CASCADE CONVERTER STATION AND MULTI-END CASCADE HVDC POWER TRANSMISSION SYSTEM

摘要

A cascade converter station and a multi-end cascade high-voltage direct current (HVDC) power transmission system. The converter station includes a low-voltage end converter station (11) and a high-voltage end converter station (12). Each electrode of the low-voltage end converter station (11) includes a converter transformer (111a, 111b) coupled to a first alternating current (AC) power grid, a converter valve (112a, 112b) coupled to the converter transformer (111a, 111b) and smooth reactors (115a, 115b). The high-voltage end converter station (12) connected in series with the low-voltage end converter station (11) through a medium-voltage direct current (DC) power transmission line (13) and connected to a HVDC power transmission line (14). Each electrode of the high-voltage end converter station (12) includes a converter transformer (121a, 121b) coupled to a second AC power grid, a converter valve (122a, 122b) coupled to the converter transformer (121a, 121b) and smoothing reactors (125a, 125b). A ground electrode line (126) and a metal return line (128) are provided in the low-voltage end converter station (11). A ground electrode line (133) and neutral bus switches (140a, 140b) can be further provided in the high-voltage end converter station (12). With the cascade converter station and the multi-end cascade HVDC power transmission system, HVDC power transmission can be achieved in a flexible, reliable and economical manner.