Isolated direct current converter applicable for medium-voltage direct current system and control method thereof

Abstract

The invention discloses an isolated direct current converter applicable for a medium-voltage direct current system and a control method thereof. The direct current converter is of a modularized combined structure for a plurality of power modules through serial connection during input and parallel connection during output, and each power module consists of a switching circuit and an isolated switching circuit cascade connection. Each switching circuit consists of a switching switch, a switching power device and a short circuit prevention diode, and is used for controlling the switching and elimination of the corresponding control module, so that redundant operation and rapid fault isolation of the system are realized; when an external fault appears, the fault can be quickly eliminated, andwhen an internal fault of the module appears, the fault module can be quickly eliminated, so that normal operation of the converter is guaranteed; simultaneously, input and output voltage matching ofeach module can be guaranteed, so that the stress of voltage and current on the power device is reduced; and after the fault is eliminated, the converter also can be quickly used. The converter disclosed by the invention is high in reliability and long in service life, and is applicable for the applications such as long-distance underwater electric energy supply, interconnection of direct currentmicrogrids with different voltage levels and electrolytic aluminum and sea water desalination industries.

Description

technical field [0001] The invention relates to a DC converter, in particular to a structure of a high-reliability isolated DC converter suitable for a medium-voltage DC power supply system and a control method thereof. Background technique [0002] In the context of the transformation of the global energy landscape, DC power transmission and power distribution technology based on DC microgrids has become a solution to effectively utilize distributed renewable energy such as wind and light. Therefore, the interconnection between DC microgrids of different voltage levels is very important. ; On the other hand, traditional marine military, scientific research work and metal manufacturing industry and other energy supply places with special needs need adaptive power supply devices. The above application scenarios have the characteristics of high power supply, poor operating environment, and low maintainability. Therefore, the requirements for equipment reliability are high, and...

AI Technical Summary

Problems solved by technology

The above application scenarios have the characteristics of high power supply, poor operating environment, and low maintainability. Therefore, the reliability of the equipment is high, and a system design with high voltage level, high precision, and redundant operation capability is required to meet the requirements.

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