Inverter based on series voltage switching at input terminal and its short-circuit loss suppression method

Abstract

The invention discloses an inverter based on series voltage switching at the input end and a method for suppressing short-circuit loss thereof. The outer loop of the first-stage inverter voltage feedbacks the inverter output voltage and the double-closed-loop control of the inductor current signal, and obtains the pulse control signal of the switching device of the bridge arm of the rear-stage inverter, so as to realize the output short-circuit current limit of the inverter; and, the inductor The current signal is converted into a DC voltage signal through rectification and filtering, and compared with the comparison reference signal, and the output series module of the front-stage DC-DC converter is controlled according to the comparison result to adjust the DC voltage. The inverter includes: a front-stage direct-to-direct converter and a rear-stage inverter, a short-circuit state maintenance judging module, and an output series voltage switching module. The invention can more quickly reduce the voltage stress of the inverter at the moment of short circuit, and better suppress the loss of switching devices when the inverter is short circuited in the 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...

AI Technical Summary

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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