Direct current transformer and high-frequency link voltage matching phase-shifting modulation method thereof

Abstract

The invention discloses a direct current transformer and a high-frequency link voltage matching phase-shifting modulation method thereof. The direct current transformer comprises one or more than onebridge modules, each bridge module comprises a first transmission unit, a second transmission unit and a high-frequency isolation transformer connected between the first transmission unit and the second transmission unit, and a first switch device, a second switch device, a third switch device and a fourth switch device in the first transmission unit form a first full-bridge circuit; a fifth switch device is connected with a first capacitor in series, and the fifth switch device and the first capacitor which are connected in series are connected with the first switch device in parallel; a sixth switch device is connected in series with a second capacitor, and the sixth switch device, the second capacitor and the third switch device which are connected in series are connected in parallel. The direct current transformer has the bidirectional fault current blocking capability, and the power supply reliability of the whole power grid is improved by adopting the phase-shifting modulation method.

Description

technical field [0001] The invention belongs to the field of power electronics, in particular to a DC transformer and a high-frequency link voltage matching phase-shifting modulation method thereof. Background technique [0002] In the networking process of the medium and high voltage DC grid, the DC transformer is an important link to promote its development. Since the traditional DC transformer does not have or only has the ability to block the unidirectional fault current, when it is applied to the DC grid, it will be affected. The impact of the DC fault current from the DC grid is damaged, which affects the safe operation and reliable power supply of the DC transformer itself and the DC grid. Therefore, how to enable the DC transformer to have a bidirectional fault current blocking function is an urgent problem to be solved. Contents of the invention [0003] In view of the above problems, the present invention provides a DC transformer and its high-frequency link vol...

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Problems solved by technology

[0002] In the networking process of the medium and high voltage DC grid, the DC transformer is an important link to promote its development. Since the traditional DC transformer does not have or only has the ability to block the unidirection

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