Buck-boost low-stress switched capacitor multi-level inverter

Abstract

The invention discloses a buck-boost low-stress switched capacitor multi-level inverter, which can work in a boost mode and a buck mode, and can enable the voltage stress of all switching devices to be smaller than the input voltage. The inverter comprises a pre-stage switched capacitor unit, an extensible switched capacitor unit and a post-stage switched capacitor unit. The number of the extensible switched capacitor units can be zero or more; Boost and buck conversion are integrated, the input voltage range of the system is expanded, the flexibility of the inverter system is improved, and the inverter system can be independently applied to inductive loads.

Description

technical field [0001] The invention belongs to the field of multilevel inverters, and in particular relates to a voltage-boosting low-stress switched capacitor multilevel inverter. Background technique [0002] High frequency is one of the development directions of power electronics in the future. High-frequency AC power distribution system (HFAC PDS) has been widely used in aerospace, computer communication and other fields due to its advantages of high reliability, high efficiency and small size. In the field of electric vehicles, compared with the traditional integrated power supply and distributed power supply, HFAC PDS has the advantages of high transmission efficiency, low manufacturing cost, and saving vehicle space; the application of HFAC PDS in the field of microgrid can more effectively integrate distributed power supplies. Renewable energy... With the development of new material semiconductor devices, power electronics technology, control technology and informa...

AI Technical Summary

Problems solved by technology

Traditional multi-level inverters include diode clamp type, flying capacitor type and cascaded H-bridge type, but their structure is complex, the number of power devices is large, and the voltage stress is high, while the switched capacitor inverter is a good solution To solve this problem, the number of power devices and the number of capacitors used by the switched capacitor inverter are much smaller than those of the traditional multi-level inverter in the case of the same output level

In the research of switched capacitor inverters, most topologies can only perform one of the functions of step-up or step-down, which limits the range of input DC voltage sources (such as photovoltaic power generation, energy storage batteries) and reduces the flexibility of the system.

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