Preset time feedback controller, control system and control method of dual-active bridge circuit

The invention discloses a preset time feedback controller of a dual-active bridge circuit in the technical field of power electronics, and the controller comprises a time conversion law which is used for inputting preset time tp and outputting a scale transformation coefficient mu (t); the time scale transformation law is used for inputting a scale transformation coefficient mu (t) and a system error e (t) and outputting a scale error signal Z (t), and the system error e (t) is a difference value between a sampling signal x (t) of the output voltage and an expected voltage xd; the feedback control law is used for inputting a sampling signal x (t) of an output voltage, outputting a scale transformation coefficient mu (t), a change rate of a time scale transformation coefficient, an output scale error signal Z (t), a system error e (t), a change rate of an expected voltage and a non-negative parameter alpha, and outputting a control signal u (t) to control the dual-active bridge circuit through the PWM modulato