DESIGN OF MODULATION CONTROLLER TO DAMP POWER OSCILLATIONS OF PARALLEL AC LINE IN THE TIANSHEBQIAO TO GUANGDONG HVDC TRANSMISSION

摘要

Tianshenqiao Hydro Station is located at Guangxi Province. Its ultimate installed capacity is 2520mw (6×220mw+4× 300mw). Tianehenqiao to Guangdong HVDC transmission llne is the second DC line in China, it will operate in 1996. The DC line is about 960km, transferee 1800 mw power to Guangdong through the DC line. By the end of 1996, there are one 500kv AC line and one ±500kv DC line interconection between Guangxi and Guangdong system.By appropriate modulation of power order on HVDC transmission system the transient stability performance of the integrated AC/DC power system can be improved greatly, as shown by considerable amount of theoretical work already published in this area. The 1800mw Tiansheqiao to Guangdong HVDC transmission will be provided with the HVDC power modulation feature intended to stabilize the AC power system.In a transmission system which has both AC and DO line running in parallel thepower order to the HVDC can be modulated in order to reduce the power swings in the AC line and thus increase the stability limit of the integrated AC/DC system. The power modulation for Tianshenqiao to Guangdong HVDG transmission was carried out by BPA prorram which was developed by Bonneville PowerAdministration in U.S.A.. Comprehensivedigital computer studies show the importance of the power modulation for the Tianshenqiao to Guangdong HVDC transmiation.This paper describes the results of thestudy carried out to design the powermodulator for the Tianshenqiao to Guangdong HVDC transmission system. It shows how the transient stability limit can be increased by power modulation on BVDC.