Non-isolated bidirectional high-gain dc/dc converter and frequency conversion control method

Abstract

The invention discloses a non-isolation bidirectional high-gain DC / DC converter and a frequency conversion control method, and belongs to non-isolation high-frequency power conversion in power electronic field. The non-isolation bidirectional high-gain DC / DC converter disclosed by the invention comprises a main circuit and a control circuit, wherein the main circuit mainly consists of a low-voltage end V<L>, a high-voltage end V<H>, two inductors (L<1>, L<2>), n+2 MOS transistors (S<1>, S<2>, Q<1>-Q<n>) and n capacitors (C<1>-C<n>), wherein n is cascading quantity. The invention also discloses the frequency conversion control method for the non-isolation bidirectional high-gain DC / DC converter. The switching frequency of the MOS transistors is regulated by the frequency conversion control method, so that current pulsation and ring current loss are reduced of each MOS transistor in the main circuit of the converter under the premise that realization of soft switching is ensured. The non-isolation bidirectional high-gain DC / DC converter and the frequency conversion control method can be widely applicable to storage battery energy storage or a new energy automobile motor driving system.

Description

technical field [0001] The invention relates to a non-isolated bidirectional power flow high-gain DC / DC converter and a frequency conversion control method thereof, belonging to the non-isolated high-frequency power conversion direction in the field of power electronics. Background technique [0002] Batteries are now widely used in various industrial and electronic products, such as uninterruptible power supplies (UPS), energy storage systems for AC and DC microgrids, and hybrid or electric vehicles. For higher power applications, the required DC voltage is generally higher, but the battery cell voltage is lower. In order to obtain high voltage, a large number of batteries need to be connected in series. However, it is difficult to ensure that the voltage of each battery is balanced. Some batteries may be overcharged or overdischarged after working for a long time. In severe cases, there may even be dangers such as fire and explosion. Therefore, it is generally necessary t...

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Problems solved by technology

[0008] Aiming at the technical problems that the traditional non-isolated bidirectional Buck / Boost converter has a limited voltage conversion ratio between the low-voltage side and the high-voltage side and cannot realize soft switching, the present invention discloses a non-isolated bidirectional high-gain DC / DC converter, and also discloses a method for The frequency conversion control method of the non-isolated bidirectional high-gain DC / DC converter, the technical problem to be solved is to realize the soft switching control of the non-isolated bidirectional high-gain DC / DC converter, reduce the current ripple and circulation loss under light load, Improve conversion efficiency

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