Current Sensorless Sliding-Mode Voltage Control for <i>LC</i> Filtered Three-Level T-Type Inverters
Cheng Fu, Chenghui Zhang, Guanguan Zhang, Zicheng Zhang
Abstract
This brief focuses on the current sensorless output voltage control of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$LC$ </tex-math></inline-formula> filtered three-level T-type inverter (3LT2I). First, the 3LT2I dynamic models with lumped disturbances (integrating load disturbances, parameter uncertainties, and unmeasured inductor currents) are established. Then, finite-time observers are designed to estimate the lumped disturbances, providing the active anti-disturbance ability and eliminating current sensors. Based on this, continuous sliding-mode controllers are designed in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$dq$ </tex-math></inline-formula> -axis to achieve fast and accurate output voltage tracking. Test results demonstrate the effectiveness of the proposed strategy, which outperforms the adaptive method in terms of dynamic response and control accuracy when facing load disturbances and nonlinear loads.