Leakage inductance current slope direct control method of isolation type two-way three-level converter

Abstract

The invention relates to a leakage inductance current slope direct control method based on an isolation type two-way three-level converter and belongs to the field of power electronics. Leakage inductance current is directly sampled at a high speed in real time to realize direct control on the leakage inductance current; even a transformer turn ratio error and circuit parasitic parameters exist, better control on leakage inductance current slope can also be realized; thus the current stress and current-circulation loss of a circuit are reduced. The low voltage side of a main circuit is formed by a current type half-bridge topology structure with an active clamping circuit; a high voltage side adopts a three-level half-bridge topology structure; a control strategy is that output voltage, input current and the leakage inductance current are sampled, operation is performed by a digital operation controller (DSP (digital signal processor)), a duty ratio and a phase shift angle are generated by a digital PI regulator, switching tubes of primary and secondary sides are controlled, the circuit power transmission direction and the leakage inductance current slope are directly controlled, and thus the less current stress and current-circulation loss and seamless switching of two-way operation of the circuit are realized.

Description

technical field [0001] The patent of the present invention provides a direct slope control method of leakage inductance current of an isolated bidirectional three-level converter, which belongs to the direction of high-frequency switching power supply in the field of power electronics. Background technique [0002] For isolated bidirectional three-level converters used in high-voltage applications, the low-voltage side adopts a current-mode half-bridge topology with an active clamp circuit, and the high-voltage side adopts a three-level topology. The current-mode half-bridge topology with an active clamp circuit on the low-voltage side can reduce the ripple of the input current very well and improve the service life of the battery. The high-voltage side adopts a three-level topology, so that the voltage stress of the power device on the high-voltage side is reduced to half of the voltage on the high-voltage side, so that MOSFETs with lower withstand voltage, smaller on-state...

AI Technical Summary

Problems solved by technology

However, when there is an error in the transformer turns ratio or there are parasitic parameters in the circuit, the slope of the leakage inductance current cannot be precisely controlled, so that the current stress and circulation loss of the switch tube cannot be kept in an optimal state