Linear alternating current-direct current (AC-DC) converter for alternating chopped wave

Abstract

The invention relates to a linear alternating current-direct current (AC-DC) converter for an alternating chopped wave, a high-frequency conversion circuit and an impedance conversion circuit in the technical field of electrical and electronic engineering. An output end of the high-frequency conversion circuit is connected with an input end of the impedance conversion circuit. The high-frequency conversion circuit comprises a first filter circuit, an alternating chopping circuit, a high-frequency transformer and a second filter circuit, which are in cascade connection sequentially. The impedance conversion circuit comprises a rectifying bridge and a boosting circuit which is in cascade connection with the rectifying bridge; the midpoints of two bridge arms of the rectifying bridge are respectively connected with two alternating current output ends of the high-frequency conversion circuit; and an output end of the boosting circuit outputs a direct-current voltage. The linear alternating current-direct current (AC-DC) converter outputs a stable direct-current voltage and generates a unit input power factor at the same time, achieves a flexible voltage-regulating capability, obtains a linear input impedance, overcomes the defect that a power supply fluctuation and a load fluctuation interfere with each other, has the characteristics of novel design, strong generality and the like and has the advantages of simple structure and low cost.

Description

technical field [0001] The invention relates to an AC-DC converter in the technical field of power electronics, in particular to an AC-chopping linear AC-DC converter used for AC conversion. Background technique [0002] In the field of power electronics technology, in order to reduce the size of power frequency transformers for applications where high voltage AC voltage input-low voltage AC or low voltage DC voltage output, people have turned their attention to power electronic transformers, trying to reduce transformer size and improve conversion efficiency. and saving materials. In order to complete the high-voltage AC voltage input-low-voltage AC output, an AC-AC converter can be used, or an AC-DC-AC two-stage converter structure can be used, and the AC-DC converter part can be independently produced as a product with a lower DC output. Voltage, the latter stage can be reconfigured with a conventional DC-AC converter, and finally output a low-voltage AC voltage. Using ...

AI Technical Summary

Problems solved by technology

The direct AC-AC converter with single-phase input has a simple circuit, easy control, and low cost, but its function is limited, its voltage regulation and frequency conversion capabilities are poor, its low-voltage ride-through ability is poor, and its input power factor is low.

The three-phase input direct AC-AC converter has complete functions and high performance, but its circuit is complicated, the control is cumbersome, the cost is high, and the low-voltage ride-through ability is poor.

[0004] After searching the existing AC-AC converter technology suitable for high-voltage AC voltage input-low-voltage AC or low-voltage DC voltage output applications, it was found that "Research on Contactless Power Supply System Based on Single-phase Matrix Converter" (Power Electronics Technology, 2009, p. 11 Issue 43) and "Design and Realization of Voltage Regulator Based on Matrix Converter Topology" (Journal of Shanghai Normal University, 2009 Issue 1 Volume 38) The function of the single-phase-single-phase AC-AC converter And the performance is poor, the frequency conversion and voltage regulation ability of the output voltage and the input impedance are nonlinear, it is difficult to extend to the three-phase-single-phase converter; Chinese patent number: 02139030.4, patent name: power electronic transformer, the description of the power electronic transformer The topology and working principle are extremely complex, and the application is very difficult

[0005] In summary, direct AC-AC converters have the disadvantages of complex control and low input power factor, and indirect AC-AC converters require input power factor correction to reduce grid-side harmonic interference, which cannot be applied to high-voltage AC input-voltage Applications with AC or low voltage DC output

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