A Modular Modulation Decoupling Algorithm for Multiple Active Bridge Based Multiport EV Charger

To enhance the power density and increase the efficiency of electrical power distribution systems (EPDSs), the concept of multiple active bridge (MAB) converters has been developed. The conventional MAB control method utilizes proportional and integral (PI) voltage controllers for each dc port without decoupling, facing the drawbacks of slow dynamic responses and limited power transfer capability. This article proposes a Newton iteration-based decoupling algorithm combined with a current decoupling control algorithm to realize the voltage controls for the multiport electric vehicles (EV) charger applications. This control strategy composes of the dc reference current generators and the current to phase shifts decoupling algorithm, which divides the MAB converter with n ports, into n-1 virtual dual active bridge (DAB) subbranches. Generalized phase shift(GPS) modulation was utilized in the decoupling algorithm to quantitatively characterize the relationship between the phase shift and the port average current, aiming at achieving the 'modular' switching of the fundamental modulations. The complexity and accuracy of the proposed online offline Newton decoupling (O2ND) algorithm have been evaluated and compared with Newton decoupling (ND) algorithm and simplified Newton decoupling algorithm (SND). The effectiveness and flexibility of the O2ND algorithm and the performance of the O2ND current decoupling control are verified through a comparative assessment by means of simulation and experimental results.