Five-level power converter, and control method and control device for five-level power converter

Abstract

The invention provides a five-level power converter, a control method and a control device for the five-level power converter. The five-level power converter comprises an inverter and at least one rectifier, wherein the rectifier comprises at least one rectification control circuit and four capacitors which are connected in parallel in pairs; the first ends of the first capacitor to the fourth capacitor are common-grounded; the rectification control circuit is used for inputting a current to the second ends of the first capacitor to the fourth capacitor respectively; the polarity of the charges accumulated at the second end of the first capacitor and the second end of the second capacitor is opposite to that of the charges accumulated at the second end of the third capacitor and the second end of the fourth capacitor; the inverter comprises a discharge control circuit, and a first inductance unit and a first load which are connected in series with each other; the discharge control circuit is used for discharging from the second ends of the four capacitors of the rectifier in sequence; discharge current flows through the first induction unit and the first load which are connected in series; and the charging and the discharging of any of the first capacitor to the fourth capacitor are staggered.

Description

technical field [0001] The invention relates to power conversion technology, in particular to a five-level power converter and its control method and control device. Background technique [0002] An uninterruptible power system (Uninterruptible Power System, UPS) is a constant-voltage constant-frequency power converter that contains an energy storage device, with a rectifier and an inverter as its main components. It is mainly used to provide uninterrupted power supply to a single computer, computer network system or other power electronic equipment. When the mains input is normal, the UPS will stabilize the mains and supply it to the load. At this time, the UPS is equivalent to an AC mains voltage stabilizer, and it also charges the internal energy storage device; when the mains is interrupted, The UPS immediately uses the electric energy stored in the internal energy storage device to continue to provide AC power to the load through the method of inverter conversion, so t...

AI Technical Summary

Problems solved by technology

[0004] Power converters in the prior art can only perform four-level power conversion and output four-level voltage

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