Terminal sliding mode with real and imaginary switching hyperplane controlled single-phase UPS systems

This paper presents a terminal sliding mode with real and imaginary switching hyperplane scheme for single-phase UPS systems. Compared to classic sliding mode control (SMC), terminal sliding mode control (TSMC) not only offers robustness to system uncertainties but also guarantees finite system state convergence time. However, in sliding motion, the system dynamics becomes a reduced-order dimension, thus losing the partial system dynamics, and resulting in system performance deterioration. For recovering incomplete system response, a real and imaginary switching hyperplane is designed to compensate the closed-loop system dynamics. With the proposed scheme, the output voltage of the UPS system yields the features of low distortion, and is insensitive to internal parameter variations and external disturbances. Experimental results are given to conform that the proposed scheme can achieve good system performance.