A New Adaptive Damping Control for Load-side Converters to Mitigate Instability in DC Microgrids for Constant Power Loads

The stability issue caused by constant power loads (CPLs) is becoming more prevalent in the case of DC microgrids (DC MGs). Active damping (AD) control methods are the best way to solve such problems. Either source side and load side AD methods exist in this research area. Source side active damping control methods outperform when the source converter has an input LC filter. Hence active damping control methods for load-side converter control are needed to solve the problem of CPL negative incremental resistance (NIR). Due to load and parametric variations, existing AD control methods should have adaptive features. Existing methods have very complex adaptive control approaches. Therefore, this study incorporates a novel feed-forward mechanism applied to the Point of Load (POL) converter's input port to solve the DC MGs instability problem. The stability criterion should be satisfied throughout the operating range to ensure stability. Hence, the proposed technique would effectively change the input admittance by introducing an adaptive feed-forward compensation term in the secondary control loop. The adaptive damping solution-based approach demonstrates extensive operating ranges with minimum ripple and noise in input voltage due to immediate control input variation. The research goes into great depth on cancelling negative impedance. The idea lowers DCMG oscillations without increasing the system's complexity or dissipative properties. The proposed control's effectiveness and findings verify in MATLAB/SIMULINK environment. Concerning the benchmark technique, the proposed approach reduces the ripple in DC bus voltage from 1.7% to 0.7%.