Intermediate capacitive step-up DC converter with three input sources and method

Abstract

The invention discloses an intermediate capacitive step-up DC converter with three input sources and a method thereof. The DC converter includes a first input power source, a second input power source, a third input power source, and a stage I buck-boost circuit , Class II buck-boost circuit, Class III buck-boost circuit and Class IV buck-boost circuit; the first input capacitor is connected in parallel with the first input power supply; the positive pole of the second input power supply is connected to the first output capacitor and the second input capacitor The connection point is connected, the negative pole of the second input power supply is connected to the connection point of the third input capacitor and the second output capacitor, and the fourth input capacitor is connected in parallel with the third input power supply; the I-level buck-boost circuit controls the first input power supply to the first The output capacitor transfers energy, the grade IV buck-boost circuit controls the third input power to transfer energy to the second output capacitor, the grade II buck-boost circuit and the grade III buck-boost circuit control the distribution of the second input power to the first output capacitor and the second output capacitor 2. The size of the energy of the output capacitor to balance the output voltage of the DC converter.

Description

technical field [0001] The invention relates to the technical field of power electronic power conversion, in particular to an intermediate capacitive step-up DC converter with three input sources and a control method thereof. Background technique [0002] Since the 21st century, the problem of energy crisis has become more and more serious, and renewable energy has become a hot research topic in various countries. Common new energy power generation grid-connected converters have single-stage and two-stage structures. The single-stage structure has a simple topology and low cost, but requires a higher input power supply voltage to meet the grid-connected voltage requirements. The cascaded structure can improve the controllability of the grid-connected system through the boost and energy management of the pre-stage structure, but the additional structure will increase the cost and introduce loss. [0003] In order to reduce costs and improve efficiency, two-stage converters b...

AI Technical Summary

Problems solved by technology

The traditional interleaved parallel boost circuit connects two boost circuits in parallel to reduce the current flowing through each device and increase the capacity of the converter, but this structure does not change the voltage stress of the device, so it is difficult to apply to higher voltage levels

With the increase of the voltage level, the three-level boost circuit is widely used because it can reduce the voltage stress of the device to half of the output voltage, but its boost ratio is the same as that of the traditional boost circuit, and the voltage gain is not high enough, and Device current stress remains high

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