A predictive current-mode control method for a gan-based active-clamp flyback converter

Abstract

The invention discloses a predictive current mode control method of a GaN-based active clamp flyback converter, which belongs to the technical field of power generation, power transformation or power distribution. The present invention deduces the relationship between the converter loss and the valley current under a certain working condition by means of theoretical calculation, obtains the valley current and the corresponding dead time that minimize the loss, and stores them in the LUT unit in the form of a five-element array Middle; the control method can determine the valley current and dead zone time of the next cycle through the LUT unit through the sampling signal, thereby controlling the conduction time of the auxiliary switch and the dead zone time from when the auxiliary switch is turned off to when the main switch is turned on, avoiding The freewheeling loss and the loss caused by the reverse charging of the parasitic capacitance of the main switch can enter the high-efficiency working state after a period of adjustment, reducing the loss and improving the efficiency; the GaN-based power tube makes the dynamic performance of the converter more efficient. Well, for higher operating frequency, lower parasitic parameters further reduce loss and improve efficiency.

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 predictive hysteresis current mode control method for a GaN-based active clamp flyback converter, 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 highe...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to address the shortcomings 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 directly obtained by looking up the working condition of the circuit after checking the table 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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