Vienna rectifier midpoint potential low-frequency oscillation suppression modulation method

Abstract

The invention discloses a Vienna rectifier midpoint potential low-frequency oscillation suppression modulation method, which comprises the following steps of: firstly, providing a novel simplified algorithm to obtain action time of each basic vector based on equivalent space vector modulation realized by dual carriers; and then, by adding a neutral-point potential balance compensation factor into a zero-sequence component of dual-carrier modulation, on the basis of realizing neutral-point potential balance by adjusting action time of positive and negative redundant small vectors, investigating a middle vector and a non-redundant small vector, analyzing the influence of the middle vector and the non-redundant small vector on the neutral-point potential, optimizing the neutral-point potential balance compensation factor, and middle-point potential low-frequency oscillation caused by the middle vector and the non-redundant small vector is suppressed. The midpoint potential low-frequency oscillation suppression modulation method is provided for the Vienna rectifier, the problem of midpoint potential low-frequency oscillation is effectively solved, and the system stability is improved.

Description

technical field [0001] The invention relates to a low-frequency oscillation suppression modulation method for a Vienna rectifier (Vienna rectifier), which belongs to the power electronics technology. Background technique [0002] The Vienna rectifier is a three-level topology with unidirectional energy transmission. Compared with the three-level neutral point clamped (Neutral Point Clamped, NPC) topology, it has simple structure, high power density, and no dead zone in the bridge arm. Due to its simple driving scheme and other advantages, it has received extensive attention in the front-end application of electric vehicle charging equipment. However, due to the characteristics of the inherent topology of the Vienna rectifier, there are problems of midpoint potential imbalance and low-frequency oscillation on the DC side, which will increase the voltage stress of the power switching device and affect the operating life and reliability of the DC side capacitor. [0003] The t...

AI Technical Summary

Problems solved by technology

However, due to the characteristics of the inherent topological structure of the Vienna rectifier, there are problems of midpoint potential imbalance and low-frequency oscillation on the DC side, which will increase the voltage stress of the power switching device and affect the operating life and reliability of the DC side capacitor.

[0003] The traditional space vector modulation will introduce a large number of trigonometric function operations, which will increase the complexity of the modulation algorithm. At the same time, the traditional space vector modulation is to achieve the neutral point potential balance by adjusting the action time of the positive and negative small vectors, while ignoring the medium vector due to uncontrollable The impact on the midpoint potential, while also ignoring the impact of the non-redundant small vectors included in the two-level space voltage vector distribution diagram corresponding to the large sector on the midpoint potential, which will cause low-frequency oscillations in the midpoint potential

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