A soft-switching bidirectional dc/dc conversion circuit and converter

Abstract

A soft-switching bidirectional DC / DC conversion circuit and converter, including k parallel-connected buck-boost circuits, the two bridge arm switches in each buck-boost circuit are switched in turn to enter the conduction state, and during the switching process there is In the dead zone, the driving waveforms of k buck-boost circuits are interleaved in time by 1 / (k f s ), f s Represents the switching frequency of the buck-boost circuit, where the switching frequency f s According to real-time changes in real-time input voltage, real-time output voltage and real-time output power, the f s Make the circuit work in intermittent working mode, and the energy stored in the energy storage inductor can complete the charge and discharge of the parasitic capacitance in each bridge arm switch within the dead time, and maintain the diode during the freewheeling process in the dead time energy consumption. The invention has low conduction loss and switching loss, high efficiency, and can maintain high-efficiency operation in a wide range; material cost is reduced; current ripple is superimposed, and the ripple frequency is doubled while the peak and valley cancel each other, effectively reducing the high-voltage and low-voltage sides Filter volume; unitized design for easy expansion.

Description

technical field [0001] The invention relates to the field of converters, in particular to a soft-switching bidirectional DC / DC converter. Background technique [0002] As the energy transmission link between high-voltage DC unit (DC busbar or high-voltage battery, etc.) , data centers, electric vehicles, aerospace, uninterruptible power supplies, etc. Generally, the current stress on the low-voltage side of the DC / DC converter is relatively large, and the voltage stress on the high-voltage side is relatively high. The Buck / Boost circuit in the traditional hard switching mode has serious switching loss (large current and high voltage during the switching process), reverse recovery is also very serious, and it is difficult to improve efficiency and frequency; at the same time, the size of the radiator and passive components often Larger, low power density; in addition, the voltage conversion rate and current change rate are large during the hard switching process, and the EM...

AI Technical Summary

Problems solved by technology

Using a resonant network (such as LLC, LCC, CLLC, LCL) to achieve soft switching can achieve high efficiency in a certain operating range or frequency range, but the effect is not ideal for wide-range applications

However, using an active clamp circuit or using an auxiliary circuit requires additional devices. On the one hand, the circuit is complex and the conduction loss increases; on the other hand, most converters can only transmit energy in one direction. does not apply when

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