MMC (Modular Multilevel Converter)-based bidirectional direct-current converter and control system thereof

Abstract

The invention belongs to the field of power electronics and provides an MMC (Modular Multilevel Converter)-based bidirectional direct-current converter. The converter comprises a first direct-currentport, a second direct-current port, a plurality of first MMC modules, a plurality of second MMC modules, a plurality of first capacitors, a second capacitor, a first inductor and a second inductor; the first end of the first inductor is connected with the first electrode of the first direct-current port; the plurality of first MMC modules are connected in series to form a first series branch; theplurality of second MMC modules are connected in series to form a second series branch; the first end and second end of each first capacitor are respectively connected with the second ends of the first MMC module and the second MMC module, the series connection sequence of the first MMC module being identical with the series connection sequence of the second MMC module; the second end of the second inductor is connected with the first electrode of the second direct-current port; and the second ends of the first capacitors and the second capacitor are connected with the second electrode of thesecond direct-current port; the first inductor and the second inductor are positively coupled and share a magnetic core. The switching loss of the converter is effectively reduced, and the output voltage level of the converter is improved.

Description

technical field [0001] The invention relates to the technical field of power electronic devices, in particular to an MMC-based bidirectional DC converter and a control system thereof. Background technique [0002] In today's society, environmental and energy issues have become the focus of attention of countries all over the world. Under the influence of the rapid development of various new energy and renewable energy, the power system is developing towards the hybrid energy field of comprehensive application of new energy such as fuel cells, photovoltaic power generation, and wind power generation. bigger. Nowadays, bidirectional converters have been widely used in battery charging and discharging, electric vehicle on-board power supply, DC uninterruptible power supply system, aviation energy, solar photovoltaic power generation system and other fields. [0003] However, existing bidirectional DC converters have disadvantages such as large switching loss, low overall effi...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above-mentioned problems in the prior art, that is, in order to solve the technical problems such as large switching loss, low overall efficiency, and low output power level of the existing bidirectional DC converter, the present invention provides a bidirectional DC converter based on MMC and its Control System

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