Asymmetric input multi-level convert device and control method

Abstract

The invention provides an asymmetric input multi-level converter device, which comprises a switched capacitor unit X and a full bridge unit Y, wherein the switched capacitor unit X comprises a first DC input voltage source Vin1, a second DC input voltage source Vin2, a first electrolytic capacitor C1, a first diode D1, a second diode D2, a third diode D3, a first switch tube S1, a second switch tube S2, a third switch tube S3, and a fourth switch tube S4; and the full bridge unit Y includes a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, and an eighth switch tube S8.The invention also provides a control method for the converter device. More-level output with fewer devices can be realized, the driving circuit required by the converter device is simplified, the making cost of the converter device is reduced, the converter device provided in the invention has multiple input ports, and the application in a multi-input source situation is more flexible.

Description

technical field [0001] The invention relates to the field of distributed power generation and micro-grid, in particular to an asymmetric input multi-level converter and a control method. Background technique [0002] In recent years, with the increasing environmental pollution and energy shortage, new energy power generation has attracted more and more attention. Photovoltaic, wind power and other forms of power generation have been recognized as ideal substitutes for fossil energy due to their environmental friendliness and good economic benefits. In order to make new energy more widely used, scholars at home and abroad have proposed a series of new inverters from the perspectives of improving output power quality, reducing total loss, and reducing the size of output filters and transformers. Among them, the multilevel inverter is more and more widely used by virtue of its unique advantages. Compared with the output waveform of traditional inverters, this type of inverter...

AI Technical Summary

Problems solved by technology

The traditional diode-clamped inverter has the problem of unbalanced bus capacitor voltage, and an additional hardware clamp circuit can balance the capacitor voltage, but this will increase the number of power devices and the cost of the inverter to a certain extent; A large number of clamping capacitors are required in the transformer

A large number of capacitors increases the volume and manufacturing cost of the inverter; the H-bridge cascaded inverter is formed by cascading multiple independent DC power supply H-bridge inverters, and the same structure and control method in the inverter are convenient System expansion, but as the number of output levels continues to increase, the number of DC power supplies and switching devices will increase significantly

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