Research on High Frequency Coupling AC-AC Transformer

South Asian memory ddr2 NT5TU64M16DG-AC

Probe domestic high frequency needle JKT-50L high frequency needle with 3 probes

Photocoupler

This paper proposes three AC-AC transformer structures. A DC transformer can convert a DC voltage to another one or more DC voltages proportional to it. The low frequency AC voltage can be considered as a slowly varying DC voltage relative to the high frequency chopping frequency in the DC transformer circuit. Therefore, combined with the concept of DC transformer voltage conversion, the series and parallel structure of the DC transformer can be used to realize the proportional conversion of AC energy. In this paper, the circuit structure and control scheme of AC-AC transform are studied, and simulation and experimental verification are carried out. The AC-AC transformer solution has the advantages of proportional conversion of low-frequency voltages of various shapes, realization of ZVS switching of all power switches, high conversion efficiency and power density, wide frequency band, and suitability for various load characteristics.

The DC-DC Converter has two basic types of output regulated DC-DC converter and direct current transformer (DCT) with unregulated output voltage. The DCT uses a high frequency chopper-transformer isolation-high frequency rectification to convert a DC voltage to another DC voltage or multiple that is proportional to it, and can be used for power transmission and voltage detection. The DC transformer has the advantages of proportional input and output voltage, frequency bandwidth, easy implementation of ZVS switch, and high power density.

In recent years, there have been many researches on isolated AC-AC direct conversion. The shortcoming of AC-AC direct conversion scheme is that there is a large voltage spike when the switch tube is commutated. This voltage spike is the inherent isolated Boost transform in the energy feedback process. Caused by the device, it is more difficult to suppress [11]. Based on the DCT concept, this paper proposes an AC-AC transformer (ACT) scheme. This conversion scheme does not perform voltage regulation, the duty cycle is D≈1, and there is no need for a filter inductor/boost inductor, so there is no inherent voltage spike problem.

The low frequency AC voltage can be considered as a slowly varying DC voltage relative to the high frequency chopping frequency in the DCT circuit. Therefore, the concept of DCT can realize the conversion of a low frequency AC to another frequency of the same frequency to realize the function of the AC transformer. In this paper, three kinds of ACT structures synthesized by series and parallel connection of DCT are proposed: 1 primary side parallel secondary side series; 2 primary side series secondary side series; 3 adopts bidirectional controllable switch. The control scheme was studied and simulated and tested.

ACT circuit composed of series connected in parallel with primary side

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