Resonant control for H-Bridge topologies based on single-phase Current-Source Inverters

This work deals with the control of a single-phase Current Source Inverter (CSI) in a three-phase array which can be used for both power drives and PV applications. Unlike in three-phase inverters, where the Fortescue Transform or Park Transformation can be applied in order to simplify the design of the controllers, for single-phase systems they cannot be directly applied making the control a difficult task if a rotating reference frame is chosen. On the other hand, Resonant Control (RC) is a control strategy that allows working with sinusoidal references and ensuring zero steady state error. This paper studies the resonant control of a single-phase CSI in a three-phase array, considering a design in continuous as well as discrete time domain. The resonant control is justified because the current sources should not be considered equals at all times, leading to independent control in each phase, or each cell, where the current source value and the load current can be feed-forward into the controller both of them disturbances, making the load voltage control in each cell easier to accomplish. To corroborate the mathematical analysis, the proposed control scheme is tested under different conditions and disturbances, including a stability study.