VDCM-based distributed secondary regulation research strategy for DC microgrids

Compared to AC microgrids, DC microgrids do not need to consider frequency, phase, reactive power, etc., but the fluctuation of loads will adversely affect the DC bus voltage. Nonetheless, the conventional MPC (Model Predictive Control) control approaches have been found inadequate in directly modulating the voltage, underscoring the imperative for an innovative control paradigm. To address this, the present study introduces a novel, distributed secondary regulation control strategy grounded in VDCM, meticulously designed to preserve the stability of the DC bus voltage by dynamically responding to load fluctuations and system disturbances. In this paper, the virtual DC generator is used as the underlying control strategy, so that the converter in the microgrid can simulate the dynamic characteristics of the DC generator, which can reduce the impact of power fluctuations on the bus voltage. On this basis, a distributed communication network, combined with a dynamic consistency algorithm, is used to propose a distributed secondary voltage regulation method based on VDCM, which further maintains the stability of the DC bus voltage under disturbances. Conclusively, a robust simulation platform, developed within the MATLAB/Simulink environment, demonstrates that the proposed strategy adeptly sustains the average system voltage stability, even amidst fluctuating conditions, thereby validating its efficacy and robustness.