In DC microgrid (DC-MG), the loads connected with converters under strict control are\nconsidered as CPLs (constant power loads). When the voltage of CPLs decreases, the current\nincreases and the negative impedance characteristic of CPLs cause instability easily. Fortunately,\nappropriate Control for energy storage units could improve the system stability. However, most\ntraditional control methods for bidirectional DC-DC power converters (BDC) connected with\nbattery storage units do not quantitatively consider the stability influences of control parameters.\nThis paper quantitatively analyzes the stability influence of the BDC current-mode control\nparameters and the negative impact of CPLs and derives the control parameter determination\nmethod for BDC interfaced storage systems. Large signal stability constraints are obtained in terms\nof mixed potential function. According to the constraints, the large signal stability is improved when\nthe BDC control parameter kp increases, while the stability is degraded when the power of CPLs\nincreases. The control parameter determination method is very effective and convenient to apply,\nand the appropriate parameter kp for BDC is determined. The regions of asymptotic stability (RAS)\nidentify that the proposed control parameter determination method could improve the system\nstability effectively. The determination method is fully verified by the simulation and experimental\nresults.
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