Current-type rectifier control N+1 backup high-frequency switching power supply

Abstract

The invention discloses a current-type rectifier control N+1 backup high-frequency switching power supply. The main circuit of the switching power supply comprises a power module parallel circuit in a redundant structure; the input end of the power module parallel circuit is connected with a three-phase power distribution circuit; the power module parallel circuit comprises N+1 power modules in parallel connection, and N is no smaller than 1; each power module has the same inner structure and an IGBT is adopted as a main power switching device; each power module has an independent circuit breaker for main circuit opening and closing control; the control circuit of the switching power supply generates current-type PWM driving pulses through a digital control technology, and on and off control on the IGBT can be realized. a voltage-type control mode is enhanced to the current-type control, the control precision is higher, the current equalization effects are better, and in a high-power N+1 backup scheme, balance control of each unit is more consistent, and simultaneous rise and simultaneous fall of current and voltage can be realized.

Description

technical field [0001] The invention relates to a switching power supply, in particular to a current-type rectification control N+1 backup high-frequency switching power supply. Background technique [0002] At present, the output waveforms of high-frequency switching power supplies include: continuous DC, DC half-sine wave, and pulse waveforms. The pulse waveform can also be subdivided into: forward pulse, reverse pulse, bidirectional pulse, and DC superimposed pulse wave form. Different output waveforms can be realized independently by different power supplies, and multiple output waveforms can also be integrated in one power supply. [0003] In the prior art, the thyristor power frequency phase-controlled rectification power supply scheme is as follows figure 1 As shown in .a and 1.b, using a single-phase bridge half-controlled rectifier circuit, two output waveform forms of DC sine half wave and continuous DC can be realized. In order to achieve step-down and electric...

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Problems solved by technology

[0004] (1) There are huge and heavy power frequency transformers. In order to avoid the three-phase unbalance problem of the power grid, the transformer needs to consider the design scheme of the balancing transformer (T-Scott);

[0005] (2) When the DC sine half wave is output, there is a DC component in the secondary side current of the power frequency transformer, which is likely to cause DC magnetization of the iron core, making the iron core work near magnetic saturation

In order to prevent the occurrence of magnetic saturation, the air gap needs to be increased in the iron core of the transformer, so that the reluctance of the iron core increases and the efficiency decreases;

[0006] (3) For continuous DC output, in order to meet the power supply ripple requirements, it is difficult to design power frequency filtering and higher frequency filtering circuits;

[0007] (4) Thyristor power frequency phase-controlled rectification scheme has the problems of low power factor, large harmonic current, slow dynamic adjustment speed and poor stability;

[0008] (5) This scheme cannot realize pulse waveform output, and the DC sine half-wave frequency is fixed (50Hz) and cannot be adjusted

[0009] (6) Due to the voltage-type pulse width modulation scheme, its control precision is low and the current sharing effect is general

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