Parameter design method of phase-shifted full-bridge converter based on ZVS load range

Abstract

The invention relates to a parameter design method for a phase-shifted full-bridge converter based on a ZVS load range, and the method comprises the steps: calculating the turn ratio n of a primary side to a secondary side of a transformer according to the gains of an input voltage Vin and an output voltage Vo and the maximum allowable duty ratio loss Dloss _ max of a system; calculating the output filter inductance L0 according to a volt-second balance principle of the output filter inductance L0 and the current ripple coefficient alpha of an output inductor; constructing a function lambda1(Lr, Dloss _lambda) about the ZVS soft switching range lambda and the duty ratio loss Dloss_lambda under the lambdaIo load condition according to the volt-second balance principle of a resonant inductorLr; according to a hysteresis arm soft switching realization condition, taking energy stored by the resonant inductor Lr equals energy required for completing current conversion by a hysteresis arm parallel capacitor Clag as a critical condition, and constructing a function lambda 2 (Lr, Dloss _ lambda); and solving a set M (lambda, Lr, Dloss _ lambda) of all points satisfying the critical soft switching condition lambda 1 (Lr, Dloses _ lambda) = lambda 2 (Lr, Dloses _ lambda), and determining an optimal solution (lambda, Lr, Dloss _ lambda). According to the method, circuit parameters of thephase-shifted full-bridge ZVS converter can be screened and designed simply and visually.

Description

technical field [0001] The invention belongs to the technical field of ZVS converters, in particular to a parameter design method of a phase-shifted full-bridge converter based on a ZVS load range. Background technique [0002] The phase-shifted full-bridge ZVS converter can make full use of the parallel capacitance and resonant inductance of the power device to realize the zero-voltage conduction of the power switch, which not only reduces the conduction loss of the switch tube, but also increases the switching frequency of the power tube and reduces the The volume and weight of the system are reduced, and the conversion efficiency of the system is improved. Therefore, the phase-shifted full-bridge ZVS converter is widely used in DC-DC direct current power supply. [0003] Such as figure 1 Shown is the basic topology of the main circuit of the ZVS phase-shifted full-bridge DC-DC converter, where Q1 and Q3 are lead tubes, Q2 and Q4 are lagging tubes, D1~D4 are switch body ...

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Problems solved by technology

However, there is no systematic research and analysis on the complex parameter optimization design of phase-shifted full-bridge converters. For example, literature: Optimization and parameter design of phase-shifted full-bridge ZVS converters. Electronic Devices, 2016,39(3):650 -654, for the phase-shifted full-bridge ZVS converter, introduced its working principle and designed the parameters of the key components of the resonant main circuit in detail, but it did not quantitatively analyze the key parameters that affect the ZVS of the lagging arm, such as the resonant inductance and IGBT dead time

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