Bidirectional DC/DC converter capable of freely reversing, and control method thereof

Abstract

The invention discloses a bidirectional DC / DC converter capable of freely reversing, and a control method thereof. The bidirectional DC / DC converter comprises a high-voltage filtering unit, a full-bridge push-pull high-frequency isolation transformation unit, a filtering energy storage unit, a low-voltage filtering unit and a digital control system, wherein the high-voltage filtering unit stabilizes a high-voltage DC voltage; the full-bridge push-pull high-frequency isolation transformation unit realizes high-frequency isolation bidirectional power transmission of the converter; the filtering energy storage unit reduces low-voltage output current ripples when the converter is in positive step-down operation, and serves as a step-up inductor for energy storage when the converter is in negative step-up operation; the low-voltage filtering unit filters out a high-frequency ripple current so as to reduce the low-voltage side voltage ripples; and the digital control system realizes bidirectional power transmission and free reversing operation functions of the converter. The control method comprises the steps of sampling, conditioning and filtering, analog-to-digital conversion, digital filtering, voltage control signal updating, current control signal updating, digital PWM modulation, and PWM signal power amplification. The bidirectional DC / DC converter is capable of freely reversing in two directions, and the control method is simple and reliable.

Description

technical field [0001] The invention belongs to the technical field of power electronics application, in particular to a freely commutable bidirectional DC / DC converter and a control method thereof. Background technique [0002] Bidirectional DC / DC conversion technology refers to the application of power semiconductor devices, in the case of maintaining the same polarity of the DC voltage at both ends of the converter, it can realize the DC-DC conversion technology that adjusts the bidirectional transmission of energy as needed. It is widely used in aerospace, electric vehicle energy system, DC microgrid system and other new energy technology fields. The bidirectional DC / DC converter has the hardware conditions to realize synchronous rectification, and also has the advantages of small size, high efficiency, and small number of total components. A full-bridge push-pull bidirectional DC / DC converter based on a full-bridge push-pull structure. The high-voltage side adopts a vo...

AI Technical Summary

Problems solved by technology

[0006] The technical problem solved by the present invention is to provide a freely reversible bidirectional DC / DC converter to solve the problem of reciprocating switching between the forward and reverse working directions of the traditional full-bridge push-pull bidirectional DC / DC converter, and the switching circuit and the control circuit are complicated. Complex, low-reliability problems

Images