Diode clamping five-level dual buck half-bridge inverter

Abstract

The invention discloses a diode clamping five-level dual buck half-bridge inverter which comprises a first five-level buck circuit, a second five-level buck circuit, a direct current power input circuit and a load circuit. The inverter is controlled by adopting voltage-current dual closed loop SPWM (Sinusoidal Pulse Width Modulation), the two five-level buck circuits are controlled to work withina half cycle according to the direction of inductive current and the magnitude of output voltage, and five-level PWM (Pulse-Width Modulation) wave output is obtained respectively on two output bridgearms through different switch combination. The invention has the advantages that the advantages of straight through without bridge arms of the dual buck circuits and diode reverse recovery without switching tube are reserved; five-level output is realized, and the harmonic wave content of output voltage is reduced, thus the size of a filter can be reduced, the switching frequency of a PWM part can be reduced, the switching loss can be reduced, and the efficiency can be improved; compared with a half-bridge type inverter, the voltage stress of power devices is reduced so that a switching device of medium or low power is suitable for occasions of high voltage and high power; and only eight power diodes are needed in the circuits, compared with a five-level diode clamping inverter, the quantity of the diodes is reduced by 1/3, and a clamping circuit is simplified.

Description

1. Technical field [0001] The invention relates to an inverter, in particular to a diode-clamped five-level double-buck half-bridge inverter. 2. Background technology [0002] Dual Buck Inverter (hereinafter referred to as DBI) is a new type of inverter topology that has emerged in recent years. Compared with the traditional bridge inverter, DBI has the unique advantages of high reliability without bridge arm direct connection and no reverse recovery problem of parasitic diode of switch tube; DBI working in half-cycle mode has no circulating current, which is to realize the inverter at the same time The high-frequency and high-efficiency provide a simple way, and it is a topological structure with great research value and development prospects. DBI and half-bridge inverters have many similarities, and they will be referred to as half-bridge inverters below. The half-bridge inverter needs an external positive and negative DC bus voltage, whose amplitude is more than twice t...

AI Technical Summary

Problems solved by technology

Due to the limitation of device manufacturing technology, the withstand voltage of power semiconductor devices has a certain limit

In high-voltage converters, power tubes can be used in series, but due to the inconsistency of device parameters and asynchronous switching transients, it is difficult to achieve voltage equalization in the steady state and transient process, resulting in overvoltage of individual power tubes, reducing the circuit reliability

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