能,本文将遗传算法和粒子群算法结合,并引入专家经验逻辑策略对最优解修正,还将多个变量解耦优化,另外以功率不平衡的时段为中心进行局部小步长随机搜索。针对备用需求和不平衡功率分别设置特殊的粒子。通过微网算例对本文提出的模型、方法进行了分析和验证。结果表明,本文所提模型能够在减小新能源功率不确定性与波动性影响的同时保证微网经济运行,对并网微网及孤立微网经济调度具有一定的参考价值。
[Abstract]:With the rapid development of smart grid, microgrid provides an integrated platform for distributed power generation, which has great technical, economic and environmental benefits. Due to the uncertainty and fluctuation of new energy power, it is difficult to ensure the schedulability, stability and economy of microgrid. In order to make the microgrid run reliably and economically, it is necessary to consider the power reserve and coordinate the adjustable units in the microgrid for economic scheduling. In order to reduce the influence of uncertainty and volatility of new energy power, this paper introduces the spare power chance constraint condition in the microgrid economic scheduling, and uses the sequence operation theory to model the uncertain variable to deal with the opportunity constraint condition efficiently. The economic scheduling of grid-connected microgrid and isolated microgrid is studied respectively. Firstly, the uncertainty model of load and new energy power prediction error is established. The probabilistic sequence is used to describe the joint discrete probability distribution of wind power, photovoltaic and load power prediction errors, which lays the foundation for considering the uncertainty of new energy power in the scheduling process. Secondly, the dispatching models of micro gas turbine, battery, translational load, elastic load and removable load are established. The discharge depth model of battery is improved, and the charge and discharge cost of battery is more appropriately expressed. Then, considering the uncertainty of new energy power, the economic scheduling model of grid-connected microgrid and isolated microgrid is established, and the short-term rolling scheduling model of isolated microgrid is established. Multi-time scale scheduling can further reduce the influence of power prediction error. The opportunity constraint theory is used to integrate the uncertainty of new energy into the scheduling model by rotating reserve constraints. Time-sharing pricing is considered in grid-connected microgrid scheduling, and interaction of demand-side flexible load is considered in isolated microgrid. Considering economy, environmental protection and reliability, a scheduling model aiming at the lowest operating cost of the system is constructed. Finally, in order to improve the convergence performance of the optimization algorithm, the genetic algorithm and particle swarm optimization are combined, and the expert empirical logic strategy is introduced to modify the optimal solution, and several variables are decoupled and optimized. In addition, the local small step size random search is carried out at the time when the power imbalance is taken as the center. Special particles are set for reserve demand and unbalanced power respectively. The model and method proposed in this paper are analyzed and verified by a microgrid example. The results show that the proposed model can not only reduce the uncertainty and volatility of new energy sources, but also ensure the economic operation of microgrid, which has some reference value for economic scheduling of grid-connected microgrid and isolated micro-grid.
【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

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