Predictive current mode control method of GaN-based active clamp flyback converter

Abstract

The invention discloses a predictive current mode control method of a GaN-based active clamp flyback converter, and belongs to the technical field of power generation, power transformation or power distribution. According to the invention, the method comprises the steps: deriving a relational expression of converter loss and valley current under a certain working condition through a theoretical calculation method, and solving the valley current enabling the loss to be minimum and corresponding dead time, and storing the valley current and the corresponding dead time in an LUT unit in a quintuple array mode. According to the control method, the valley current and the dead zone time of the next period can be determined through the LUT unit according to the sampling signal, so the conductiontime of the auxiliary switch and the time from the turn-off of the auxiliary switch to the turn-on of the main switch are controlled, and the follow current loss and the loss generated by reverse charging of a parasitic capacitor of the main switch are avoided; an efficient working state can be entered after a period of adjustment, so that the loss is reduced, and the efficiency is improved; the GaN-based power tube enables the dynamic performance of the converter to be better, the converter is suitable for higher working frequency, the loss is further reduced due to lower parasitic parameters, and the efficiency is improved.

Description

technical field [0001] The invention discloses a predictive current mode control method for a GaN-based active clamp flyback converter, in particular to a GaN-based active clamp flyback converter predictive hysteresis current mode control method, which belongs to power generation and power transformation Or the technical field of power distribution. Background technique [0002] In today's power supply field, MOS tubes mostly use Si-based materials and GaN-based materials. GaN has the advantages of wide band gap, high critical breakdown electric field, high saturation electron drift velocity, and high electron mobility, which makes GaN-based materials MOS Compared with the MOS tube of Si-based material, the tube has the advantages of small on-resistance and fast switching speed, which greatly reduces the on-state loss and switching loss of the device, thereby improving the efficiency and operating frequency of the converter. In addition, GaN-based materials have higher with...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned background technology and provide a predictive current mode control method for a GaN-based active clamp flyback converter. The working condition can be obtained directly by looking up the table after detecting the working condition of the circuit The valley current and dead time corresponding to the lowest loss point can quickly reach the best working state, reduce loss, improve efficiency, and solve the problem that the existing active clamp flyback converter control strategy cannot compromise switching loss and conduction. The technical problem that the total loss must be minimized when the pass loss is exactly exactly ZVS

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