Neutral point clamp three-level unipolar current module

Abstract

The invention provides a neutral point clamp three-level unipolar current module, and belongs to the field of electric power electronic technology and electric power transmission and distribution. As for the internal arrangement of the module, the emission electrode of a first full-control switching device and the collection electrode of a second full-control switching device are connected at a first point, and the collection electrode of the first full-control switching device is connected with the anode of a first diode unit to act as a first port; the emission electrode of a third full-control switching device and the collection electrode of a fourth full-control switching device are connected at a second point, and the emission electrode of the fourth full-control switching device is connected with the cathode of a second diode unit to act as a second port; the cathode of a first capacitor and the anode of a second capacitor are connected at a third point; and the cathode of the first diode unit and the collection electrode of the third full-control switching device are correspondingly interconnected with the anode and the cathode of the first capacitor, the anode and the cathode of the first diode are respectively connected with the first and third points, and the anode and the cathode of the second diode are respectively connected with the third and second points. The neutral point clamp three-level unipolar current module is suitable for the application occasion of unipolar current and has less number of required switching devices in comparison with other modules having the same number of level so that the neutral point clamp three-level unipolar current module has the characteristics of being economical in cost and compact in structure.

Description

technical field [0001] The invention belongs to the field of power electronics technology and power transmission and distribution, and in particular relates to a neutral-point clamped three-level unipolar current module. Background technique [0002] Modular multilevel converters have the advantages of good current harmonic characteristics, active and reactive power decoupling control, modular design, and easy fault-tolerant operation. Power compensation, motor variable frequency drive and other fields have been widely used. [0003] The operating characteristics of a modular multilevel converter depend on the circuit structure of the internal modules. The traditional half-bridge module structure has the advantages of less loss and lower cost, but because it cannot provide negative level voltage, it cannot transmit power at low voltage on the DC side, nor can it limit the fault current after a short-circuit fault on the DC side. In addition, the bridge arm voltage of the b...

AI Technical Summary

Problems solved by technology

However, the two controllable switching devices in the diagonal bridge module are distributed in the diagonal positions of the module, so the controllable switching devices can only use a single device module, and cannot use a more integrated Dual-pipe module is not conducive to the integrated design of the module

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