A generalized model-based controller for the n-level CHB multilevel converter used as a shunt active filter

This paper presents the modeling and control design of a single-phase cascaded H-bridge multilevel converter used as a shunt active filter in the general case of n-levels. Based on a general model, a controller is proposed to compensate harmonic distortion and reactive power caused by nonlinear loads. For this, the controller must guarantee tracking of the line current towards an appropriately defined reference. In the proposed approach, the current reference has been selected to be proportional to the line voltage. The proposed controller also includes voltage loops to guarantee regulation and balance of the involved capacitor voltages. Simulation results are presented to assess the performance of the proposed controller.