Quadratic Boost converter with low capacitance voltage stress

Abstract

The invention discloses a quadratic Boost converter with low capacitance voltage stress. The quadratic Boost converter comprises a DC voltage source, two inductors, a switching tube, three diodes, twocapacitors and a load. The drain of the switching tube is connected with one end of the second inductor. The anode of the second diode is connected with the cathode of the third diode. The anode of the first capacitor is connected with the cathode of the first diode, the other end of the second inductor and the cathode of the second capacitor. One end of the first inductor is connected with the anode of the first diode and the anode of the third diode. The anode of the second capacitor is connected with the cathode of the second diode and one end of the load. The positive electrode of the DCvoltage source is connected with the other end of the first inductor and the cathode of the first capacitor. The negative electrode of the DC voltage source is connected with the source of the switching tube and the other end of the load. The first inductor and the second inductor operate in the CCM mode. The converter has only one switching tube and has the characteristics of high gain and low capacitance voltage stress so as to be especially suitable for high voltage and high power application occasion.

Description

technical field [0001] The present application relates to the field of electrical technology, in particular to a secondary boost converter with low capacitor voltage stress. Background technique [0002] Since the output voltage of DC power sources such as photovoltaic cells, fuel cells, and storage batteries is low, even lower than 48V, and for AC220V grids, the input of half-bridge and full-bridge grid-connected inverters is generally DC760V and DC380V. Voltage conversion is one of the main problems to be solved in renewable energy grid-connected power generation systems. [0003] When the working duty cycle D approaches 1, the gain of the basic Boost converter tends to be infinite in theory, but there are the following problems in practical engineering applications: ①The voltage and current stress of the switch tube and diode are large; ②The switching loss , Diode reverse recovery loss is large, resulting in low conversion efficiency; ③ dv / dt is large, resulting in serio...

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Problems solved by technology

[0003] When the working duty cycle D approaches 1, the gain of the basic Boost converter tends to be infinite in theory, but there are the following problems in practical engineering applications: ①The voltage and current stress of the switch tube and diode are large; ②The switching loss , The reverse recovery loss of the diode is large, resulting in low conversion efficiency; ③The dv / dt is large, resulting in serious electromagnetic interference (EMI); ④The ability to resist input voltage disturbance and the dynamic performance are poor

However, the voltage stress of the capacitor is the same as that of the original cascaded system, which is much higher than the input voltage, which increases the difficulty of capacitor selection and reduces the system efficiency

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