High-gain converter for photovoltaic direct-current module and control method of high-gain converter

Abstract

The invention belongs to the technical field of converters, and discloses a high-gain converter for a photovoltaic direct-current module and a control method of the high-gain converter. The positive electrode of an input filter capacitor of the converter is connected with one end of a first inductor and one end of a second inductor; the other end of the first inductor is connected with the drain electrode of the first switch tube and the positive electrode of the first capacitor; the other end of the second inductor is connected with the drain electrode of the second switch tube, the anode of the second diode and the cathode of the second capacitor; the source electrode of the second switch tube is connected with the cathode of the first capacitor and the anode of the first diode; the cathode of the second diode is connected with one end of the third inductor and the anode of the third capacitor; the other end of the third inductor is connected with the anode of the third diode and the anode of the second capacitor; and the cathode of the third diode D3 is connected with the anode of the output filter capacitor. The high-gain converter has the advantages of being high in boosting capacity, few in power tubes, small in input current ripple and the like.

Description

technical field [0001] The invention belongs to the technical field of converters, and in particular relates to a high-gain converter for photovoltaic DC modules and a control method thereof. Background technique [0002] Inverter is a key component of photovoltaic grid-connected power generation system, which is mainly divided into centralized, string, AC module (ie micro-inverter), parallel DC module (ie power optimizer) and other types. The first two types of inverters have high conversion efficiency, but require a large number of photovoltaic modules to be used in series and parallel. Under the condition of partial shading, it will be difficult to find the global maximum power point due to the multi-peak phenomenon of the P-V characteristic curve of the photovoltaic array. Unleash the power generation potential of each component. Micro-inverters can realize the maximum power point tracking control at the component level, and have the advantages of flexible installation,...

AI Technical Summary

Problems solved by technology

Boost converters based on coupled inductors can obtain higher voltage gain by changing the winding ratio of coupled inductors, but the conversion efficiency is usually low due to the difficulty of effectively recovering leakage inductance energy

The multi-module extended switched inductor Boost converter changes the connection mode of the inductor by controlling the switch off and on, so as to obtain a higher voltage gain; however, there are a large number of power devices, and the voltage stress of the power devices is high. Low efficiency and other disadvantages

Moreover, the input current has a large pulsation, and a large-capacity filter capacitor needs to be connected in parallel on the input side, resulting in a large system size, cost, and low reliability.

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