Adaptive sliding mode control of buck converter feeding resistive and constant power load in DC microgrid

Abstract

Power converters are essential parts of microgrids (MGs), but they cause several problems. One of the most serious concerns with a DC microgrid (DCMG) is the constant power load (CPL), which has an incremental negative impedance (INI). INI has a negative dampening effect on the power efficiency of a power system. Sliding-mode control (SMC) has a hard attitude against external disturbances when compared to traditional control approaches like lead–lag, linear quadratic regulator, and PID. This paper suggests an adaptive sliding-mode control (ASMC) for a buck converter to supply a resistive and a CPL in a DCMG. The proposed controller provides large-signal stability during steady-state operation and maintains output voltage when the source voltage or CPL is changed. Moreover, the suggested controller significantly reduced the chattering effect, which is a major drawback of conventional SMC. An application of DCMG is presented to reveal the efficiency of the suggested ASMC method under both source voltage variation and constant power load variation.