Hierarchical Optimal Scheduling of Active Distribution Network Considering Flexible Energy Storage System

At present, power grid companies around the world are actively promoting the input of wind power, photovoltaic and energy storage systems, and the modernized power system presents a multi-type unit composite situation. In this paper, a coordinated scheduling strategy based on flexible output of energy storage is proposed to solve the problem caused by power fluctuation of wind and photovoltaic units and loads. The core of this strategy is the energy storage charge and discharge control based on the comprehensive economic index decision of system power fluctuation. First of all, the model considers the demand-side flexible load and actual energy storage as generalized energy storage resources, and makes full use of the flexible and fast charge and discharge capability of energy storage to reduce the peak-valley difference of the system, improve the flexibility of the system, and reduce the pressure of thermal power units. The lower control mainly realizes the active support of the power output of the thermal power unit and integrates it into the coordinated control system. Coordinate up and down output to achieve overall collaborative control. The model makes full use of the output characteristics of all kinds of resources, makes the energy storage cooperate with all kinds of units, realizes the coordinated scheduling of all kinds of resources, improves the intake of new energy in the system, and reduces the operating cost of the system. Finally, an IEEE 30-node system is used as an example to verify the effectiveness of the model proposed in this paper.