Modeling and Oscillatory Stability Analysis of DC Microgrid with Pulse Load

More and more applications of pulse load (PL) in island DC microgrid, the instability issues caused by PL has been paid more attention. Under pulsed load operation, the system exhibits a periodic steady-state characteristic, which can cause unacceptable voltage oscillations in the system. In order to make the system with PL operate stably, it is necessary to carry out the oscillatory stability analysis of DC microgrid with PL. However, the nonlinear period and time-varying characteristics of PL make the system modeling and stability difficult. To address these problems, a harmonic state space (HSS)-based impedance analysis of DC microgrid with PL is further developed in this paper. The modeling method takes into account the nonlinear periodic time-varying characteristics of the PL, which makes it possible to analyze the small-signal stability of a power system with PL. In addition, the HSS-based impedance analysis is further developed to assess the system stability and voltage oscillation. Finally, the accuracy and validity of the proposed method is verified by case study.