基于储能装置的自主直流电网系统分散控制与非线性稳定性分析

Decentralized Control and Nonlinear Stability Analysis of Autonomous DC Grid Systems with Energy Storage Devices

摘要:

直流配电系统和直流微电网因与大多数分布式能源、储能设备及负载的直流特性高度兼容，成为新兴的替代能源解决方案。为应对传统直流系统中功率平衡和稳定性问题，提出了一种基于储能装置的自主直流电网系统的分散控制策略及其非线性稳定性分析方法。首先，构建了一个包含多种直流分布式能源、并联电池支路和可变直流负载的非线性直流电网模型，探讨了在电子电源接口上应用简单分散式控制器的实现路径；其次，设计了完全独立于系统参数的级联控制器方案，并纳入系统模型进行全面的非线性稳定性分析；然后，通过应用先进的李雅普诺夫方法，对整个非线性系统进行严格的稳定性和收敛性分析，该方法无需依赖具体系统特性，确保系统的稳定运行。最后，通过案例仿真验证，证明了所提方案在实现系统稳定性和功率平衡方面的有效性。

Abstract:

DC distribution systems and DC microgrids are gaining increasing attention as emerging alternative energy solutions due to their compatibility with DC characteristics of most distributed energy resources, storage devices and loads. To address the challenges of power balance and stability in traditional DC systems, a decentralized control strategy and nonlinear stability analysis method for autonomous DC grid systems with energy storage devices is proposed. Firstly, a nonlinear DC grid model is constructed, including various DC distributed energy resources, parallel battery branches and variable DC loads, which explores the implementation path of simple decentralized controllers on electronic power interfaces. Secondly, a cascaded controller scheme is designed, which is completely independent from system parameters and incorporated into system model for comprehensive nonlinear stability analysis. And then, by applying advanced Lyapunov method, a rigorous analysis of stability and convergence of the entire nonlinear system is conducted without relying on specific system characteristics, which ensures the stable operation of system. Finally, through the detailed simulations, the effectiveness of the proposed scheme in achieving system stability and power balance is demonstrated.