Inverter based on input end series voltage switching and short-circuit loss suppression method thereof

Abstract

The invention discloses an inverter based on input end series voltage switching and a short-circuit loss suppression method thereof, the method comprises the following steps: taking output DC voltageof a preceding stage DC-DC converter as input DC voltage of a post stage inverter; performing double closed-loop control through a post stage inverter outer voltage loop feed-back inverter output voltage and an inductive current signal, obtaining a pulse control signal of a bridge arm switch device of the post stage inverter, thereby realizing inverter output short circuit current limitation; moreover, converting the inductive current signal into a DC voltage signal through rectifying and filtering, comparing the DC voltage signal with a comparison reference signal, controlling an output series module of the preceding stage DC-DC converter according to the comparison result, and adjusting the DC voltage. The inverter comprises the preceding stage converter and the post stage inverter, a short-circuit state keeping judgement module and an output series voltage switching module. with the inverter and the method provided by the invention, reduction of voltage stress of the inverter can berealized more quickly at the moment when short circuit happens, and loss of the switch device caused when the inverter is in short circuit state can be suppressed better during a dynamic process.

Description

technical field [0001] The invention relates to an inverter based on series voltage switching at an input terminal and a short-circuit loss suppression method thereof, and belongs to the technical field of electric energy conversion devices. Background technique [0002] At present, in distributed power systems such as power systems in new energy, aircraft and electric vehicles, single-phase or three-phase inverters using SPWM modulation have high energy conversion efficiency, low harmonic content of AC power provided, and flexible control. and other advantages have been widely used. In order to improve the EMI and EMC electrical performance of the whole machine, it is necessary to adopt an electrical topology structure in which the input end is isolated from the output end of the inverter in most applications. In order to reduce the volume and weight of the whole machine, this isolation function is mostly realized by high-frequency magnetic isolation. , so it is often nece...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, provide an inverter based on the series voltage switching of the input terminal and its short-circuit loss suppression method, and solve the problem that the existing inverter is in the high-frequency switching state of SPWM modulation It leads to high loss of switching devices, resulting in short-circuit time and low reliability of the inverter system in short-circuit state

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