Output current control method of isolated bidirectional DC/DC conversion circuit

Abstract

The invention discloses an output current control method of an isolated bidirectional DC / DC conversion circuit, which comprises the following steps of: performing error adjustment on the current of a low-voltage side output inductor according to a target current value and calculated ts value and k value, and reducing the error after multiple times of error adjustment until an error current output value is zero, at the moment, an actual time signal value modulates on and off of each switching tube through the PWM controller, so that a current value of an output inductor at a low-voltage side is equal to a required target current, loop control is carried out on the current to stabilize and adjust an actual current value of the output inductor, on-off states of each switching tube are controlled through the PWM controller, and the current value of the output inductor at the low-voltage side is equal to the required target current. By adopting the above circuit structure and cooperating with a body diode in the switch tube, bidirectional transmission of electric energy can be realized, high-efficiency operation is ensured, a modulation scheme is simplified, and reactive current of the transformer is small under a full-load condition, so that the operation efficiency is high, and the transformer can be applied to the fields of energy storage, electric automobiles, new energy and the like.

Description

technical field [0001] The invention relates to the technical field of DC converter output current control, in particular to an output current control method of an isolated bidirectional DC / DC conversion circuit. Background technique [0002] The energy storage device is connected to the DC bus through a bidirectional DC / DC converter to realize bidirectional flow between the energy storage device and the bus. The voltage fluctuation range of some energy storage devices is wide, but the voltage level is far lower than the voltage level of the DC bus. Therefore, it is necessary to provide a wide range of bidirectional DC / DC converters to boost the energy storage output voltage. For high-power isolated DC / DC converters, they can be divided into resonant type and non-resonant type. Among non-resonant isolated DC / DC converters, there are phase-shifted full-bridge, DAB (Dual-activeBridge) circuits, etc., but such circuit structures have certain limitations. For example, the trad...

AI Technical Summary

Problems solved by technology

In non-resonant isolated DC / DC converters, there are phase-shifted full-bridge, DAB (Dual-activeBridge) circuits, etc., but these circuit structures have certain limitations.

For example, the traditional phase-shifting full bridge can only transmit power in one direction, and the phase-shifting modulation method of the traditional DAB circuit structure is more complicated and less stable, thus affecting power conversion

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