Supertwisting Sliding Mode Control of Multi-converter MVDC power systems under constant power loads

A medium voltage dc integrated power system utilizes a dc/dc converter to supply constant power loads. In a poorly controlled system, the constant power loads can cause instability in the system due to its negatively incremental impedance. This paper presents a supertwisitng sliding mode control (STSMC) paradigm to control the medium voltage direct current (MVDC) power system operating under constant power loads. Extensive simulation carried out in Matlab/SIMULINK shows that, the proposed STSMC provides smooth and robust performance under varying constant power load (CPL) conditions. The STSMC is compared with previously proposed SMC and backstepping SMC techniques. The proposed techniques showed superior performance in terms of chattering and robustness under changing CPL conditions.