Improving DC-Bus Voltage Stability in CPLs: Feeding DC-DC Boost Converters Using a Hybrid Control Approach

In DC distribution networks (DCDNs), a constant power load (CPL) is connected to the DC bus, causing system instability due to its adverse impedance characteristics. To ensure system stability, a hybrid controller is proposed that combines a backstepping approach with a global integral terminal sliding mode controller (BGIT-SMC). This control scheme also addresses the non-minimum phase issue in DC-DC boost converters (DDBCs). Using Lyapunov stability theory, the BGIT-SMC controller ensures the overall system's stability. Simulation studies are conducted in MATLAB/Simulink under various conditions involving large disturbances. The results show that the BGIT-SMC controller significantly improves the stability of DCDNs in all aspects compared to the existing SMC (ESMC).