Modular high-voltage transmission ratio direct-current transformer topological structure and control method

Abstract

The invention relates to the field of direct-current transformers, in particular to a modular high-voltage transmission ratio direct-current transformer topological structure and a control method. The topological structure is composed of a high-voltage filter capacitor CHV, a high-voltage filter inductor LHV, a high-voltage side thyristor, N power module groups, a low-voltage filter inductor LLV and a low-voltage filter capacitor CLV. Each power module group comprises an input port and an output port, and the N power module groups are connected with the high-voltage side thyristor, the high-voltage filter inductor, the high-voltage filter capacitor and the low-voltage filter capacitor after being connected in series in input to form a high-voltage direct-current port; and the N power module groups are connected with the low-voltage filter inductor and the low-voltage filter capacitor after being connected in parallel in output to form a low-voltage direct-current port. Compared with a traditional direct-current transformer, the topological structure has the advantages of being small in number of modules, low in cost and small in size, and the direct-current transformer topological structure can achieve direct-current voltage conversion with the high transmission ratio by using only a small number of half bridges, so that the cost of the direct-current transformer is reduced, and the power density is improved.

Description

technical field [0001] The invention relates to the field of direct current transformers, in particular to a modular high voltage transmission ratio direct current transformer topology and control method. Background technique [0002] With the popularization of renewable energy such as photovoltaics and wind energy and the rapid development of DC transmission and distribution technology, the interconnection of DC transmission and distribution networks with different voltage levels and structures has become a development trend. DC transformers can connect DC transmission and distribution networks of different voltage levels, improving the flexibility and reliability of DC transmission and distribution, and its importance has become increasingly prominent. The MMC structure has the advantages of modularization and good fault handling capabilities, and is widely used in high-voltage direct current transmission and power electronic transformers and other occasions. When the DC ...

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Problems solved by technology

[0003] In order to solve the deficiencies mentioned in the above-mentioned background technology, the purpose of the present invention is to provide a modular high voltage transmission ratio DC transformer topology and control method, which solves the problem of high voltage transmission ratio DC transformers in the case of medium and high voltage DC bus interconnection. , the number of modules is large, the problem of high cost and large volume

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