Cooperative Scheduling of Source-Load-Storage for Microgrids with Electric Springs

Since in microgrid, distributed power sources are random and fluctuating, and loads and energy storage devices are complex, these characteristics make the microgrid scheduling problem exceptionally complex. In the process of microgrid dispatching, to reduce economic costs and improve voltage stability, we propose a coordinated planning model of microgrid source-load-storage with electric spring (ES). The ES is connected in series with non-critical loads to form smart loads, and through the use of smart loads, distributed power sources, loads and energy storage devices in the microgrid are simultaneously dispatched together. The objective function of the scheduling model is divided into two parts. The first part is the optimal economic cost, including the cost of charging and discharging energy storage, the cost of power purchase, the cost of wind and light abandonment, the cost of reliability and the additional cost corresponding to the introduction of ES; the second part is the optimal voltage balance of the microgrid, i.e., the minimum voltage deviation. In the process of model search, a model solving method considering load demand is proposed to quantitatively analyze the proposed energy optimization model and find the optimal scheduling scheme. Results show that the model can reduce the operating cost and optimize the voltage level of the distribution network under various scenarios, thus verifying the correctness and effectiveness of the proposed model.