Energies, Vol. 19, Pages 781: Finite-Time Backstepping Control for Stand-Alone Three-Phase Voltage-Source Inverters Based on Disturbance Observer

Energies, Vol. 19, Pages 781: Finite-Time Backstepping Control for Stand-Alone Three-Phase Voltage-Source Inverters Based on Disturbance Observer

Energies doi: 10.3390/en19030781

Authors:
Shiwei Wu
Dejun Pan
Guanguan Zhang
Le Chang
Xiaoling Wang
Cheng Fu

For the three-phase voltage-source inverters (VSIs), load disturbances and parameter uncertainties degrade the quality of output voltages, potentially leading to system instability. To improve steady-state precision and disturbance rejection, this paper suggests a finite-time backstepping control (FTBC) strategy that incorporates a fixed-time sliding mode disturbance observer (FTSMDO). Firstly, this paper establishes a new dynamic model of the three-phase VSI considering load disturbances, parameter uncertainty and cross-coupling effect. Subsequently, a fixed-time disturbance observer is then developed to precisely estimate the uncertain disturbances, with its convergence time not reliant on the system’s initial conditions. Concurrently, a finite-time differentiator is developed to achieve the desired signals, thereby sidestepping the “explosion of complexity” problem. A finite-time controller is constructed to obtain stable three-phase output voltages. Theoretical and test analysis demonstrate the proposed method is effective. Compared with the PI control, the proposed strategy improves dynamic performance and enhances disturbance-rejection capability under time-varying load disturbances.