H-bridge five-level active neutral point clamped inverter and dead zone effect suppression method

Abstract

The invention discloses an H-bridge five-level active neutral point clamping inverter. The inverter is formed by connecting a left bridge arm and a right bridge arm of a five-level active neutral-point clamped topological structure, the two ends of a direct-current bus of the left bridge arm and the two ends of a direct-current bus of the right bridge arm are connected in parallel and then connected with a first voltage-dividing capacitor Cd1 and a second voltage-dividing capacitor Cd2 respectively, and the first voltage-dividing capacitor Cd1 and the second voltage-dividing capacitor Cd2 areconnected in series. The invention also discloses a dead zone effect inhibition method. The switching state of a high-voltage tube within the dead time of a voltage zero-crossing point is maintained in the previous state, and a follow current path in dead time is changed, so that the 5L-ANPC inverter outputs zero level in the dead time, the multi-level override jump problem caused by the dead effect at the zero crossing point of the output voltage of the active neutral point clamped five-level H bridge is inhibited, and the requirement on the output load dv / dt is reduced.

Description

technical field [0001] The invention belongs to the technical field of converter control, and in particular relates to an H-bridge five-level active mid-point clamping inverter and a dead-zone effect suppression method thereof. Background technique [0002] Multilevel converters have the advantages of high power factor, low switching loss, low harmonic content, low dv / dt, etc., and have been widely used in new energy grid connection, AC speed regulation, DC power transmission and other fields. Compared with the traditional diode-clamped and flying-capacitor inverters, the five-level active neutral-point-clamped inverter does not require a large number of clamping diodes and clamping capacitors, and it is easy to achieve balanced control of capacitor voltages. , the complexity of the control system is low and is receiving more and more attention. [0003] The dead time introduced to prevent the power supply from passing through will cause the multi-level leapfrog phenomenon ...

AI Technical Summary

Problems solved by technology

[0003] The dead time introduced to prevent the power supply from passing through will cause the multi-level leapfrog phenomenon at the zero-crossing point of the output voltage of the five-level active neutral point clamped H-bridge inverter, and the multi-level leapfrog phenomenon will cause Excessively high dv / dt, which puts forward higher design requirements for the main circuit absorption circuit and output filter, and is not conducive to the insulation of loads such as motors

[0004] At present, the existing research literature increases the volume, cost and control complexity of the system by using additional hardware to increase the freewheeling path.

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