计及风电相关性的区域间可用输电能力概率评估

大规模风电并网给电力系统区域间可用输电能力(available transfer capability, ATC)评估带来了新的挑战,为更加准确地评估高风电渗透率不确定性条件下的区域间ATC,文章提出了一种计及风电空间相关性的ATC概率评估方法。首先,利用条件概率原理对历史数据进行处理,并应用Copula函数对风电相关性进行建模;其次,区域间ATC的评估过程涉及到最大输电能力和现有输电协议的计算,因此提出一种ATC双层优化模型,在此基础上,利用Karush-Kuhn-Tucker(KKT)最优条件,双层模型即转化为均衡约束的数学规划(mathematica program with equilibrium constraint, MPEC)模型;再次,再将MPEC模型转化为混合整数二阶锥规划问题;最后,采用蒙特卡罗仿真对计及风电相关性的区域间ATC进行概率评估,并以IEEE 30节点系统为例,分析风电相关性对区域间ATC的影响,验证所提模型的正确性和有效性。

Probability Evaluation of Available Transfer Capability Considering Wind Power Correlation

Large scale wind power integration brings new challenges to the assessment of available transfer capability (ATC) of power system. In order to evaluate the ATC under the uncertain conditions of high wind power permeability more accurately, a method is proposed to evaluate the probability of ATC that takes the correlation of wind power into consideration. Firstly, the historical data are processed using the conditional probability principle and the wind correlation is modeled by the Copula function. Secondly, the evaluation process of ATC involves the calculation of the total transfer capability (TTC) and the existing transfer commitments (ETC), so this paper proposes a bi-level optimization model, on the basis of which, using the Karush-Kuhn-Tucker (KKT) optimal conditions, the bi-level model is transformed into mathematical program with equilibrium constraint (MPEC) model. Then, the MPEC model is transformed into a mixed integer second-order cone planning problem. Finally, the Monte-carlo simulation is used to evaluate the probability of inter-regional ATC, and the IEEE 30-bus system is used as an example to analyze the influence of wind power correlation on the assessment of inter-regional ATC and verify the correctness and validity of the proposed model.