Off-grid three-level inverter anti-interference backstepping control method based on ESO

The invention discloses an anti-interference backstepping control method for an off-grid three-level inverter based on ESO. The method comprises the following steps: firstly, establishing a second-order mathematical model of an off-grid T-type three-level circuit with an LC filter, and changing the second-order mathematical model to a rotating coordinate system through coordinates; secondly, for a system under a rotating coordinate system, introducing two kinds of interference, namely parameter perturbation and load interference, and designing an extended state observer to estimate interference in the system; thirdly, combining the backstepping controller with the extended state observer, and designing a feedforward-feedback composite anti-interference voltage tracking controller; and finally, by selecting a proper observer and feedback controller gain, the off-grid T-type three-level inverter can accurately output an expected voltage value. Meanwhile, by means of an SVPWM modulation algorithm ...