Cascaded step-down DC-DC converter

Abstract

The invention relates to a cascaded step-down DC-DC converter. The cascaded step-down DC-DC converter comprises a capacitor energy storage module 1, a capacitor energy storage module 2, ... a capacitor energy storage module n, an inductor L1, an inductor L2, ... an inductor Ln+1, and a capacitor Co, wherein the capacitor energy storage module j comprises a diode Dj_1, a capacitor Cj_1, a diode Dj_2 and an electronic switch Sj, the electronic switch Sj comprises a diode Dj_3, an N type MOS transistor Mj_1, and a controller j, wherein j is between 1 and n. Working characteristics of the cascadedstep-down DC-DC converter are as follows: the converter has a simple circuit structure, is easy to expand, can be controlled by diversified methods, and is efficient, input and output currents are continuous, output and input voltages are common-grounded and are consistent in polarity, and an output voltage Vo is less than or equal to a DC power supply voltage Vi.

Description

technical field [0001] The invention relates to a DC-DC (DC-DC) converter, in particular to a cascaded step-down DC-DC converter with continuous input and output currents and the same polarity of input and output voltages, which can be used as a high-voltage step-down Compared with the basic unit to build a multi-input and multi-output DC power system, such as: DC power module parallel system, LED array drive system, distributed photovoltaic power generation system, etc. Background technique [0002] The existing basic DC-DC converters with step-down function include Buck converter, Buck-Boost converter, Cuk converter, Sepic converter and Zeta converter. As listed in Table 1, without considering the output capacitor, none of the above five basic DC-DC converters with step-down function satisfies the requirement of "continuous input and output currents and the same polarity of input and output voltages". Require. [0003] [0004] Table 1 [0005] Cascading is a common ...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the current discontinuity in the combination of Speic and Buck and the combination of Speic and Zeta in the existing step-down DC-DC converter cascading scheme of "the input and output currents are continuous and the input and output voltages are of the same polarity" Problems and the combination of Cuk and Cuk have the problem that the input and output are not common ground. The present invention provides a cascaded step-down DC-DC converter, which can realize continuous current between stages and common ground between input and output, so that Expansion of cascaded types of DC-DC converters

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