Generic modularized analytical modelling of multiport LCL dc hub and multiport dc-dc

A common modularized analytical modelling method is proposed to obtain the linearized state-space model of two different multiport DC hubs (the multiport LCL dc hub and multiport back-to-back dc-dc converting system). Linearization of the electrical circuit and modularized form of the controllers are firstly presented. The sub-systems in modularized linear forms are then linked to form an overall linearized system. Correctness of the linearized model is firstly compared with the linearized model obtained using linmod in Matlab/Simulink. Time domain simulations are then used to compare the linearized model with the nonlinear model in Matlab/Simulink and detailed switching model in PSCAD/EMTDC, for a 4-port test system. Results show that the proposed modularized analytical modelling method is able to obtain highly accurate linearized model and in the meantime significantly reduce the complexity of calculation.