abstract
- © 2022 Elsevier LtdThis paper presents a control methodology for a three-phase cascaded H-bridge (3ph-CHB) converter in the general case of n-levels (3ph-CHB-nL). The proposed method is used to compensate reactive power and to eliminate the harmonic currents caused by non-linear loads. For this, a generalized modeling process of the CHB-nL converter is first introduced, which includes the effect of the line impedance. The control objectives comprise a current tracking loop, as well as regulation and balance voltage loops for all H-bridges. The proposed controller solution includes an internal control loop to ensure line current tracking towards an extended reference that includes additional degrees of freedom. The current reference has been designed in such a way that, in the steady state, it becomes proportional to the fundamental component of the line voltage. The proposed controller also includes outer voltage loops to guarantee regulation and balance of the involved capacitor voltages. Experimental results have been realized in a three-phase and five-level CHB (3ph-CHB-5L) prototype to assess the performance of the proposed generalized controller.