Bridge arm current decoupling control method for modularization multi-level converter

A modular multi-level, control method technology, applied in the direction of electrical components, output power conversion devices, etc., can solve problems such as bridge arm current fluctuations, reduce bridge arm current fluctuations, improve reliability and operating efficiency, The effect of strong controllability

CN103036410AActive Publication Date: 2013-04-10INST OF ELECTRICAL ENG CHINESE ACAD OF SCI
1 Cites 4 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2013-04-10

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a bridge arm current decoupling control method for a modularization multi-level converter. The control method includes the steps of controlling common mode components of current of bridge arms in the operating process of the modularization multi-level converter, and adding an energy limited condition in the process of controlling the common mode components of the current of the bridge arms so as to ensure that the sum of stored energy by capacitors in an upper bridge arm submodule and a lower bridge arm submodule is constant. The energy limited condition is that the sum of the energy instantly passing through current common mode components of the bridge arms and flowing into the capacitors in the upper bridge arm submodule and the lower bridge arm submodule is equal to the sum of the energy flowing out of the upper bridge arm submodule and the lower bridge arm submodule through differential mode components and flowing to an alternating current side. A set value of the current common mode components of the bridge arms is calculated according to the limited conditions and then is added into a control system so as to enable the current of the bridge arms to be smooth and reduce current fluctuation of the bridge arms.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a control method of a multilevel power electronic converter. Background technique

[0002] Modular Multilevel Converter (MMC) is a new type of power electronic converter that has recently received widespread attention. It was first proposed by A. Lesnicar and R. Marquardt in Germany around 2002. The modular and cascadable structure of the modular multilevel converter determines that it is especially suitable for the application of medium-voltage to high-voltage power electronic conversion. Relevant research institutions at home and abroad have done a lot of research on the control method of modular multilevel converters.

[0003] Such as figure 1 As shown, the basic topology of the three-phase modular multilevel converter is composed of three-phase six bridge arms, and each phase has two upper and lower bridge arms. Each bridge arm is formed by cascading a bridge arm inductor and several sub-modules with the same structure. ...

Examples

Embodiment

[0059] The implementation effects of the present invention will be described below in conjunction with the examples, but the present invention is not limited by the specific examples.

[0060] In this embodiment the converter operates at a frequency of 50 Hz.

[0061] Figure 4 When the control method of the present invention is not added, the three-phase alternating current waveform and the current waveform of the upper and lower bridge arms of phase A can be seen from the waveform diagram, the upper and lower bridge arm current oscillation amplitude is relatively large, and the peak value of the bridge arm current reaches 320A.

[0062] Figure 5 After adding the control method of the present invention, the three-phase alternating current waveform and the upper and lower bridge arm current waveforms of A phase can be seen from the waveform diagram, the upper and lower bridge arm currents are obviously smooth, the oscillation amplitude becomes smaller, and the peak value of ...