High-voltage gain DC-DC direct-current converter

Abstract

The invention discloses a high-voltage gain DC-DC direct-current converter which comprises a direct-current power supply, a power switch tube, a three-winding coupling inductor, a capacitor and an output circuit. On or off of the power switch tube is controlled to control switching of working states of the circuit, so that whether the direct-current power supply provides energy required by circuit working for the coupling inductor and the coupling capacitor or not is controlled, input and output voltage gains are changed by changing and controlling the duty ratio of the power switch tube and the turn ratio of the coupling winding, and the output voltage gains are output by the output circuit. According to the invention, by changing the turn ratio of the three-winding coupling inductor, the boost conversion of the output voltage to the DC power supply voltage is realized, the condition of a limit duty ratio can be effectively avoided, and the conversion function of the high output voltage is realized by using a relatively small duty ratio; due to the fact that the structure can effectively reduce voltage stress of devices in the circuit, loss is reduced, and the overall working efficiency of the circuit is improved.

Description

technical field [0001] The invention belongs to the technical field of DC-DC conversion equipment, and in particular relates to a high voltage gain DC-DC converter. Background technique [0002] At present, high-gain DC-DC boost converters are widely used in new energy fields, including photovoltaic systems, wind power generation, and fuel cells. However, the DC voltage level generated by resources such as photovoltaics and FCs is low, which is not suitable for grid integration. According to the above-mentioned problems, a high-boost DC-DC converter is required to increase the output DC voltage level of such resources. [0003] In recent years, various boost DC-DC converters with boost technology have been proposed. The isolated converter utilizes a transformer with a large turns ratio and has a high voltage conversion ratio. However, an excessive turn ratio will lead to excessive leakage inductance, thereby reducing converter efficiency and increasing switch voltage stre...

AI Technical Summary

Problems solved by technology

However, low voltage conversion ratio, semiconductor high-voltage stress, and reverse recovery issues are fundamental issues for this converter in high-power applications.

Literature "A.Ajami, H.Ardi, and A.Farakhor, A novel highstep-up DC-DC converter based on integrating coupled inductor and switched-capacitor techniques for renewable energy applications, IEEE Trans.PowerElectron., vol.30, no .8, pp.4255–4263, Aug.2015." and "M. Eskandarpour Azizkandi, F. Sedaghati, and H. Shayeghi, An interleaved configuration of modified KYconverter with high conversion ratio for renewable energy applications; design, analysis and implementation, J.Oper.Autom.Power Eng., vol.7, no.1, pp.90–106, 2019.” proposed switched inductor (SL) and switched capacitor (SC) converters, which have high gain However, the circuit is complex and the current stress is large

Literature "X.Hu, J.Wang, L.Li, and Y.Li, A three-winding coupled-inductorDC-DC converter topology with high voltage gain and reduced switch stress, IEEE Trans.Power Electron., vol.33, no.2, pp.1453–1462, Feb.2018.” and literature “K.C.Tseng, J.T.Lin, and C.C.Huang, High step-up converter with three-windingcoupled inductor for fuel cell energy source applications, EEE Trans.PowerElectron. , vol.30, no.2, pp.574–581, Feb.2015.” proposed several high-boost DC-DC converters based on three-winding coupled inductors, the adjustment of voltage stress and voltage gain is more flexible, however Gain is not high enough

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