Grading limiting circuit for aerospace alternative-current/direct-current (AC/DC) converter

Abstract

The invention relates to a grading limiting circuit for an aerospace alternative-current / direct-current (AC / DC) converter, which is characterized by comprising a power part and a control part, wherein the power part comprises an input filter unit, a power factor correction (PFC) conversion circuit unit, a high-frequency isolation DC / DC conversion circuit unit and an auxiliary power supply unit; and the control part comprises a PFC conversion controller unit, an input power supply voltage detection circuit unit, a DC / DC limiting point setting circuit unit and a DC / DC control unit. The input filter unit is arranged at a first stage, so the interference of the power supply can be reduced after the inputted AC power supply is filtered. The AC power supply after being filtered is converted by the PFC conversion circuit unit into 410V DC power supply to be outputted, waveform of the inputted current is maintained to be consistent with the waveform of the voltage of the power supply, so the input power factor is approximate to 1. The 410V DC voltage is converted to a power supply voltage (28V or 57V) required by a load through the high-frequency isolation DC / DC conversion circuit unit.

Description

technical field [0001] The invention relates to an AC / DC conversion device that can be used for two high-voltage AC inputs, in particular to a high-voltage AC / DC conversion device used in the aerospace field. Background technique [0002] AC / DC conversion devices have been widely used in the aerospace field. Commonly used power supplies for aerospace power supplies are AC 220V / 50Hz and 115V / 400Hz, which need to be converted into output voltages of DC 28V or DC 57V (power is 3KW), and there are two types of input power switching in actual use. The characteristic of this power supply is that the input and output are electrically isolated and the output DC voltage is much lower than the input AC voltage. The usual circuit design structures include: 1. Rectification and voltage stabilization after step-down by a power frequency / intermediate frequency transformer; 2. Rectification circuit and DC / DC high-frequency isolation voltage conversion circuit. The main disadvantages are:...

AI Technical Summary

Problems solved by technology

The main disadvantages are: in order to adapt to different input power supply voltages, scheme 1 needs to design a special circuit to match it, and control it through a switching circuit. The circuit is complicated, there are many varieties, large volume, high cost, and low reliability.

The output current is limited according to the output power of the input voltage of 115V / 400Hz. This strategy does not make full use of the output potential of the input voltage of 220V / 50Hz.

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