面向可再生能源并网系统的灵活性评估方法

Flexibility Evaluation Method for Power System Towards Grid-connected Renewable Energy

在高比例可再生能源接入的电力系统背景下,为满足系统的负荷需求及其变化,需要对电力系统的灵活性水平进行评估。为此,提出了固有灵活性与运行灵活性两种指标评价机组的灵活性水平,其中,固有灵活性指标从运行上下限和爬坡能力两方面评估机组的灵活性水平,运行灵活性指标在机组组合方案确定的基础上评估机组的灵活性水平。在固有灵活性与运行灵活性基础上,对电力系统的灵活性进行评估,并用IEEE-118节点系统来验证所提灵活性评估方法的有效性。结果分析表明,系统负荷趋势与运行灵活性存在一定规律,提高机组性能可显著提高系统灵活性水平。

Under the background of power system with high-proportion integrated renewable energy,in order to meet the load demand of the system and its changes,the flexibility level of power system needs to be evaluated.In this pa⁃per,two indicators of inherent flexibility and operation flexibility are proposed to evaluate the flexibility level of units.The first one evaluates the flexibility level of units from aspects of operation limits and the climbing ability,and the sec⁃ond one is based on the unit combination plan.On the basis of inherent flexibility and operation flexibility,the flexibili⁃ty of power system is evaluated.In addition,an IEEE 118-node system is used to verify the effectiveness of the pro⁃posed flexibility evaluation method.The analysis of results shows that there is certain pattern between system load trends and the operation flexibility,and improving the unit performance can significantly increase the flexibility level of power system.