Single-stage forward type high-frequency linked inverter

Abstract

The invention discloses a single-stage forward type high-frequency linked inverter belonging to the field of power electronic inverter and comprising a primary side circuit, a first high-frequency transformer, a second high-frequency transformer and a secondary side circuit, wherein the primary side circuit comprises a power supply, two voltage-dividing capacitors and four power switch pipes; the first high-frequency transformer and the second high-frequency transformer both comprise primary side windings and secondary side windings; and the secondary side circuit comprises three four-quadrant high-frequency power switch, a filter inductor, a filter capacitor and a load. The single-stage forward type high-frequency linked inverter is formed in such a way that two two-way power flow forward converter units are in series connected at input ends in a staggered way and in parallel connected at output ends in the staggered way, the two two-way power flow forward converter units work in the staggered way all the time, and diodes of switch pipe bodies realize the magnetic resetting of the high-frequency transformers. The invention has low voltage stress of primary and secondary side switch pipes, low capacity of the voltage-dividing capacitors and high transformation efficiency and reliability, is suitable for a medium voltage input occasion and a high voltage input occasion and especially has extensive application prospect in a new energy power generation field.

Description

technical field [0001] The invention relates to an inverter, in particular to a single-stage forward high-frequency link inverter, which belongs to the field of power electronic converters. Background technique [0002] The inverter is a power conversion device that uses power semiconductor devices to convert DC power into AC power for AC loads. The inverter with high-frequency electrical isolation between the output AC load and the input DC power supply is called a high-frequency link inverter. The high-frequency electrical isolation components mainly play the following roles in the inverter: (1) Realize the The electrical isolation between the inputs improves the safety, reliability and electromagnetic compatibility of the inverter operation; (2) The matching between the inverter output voltage and the input voltage is realized, that is, the input voltage is allowed to be in a wide range The quality of the output voltage is guaranteed when changing, and its application ra...

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Problems solved by technology

[0004] Chinese patent CN1758521A proposes a set of single-stage bidirectional step-down DC converter-type high-frequency link inverters, and Chinese patent CN101414791A proposes a set of differential step-down DC chopper-type high-frequency link inverters. The basic idea of ​​the high-frequency link inverter is composed of two identical high-frequency electrical isolation bidirectional power flow DC converters that output anti-phase low-frequency sinusoidal pulsating DC voltage to form an inverter. The two DC converters output sine waves respectively. The positive half-cycle waveform and the negative half-cycle waveform, so in any half cycle of the output sine wave, there is always a DC converter in an idle state, so the utilization of the device is not maximized

In the above two patents, the high-frequency link inverter composed of the forward converter is also mentioned. Due to the special problem of the magnetic reset of the forward converter transformer, the maximum duty cycle of the switching tube is limited, and the switching tube’s higher voltage stress

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