Space vector modulation method of multi-source converter

A technology of space vector modulation and converter, applied in vector control system, electronically commutated motor control, control system, etc., can solve problems such as unproposed midpoint potential, imbalance, and poor harmonic performance

CN110768598AActive Publication Date: 2020-02-07BEIJING JIAOTONG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2020-02-07

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Abstract

The invention provides a space vector modulation method of a multi-source converter, and belongs to the technical field of pulse width modulation of the multi-source converter. The space vector modulation method comprises the steps of building a neutral point potential unbalance space vector model by combining a standard right-angle coordinate system; dividing a small vector into a first vector group and a second vector group, and determining a boundary equation of a small sector comprising small vectors in the first vector group and the second vector group; determining a reference voltage vector according to the boundary equation of the small sector; calculating an action time proportion of a basic vector of the small sector; and performing hybrid modulation on the first vector group andthe second vector group according to the action time proportion so as to achieve DC-side power allocation and acquire various energy circulation modes. The problem brought by neutral point voltage unbalance is solved by a coordinate operation-based method, and the operation quantity is reduced; and hybrid modulation of the first vector group and the second vector group is employed, power allocation of a DC side is achieved by controlling action time weights of the first vector group and the second vector group, and more energy circulation modes are obtained.
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Description

technical field

[0001] The invention relates to the technical field of pulse width modulation of multi-source converters, in particular to a space vector modulation method of multi-source converters. Background technique

[0002] Space Vector Pulse Width Modulation (SVPWM) is a modulation technology that controls the converter based on the space voltage (current) vector switching of the converter. The ideal flux circle of the stator of the relative symmetry motor is used as the reference standard, and different switching modes of the converter are used to switch the space voltage vector, and the actual magnetic flux generated is to approach the reference circular magnetic flux, and the switching of the converter is determined by the result of their comparison. Form PWM waveform. Compared with the direct SPWM technology, its main advantages include a higher degree of harmonic optimization, improved voltage utilization and dynamic response speed of the motor, and is suitable ...

Examples

Embodiment

[0076] Such as Figure 6 As shown, the embodiment of the present invention provides a space vector modulation method for a multi-source converter proposed by the present invention. The current SVPWM algorithm is discarded so that the AC side of the multi-source converter can obtain a three-level output phase voltage, and the AC output harmonic can be improved. Wave performance; use coordinate calculation method to solve the problem caused by the unbalanced midpoint voltage, and reduce the amount of calculation; use vector group 1 and vector group 2 mixed modulation, by controlling the action time weight of vector group 1 and vector group 2 , can realize the power distribution of the DC side, and obtain more energy flow modes.

[0077] The multi-source converter topology is as figure 1 As shown, the three-level output phase voltage obtained on the AC side is the voltage relative to the neutral point. Taking one of the phase bridge arms as an example, the two independent energy...