Compact voltage source converter system suitable for direct-current distribution network

Abstract

The invention provides a compact voltage source converter system suitable for a direct-current distribution network. The compact voltage source converter system comprises a plurality of two-level sub-modules, a plurality of LC filters, a multi-winding transformer, a master control device and a plurality of slave control devices. The alternating current side of each two-level sub-module is connected to a low-voltage side winding of the multi-winding transformer through one LC filter, and a high-voltage side winding of the multi-winding transformer is connected with an external alternating current system. The direct current side of the two-level sub-module is connected in series between a positive direct current bus and a negative direct current bus, each slave control device is connected with one two-level sub-module, and the master control device is connected with all the slave control devices. According to the invention, the cost is reduced, the occupied area is greatly reduced, the integration level is high, the maintenance difficulty is low, the circuit is simple, the number of used devices is small, the structure is compact, the loss is low, and the power transmission efficiency is high. The main control device adopts a control protection architecture of a compact master-slave architecture combining control and protection and canceling valve control, so that the compactnessand the economy are achieved.

Description

technical field [0001] The invention relates to the technical field of direct current distribution networks, in particular to a compact voltage source converter system suitable for direct current distribution networks. Background technique [0002] Compared with traditional DC transmission technology, flexible DC transmission uses full-control devices instead of half-control devices, which can realize independent control of active power and reactive power; realize passive AC system power supply; filter capacity is small, small footprint, convenient for modules It is especially suitable for grid-connected new energy power generation, island power supply, asynchronous interconnection of AC systems, grid-connected distributed power generation, DC power grid, and urban power distribution. In recent years, with the accumulation of experience in the application of flexible DC transmission technology in the high-voltage field, coupled with the development of distributed energy and ...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the disadvantages of high cost, large floor space, low integration and difficult maintenance in the above-mentioned prior art, the present invention provides a compact voltage source converter system suitable for DC distribution network, including multiple secondary Ping sub-module, multiple LC filters, multi-winding transformer, master control device and multiple slave control devices; the AC side of each two-level sub-module is connected to the low-voltage side winding of the multi-winding transformer through an LC filter, the The high-voltage side winding of the multi-winding transformer is connected to the external AC system; the DC side of the two-level sub-module is connected in series between the positive DC bus and the negative DC bus; each slave control device is connected to a two-level sub-module, and the master control device is connected to all slaves The master control module is used to generate control instructions through the information of the two-level sub-module obtained from the slave control module, and sends the control instructions to the corresponding slave control device; the slave control module is used to obtain the information of the two-level sub-module Information, and control the two-level sub-module based on the control command, which reduces the cost, greatly reduces the occupied area, high integration and low maintenance difficulty

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