独立光储直流微网的稳定运行控制策略

Stable operation control strategy for an independent DC microgrid with photovoltaics and a storage system

为提升对太阳能等可再生能源的利用能力,并解决边远地区或小型系统的稳定供电问题,独立光储直流微网的稳定运行控制受到了研究者的关注。针对光储直流微网各元件的底层控制方面,提出了光伏MPPT和CV模式的统一控制方法。为保证光储直流微网在不同光照和储能电量条件下的稳定运行,将光储直流微网的工作模式分为三种,分别对应于光伏和蓄电池的不同元件底层控制方式。对于微网的控制方式,考虑分散控制策略,并在此基础上提出了一种以蓄电池为中心、带单向通信的分布式控制策略,在不同策略下对微网工作模式的切换方式进行了设计。最后,仿真与实验结果表明所提的微网工作模式及其切换方式能够正常工作,所提出的分布式控制策略相比于分散控制策略改善了控制性能,保证了经济性,满足系统可靠性要求。

To enhance the use of renewable energy sources such as solar energy,and solve the problem of stable power supply in remote areas or small systems,the need for a stable operation control strategy for independent DC microgrid with PV and a storage system has attracted attention.For underlying control in such a DC microgrid,a unified control method of MPPT and CV mode of PV is proposed.To ensure the stable operation of the microgrid with PV under different illumination and energy storage power conditions,the system working modes of DC microgrid are divided into three according to the different underlying control modes of PV and battery.As for the control mode of the microgrid,a decentralized control strategy is developed,and a distributed control strategy with battery as the center and one-way communication is proposed.The switching method is designed in both control strategies.Finally,simulation and experimental results show that the microgrid working modes and their switching methods proposed can work normally.Compared with the decentralized control strategy,the proposed distributed control strategy improves control performance,ensures economy,and satisfies the reliability requirements of the system.