Hybrid Backstepping and Super-Twisting Sliding Mode Control for DC-DC Boost Converter Feeding Constant Power Load for DC Microgrid Applications

The research presents an innovative control method that adapts its nonlinear control approach to solve the instability problems that occur in DC-DC boost converters (DBCs) that deliver constant power loads (CPLs) to DC microgrids (DCMGs). The proposed method combines backstepping control (BSC) with a super-twisting sliding mode controller (STSMC), which uses a finite-time disturbance observer (FTDO) to create a single system that delivers better transient performance and stronger system resilience than traditional methods. The FTDO provides accurate and fast disturbance estimation, which enables finite-time compensation and results in approximately a 0.4 ms reduction of settling time. The STSMC reduces high-frequency chattering, which occurs in standard sliding mode control, through its design, while the improved sliding surface design enables faster system recovery and lower overshoot, which reaches approximately 0.5% during sudden load or parameter changes. The researchers used Lyapunov theory to create mathematical conditions which demonstrate sufficient stability for their system. The controller demonstrates its effectiveness through multiple simulation tests and real-world experiments which show that it maintains voltage stability while delivering fast dynamic response and stable operation during major disturbances.