Sliding Mode Control Based Direct Power Control and Equivalent Space Vector Modulation of Three-Switched Two-Level Rectifier

Abstract

In order to eliminate the defect of conventional PI controller which is too sensitive to the variation of system parameters, a direct power control (DPC) strategy based on sliding mode variable structure was presented, the DPC mathematics model of three-switch two-level rectifier was developed in detail, and the proposed control system diagram was derivated in deta il and the realized method was shown in this paper. In addition, aiming at the complex space vector pulse width modulation (SVPWM), a simplified equivalent SVPWM based on the carried-based pulse width modulation was proposed for this topology. The paper combined DPC scheme based on sliding mode control (SMC) and equivalent SVPWM technique together to achieve a constant switching frequency and the midpoint potential balance, while the rectifier works with unity power factor and reduces the switching losses. Finally, the MATLAB/Simulink model based on three-switch two-level rectifier was built, the results illustrated that the combined strategy was easy to design and implement with possessing good robustness and dynamic performance.