虚拟电厂运行策略及DG分布式控制研究

Research on Operation Strategy of Virtual Power Plant and Distributed Control of DG

【目的】虚拟电厂通常由分布式发电(distributed generator,DG)单元组成,当系统缺少电网支撑时,需要合理的综合运行策略和准确的控制方法保证虚拟电厂平稳运行。【方法】首先,针对虚拟电网发电问题提出了一种基于功率差余值的运行策略。然后,针对系统中DG的发电控制问题设计了一种有限时间分布式控制器。将电压和频率的幅值在有限时间内调整到标称值,并实现了有功功率在各DG单元间的分配。与传统的集中式控制策略不同,所建立的控制方法基于分布式结构,只需要相邻DG单元之间通过稀疏通信网络进行信息交换。【结果】通过仿真实验验证了该控制方法的可行性,以及对模型参数不确定性和负载变化的鲁棒性。【结论】与以往研究相比,所提出的运行策略对系统工况进行了更为详细地划分,有效提高了系统的稳定性和安全性。

[Objectives]Virtual power plant is usually composed of distributed generator(DG).When the system lacks power grid support,practical and reasonable comprehensive operation strategies and accurate control methods are needed to ensure the smooth operation of virtual power plant.[Methods]An operation strategy based on system fluctuation value was proposed.Then,aiming at the problem of generation control of distributed generators in the system,a distributed finite-time controller was designed.The amplitudes of voltage and frequency were adjusted to nominal values within a finite time,and the active power was distributed among each DG unit.Different from the traditional centralized control strategy,the proposed control method is based on distributed junction,which only requires information exchange between adjacent DG units through sparse communication network.[Results]The feasibility of the proposed control method and its robustness to the uncertainty of model parameters and load variation were verified by simulation experiments.[Conclusions]Compared with previous studies,the proposed operation strategy divides the system operating conditions in more detail,effectively improving the stability and security of the system.