A h-bridge five-level active neutral-point clamp inverter and dead-zone effect suppression method

Abstract

The invention discloses an H-bridge five-level active neutral-point clamp inverter, which is formed by connecting left and right bridge arms of a five-level active neutral-point clamp topological structure, and the DC bus bars of the left and right bridge arms After the two ends are connected in parallel, the first voltage dividing capacitor C is connected respectively d1 and the second divider capacitor C d2 , the first divider capacitor C d1 and the second divider capacitor C d2 series; also discloses its dead zone effect suppression method, by maintaining the switching state of the high voltage tube in the previous state during the dead zone time of the voltage zero crossing point, changing the freewheeling path during the dead zone time, so that the dead zone time is 5L‑ The ANPC inverter outputs zero level, which suppresses the problem of multi-level leapfrog jump caused by the dead zone effect at the zero-crossing point of the active neutral point clamped five-level H-bridge output voltage, and reduces the impact on the output load dv / dt Require.

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 voltage. , 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 a...

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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