A discrete-time sliding mode controlled current-source inverter used in AC power source

This paper presents a full digital controlled current-source inverter (CSI) used in AC power source, which may generate sinusoidal currents with adjustable amplitudes and frequencies over a wide range, as well as various arbitrary waveforms that fundamental sine wave with harmonics. A discrete-time sliding mode controller based on a novel reaching condition has been applied to control the CSI. The design of the sliding surface coefficient is analyzed to ensure that the system will converge to zero asymptotically. A simple output current feedback design is used in this system, while a voltage predictor utilizes the output current to estimate the desired inductor voltage. Some experimental results are demonstrated to prove that the proposed control strategy provides excellent robustness with regard to external disturbances, and well steady state operation and dynamic response of the output current.