Universal DC off-grid hydrogen production system nonlinear energy hub model

The invention discloses a non-linear energy hub model of a universal direct-current off-grid hydrogen production system. The non-linear energy hub model comprises the following steps: (1) establishing non-linear dynamic models of a DAB, an inverter, a rectifier, an electrolytic cell, a fuel cell and an energy storage unit; (2) establishing a modular conversion characteristic matrix of each subsystem; (3) establishing a node-branch incidence matrix based on the direct current off-grid hydrogen production system; (4) establishing an input port-branch incidence matrix, an output port-branch incidence matrix and an internal node-branch incidence matrix; and (5) establishing a nonlinear energy hub model of the direct-current off-grid hydrogen production system. According to the method, a modular nonlinear conversion characteristic matrix established according to the working mechanism of each subsystem in the direct current off-grid hydrogen production system is combined with a node-branch incidence matrix establis