Flexible loop closing device based on H-bridge five-level topological structure

Abstract

The invention provides a flexible loop closing device based on an H-bridge five-level topological structure. The flexible loop closing device comprises a first step-down transformer, a second step-down transformer, a first dual-port module, a second dual-port module and a third dual-port module, a primary winding of the first step-down transformer is connected with a first three-phase alternating current power grid, and a secondary winding of the first step-down transformer is a mutually isolated three-phase power supply and is connected with first alternating current sides of the first dual-port module, the second dual-port module and the third dual-port module respectively; the primary winding of the second step-down transformer is connected with a second three-phase alternating current power grid, and the secondary winding of the second step-down transformer is a mutually isolated three-phase power supply and is respectively connected with the second alternating current sides of the first dual-port module, the second dual-port module and the third dual-port module; the direct current sides of the first dual-port module, the second dual-port module and the third dual-port module are connected in parallel, the number of levels is large, the distortion rate of network access current is low, and the requirement for a filter is low.

Description

technical field [0001] The invention relates to the field of power distribution, in particular to a flexible loop closing device based on an H-bridge five-level topological structure. Background technique [0002] The medium-voltage distribution network is mainly based on a single power supply radial or partitioned power supply mode based on "closed-loop design and open-loop operation". During open-loop operation, the power flow between different partitions cannot provide support, and it is difficult to ensure uninterrupted power supply for users when a partition grid fails. With the rapid economic development, customers have higher and higher requirements on the reliability of power supply. In the medium and low voltage distribution network, in order to avoid power outages caused by line maintenance and operation mode changes, ensure uninterrupted power supply for important users, and improve the reliability of the distribution network, it is necessary to perform loop clos...

AI Technical Summary

Problems solved by technology

It has high-frequency isolation function, but does not have power frequency isolation function, and the equipment cost is relatively high

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