Abstract：To ensure the stable operation of the system, the academic community has conducted a large amount of research on small signal modeling and stability analysis of DC microgrids. However, the conclusions of small signal analysis are only valid within a local range, and the size of this range is uncertain. Therefore, methods based on small signal analysis are difficult to solve the problem of large disturbance instability in DC microgrids. When the system switches from the initial steady-state point to the target steady-state point, oscillation instability often occurs when the load changes significantly. To this end, a stable control method considering the control parameters of analogous virtual synchronous generator (AVSG) and flexible load regulation is proposed. Firstly, establish a Takagi Sugeno (TS) fuzzy model for the DC microgrid. Then, the Lyapunov function is constructed with the help of linear matrix inequality (LMI) tool to estimate the domain of attraction of the target steady-state point. If the largest estimated domain of attraction (LEDA) of the target steady-state point includes the initial steady-state point, then the system is asymptotically stable, otherwise there is a risk of instability. At this point, utilizing the flexible and adjustable virtual damping, virtual inertia, and flexible load resources within the DC microgrid, the LEDA of the target steady-state point can directly or indirectly include the initial steady-state point, thereby eliminating the risk of oscillation instability. To verify the effectiveness of the proposed method, hardware in the loop (HIL) simulation experiments have been built.The test results of control parameters show that adjusting the size of kd and Cvir until LEDA includes the initial steady-state point can avoid the risk of system oscillation instability. In addition, the test results of the operating trajectory show that by adjusting the operating trajectory of the system's operating points through flexible loads, while meeting the final load demand, the domain of attraction of the latter steady-state point sequentially includes the previous steady-state point, which can ensure the stable operation of the system. Finally, the LEDA error test results show that the estimation of the attraction domain in this example has a certain degree of conservatism, and the proposed method is suitable for this scenario. Conclusions can be drawn that: (1) Improving control parameters such as virtual damping and virtual inertia, as well as operating point trajectories based on domain of attraction theory, so that the LEDA of the target steady-state point directly or indirectly includes the initial steady-state point, is a practical and effective method to ensure stable system operation. (2) Compared with the dichotomy method, the method of adjusting the load power to the LEDA boundary can reduce the number of intermediate operating points and thus shorten the entire switching process. (3) Estimating the domain of attraction based on the TS fuzzy model and visually displaying the stability analysis results in a graphical manner can be used to guide the parameter tuning of AVSG.
王慧, 赵书强, 陈旭博, 孟建辉, 田艳军, 高本锋. 含类虚拟同步发电机和柔性负荷的直流微电网大信号稳定控制方法[J]. 电工技术学报, 2025, 40(3): 705-716.
Wang Hui, Zhao Shuqiang, Chen Xubo, Meng Jianhui, Tian Yanjun, Gao Benfeng. Large Signal Stability Control Method of DC Microgrid with Analogous Virtual Synchronous Generator and Flexible Load. Transactions of China Electrotechnical Society, 2025, 40(3): 705-716.
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2025, Vol. 40 
