The invention discloses a three-level T-type
inverter grid-connected control method based on a sliding-mode observer, and relates to the technical field of grid-connected control. According to the three-level T-type
inverter grid-connected control method based on the sliding-mode observer, a preset time sliding-
mode control scheme based on the sliding-mode observer is provided, a continuous
Sigmoid function is introduced to replace a nonlinear
sign function to construct a sliding-mode observation reaching law, signals can be effectively and smoothly controlled, and the control precision of the three-level T-type
inverter grid-connected control method based on the sliding-mode observer is improved. The inherent high-frequency buffeting phenomenon of traditional
sliding mode control due to a
sign function is remarkably suppressed, and meanwhile, the convergence speed and tracking precision of the
system are improved. On the basis of observing
power grid voltage serving as external disturbance through a sliding-mode observer, feedforward compensation is performed on the external disturbance, and the feedforward compensation is applied to a sliding-
mode control reaching law of preset time so as to suppress buffeting and accelerate the convergence process of output current. And the timeliness and the stability of grid-connected control of the three-level T-type inverter based on the sliding-mode observer are improved.