考虑大规模风光分层接入的配电网多层协调无功优化方法

A multi-layer coordinated reactive power optimization method for a distribution network considering large-scale distributed wind-photovoltaic hierarchical access

大量风光新能源分层、多点接入给配电网运行带来了电压越限等负面影响,增加了不同电压等级无功协同优化的难度。兼顾不同电压等级调节需求,从模型降维等值的角度,提出了基于等值模型的配电网多层协调无功优化方法。该方法分别针对含有无功调节设备及没有无功调节设备的两种台区系统,利用神经网络对大量台区相关运行数据进行训练得到台区拟合模型,形成不可控和可控两种类型的台区等值模型,并用这两类拟合模型分别代替两类台区系统的物理模型,使台区以数据驱动的方式参与配电网无功优化,形成馈线物理模型和台区拟合模型组成的单一电压等级物数混合优化调度模型。将原多层无功优化问题转换为单层系统优化问题,再对该单层系统无功优化调度问题进行求解。该方法可降低配电网系统优化计算规模,从而减小计算量,以无功优化数学模型与数据驱动方法相结合的方式,实现配电网馈线-台区多层协调无功优化。通过算例验证了所提方法对于解决分布式风光分层接入所导致电压越限问题的可行性、有效性和优越性,能够保障配电网的经济安全稳定运行。

The large number of layered multi-point accesses of wind and solar energy sources has brought a negative impact of voltage limit to the operation of a distribution network.It also increases the difficulty of reactive power collaborative optimization of different voltage levels.Considering the regulation requirements of different voltage levels,a multi-layer coordinated reactive power optimization method based on equivalent model is proposed from the perspective of dimension reduction equivalence of the model.Considering two station systems,one containing reactive power adjustment equipment and one not,this method uses a neural network to carry on the training to the massive station area correlation operation data to obtain the station area fitting model,forming two types of uncontrollable and controllable platform equivalent models.These two fitting models are used to replace the physical models of the two types of station areas,enabling the station areas to participate in the reactive power optimization of the distribution network in a data-driven manner.This forms a single voltage level object number mixed optimization scheduling model composed of the feeder physical model and the station areas fitting model.The original multi-layer reactive power optimization problem is transformed into a single-layer system optimization problem,and then the single-layer system optimization scheduling problem is solved.It can reduce the scale of optimization calculation for distribution network systems,and combine reactive power optimization mathematical models with data-driven methods to achieve multi-level coordinated reactive power optimization of distribution network feeders and station areas.The feasibility,effectiveness and superiority of the proposed method for solving the problem of voltage over-limit caused by distributed wind-photovoltaic access are verified by an example.This helps to ensure the economic,safe and stable operation of the distribution network.