提高关键负荷供电可靠性的交直流微网分布式能量优化管理策略

Optimal Management Strategy for Distributed Energy with Enhanced Power Supply Reliability of Critical Loads for AC/DC Hybrid Microgrids

交直流混合微电网具有较高的灵活性和可控性,能够为多种类型的分布式电源提供并网接口。然而,交直流微网中可再生能源占比较高,容易出现出力波动或出力不足等现象,难以保障关键负荷可靠供电;此外,交直流微网中分布式电源可能从属于不同运营主体,相互之间缺乏有效的信息交换,集中式管控较为困难。为此,提出提高关键负荷供电可靠性的交直流微网分布式能量优化管理策略,构建了微网分布式能量优化管理架构,建立以考虑微网负荷优先级的供电可靠性为优化目标、考虑各设备运行约束的能量优化管理模型,提出基于分布式模型预测控制的能量优化管理策略,并通过分布式次梯度算法求解。多个场景下的仿真分析表明,所提方法不仅可平抑可再生能源波动对负荷供电的影响、保障关键负荷的供电可靠性,还能有效保护微网设备隐私信息、满足交直流微网多运营主体环境下的负荷供电可靠性需求。

The AC/DC hybrid microgrid can provide grid-connected interfaces for various types of distributed equipment due to flexibility and controllability. However, the AC/DC microgrid usually contains a relatively high proportion of renewable energy, which is prone to output fluctuations or insufficient output. Reliable power supply of critical loads may not be ensured. Also, distributed devices in the microgrid may belong to different operating entities, and there is a lack of effective information communication between the operating entities, where centralized operation may not be applicable. To this end, we propose an optimal energy management strategy with enhanced power supply reliability of critical loads. An optimal management scheme for distributed energy is established, and an optimal model which aims to enhance the power supply reliability considering priorities of the microgrid loads and the operation limits of each device is developed. An optimal energy management strategy based on the model predictive control is designed, and a distributed subgradient algorithm is integrated. Simulation under various conditions shows that the proposed strategy not only suppresses the fluctuation of power supply caused by renewable energy sources and ensures the power supply reliability of critical loads, but also effectively protects the private information of microgrid’s devices and be suitable to AC/DC hybrid microgrids with multiple operating entities.