含高渗透分布式光伏的增量配电网日前优化调度方法

Day-ahead optimal scheduling method for incremental distribution network with high penetration of distributed photovoltaic

针对装有高渗透率分布式光伏和用户侧储能的增量配电网日前调度问题,综合考虑配电站有载调压变压器抽头动作、静止无功补偿装置投切、用户侧光伏变流器无功补偿和储能装置充放电等调控手段,基于支路潮流模型建立了以增量配电网运营商日前运行总费用最小为目标的优化调度模型。由于潮流约束中存在电压平方项和电流平方项,目标函数的网损部分存在电流平方项,所以原模型是二次约束二次规划模型(Quadratically Constrained Quadratic Programming,QCQP)。通过线性化和二阶锥松弛,将原始NP难问题转化为混合整数二阶锥规划模型(Mixed Integer Second Order Cone Programming,MISOCP)。为了保证二阶锥松弛精度,提出计算配电网最优潮流的多时段割平面约束,将其加入到每次迭代优化中求解,直至松弛误差减小到预定范围。最后用实际算例验证了调度方法的有效性。

Aimed at the day-ahead scheduling problem for incremental distribution network with high penetration of distributed photovoltaic and energy storage system at user side,an optimal scheduling model is established based on branch flow model.The model minimizes the total operating cost of the incremental distribution network operator and takes into account the adjustment of on load tap changer,static var compensator,reactive power control of the PV converter and charge and discharge of the energy storage system.The original model is a Quadratically Constrained Quadratic Programming(QCQP)due to voltage square and current square in the power flow constraints and current square in the loss part of the objective function.By linearization and second order cone relaxation,the original NP hard problem is transformed into a Mixed Integer Second Order Cone Programming(MISOCP).In order to ensure the precision of cone relaxation,a multi-period cutting plane constraint is proposed to calculate the optimal power flow in the distribution network,and it is added to each iterative optimization until cone relaxation error is reduced to a predetermined range.Finally,the effectiveness of the proposed scheduling method is verified by a simulation example in a practical project.