.2015 Years Of Cloud Power To Send The Guangdong Section Transient Safety Analysis

With the western development strategy and the implementation of the strategy that electricity from western to eastern in China Southern Power Grid, relying on construction of large-scale hydropower base, Yunnan's hydropower resources have been fully progressive development and utilization. By 2015, according to China Southern Power Grid "twelveth five-year plan"development planning, three UHVDC±800kV lines will be building, which are separately from Chuxiong in Yunnan Province to Guangzhou Huidong; from Xiluodu to Qingcheng Tonghe; from Nuozhadu to Jiangmen Shunde. DC transmission capacity will meet 17800MVA.Yunnan Power Grid's generation capacity will increase from the current 2221 million kilowatts to 41.72 million kilowatts, and Yunnan routing outgoing transmission line section is now "four AC and one DC" to "seven AC and three DC".Outgoing load will increase from 21951MVA to 7800MVA. The bulk power transmission from Yunnan province to Guangdong province will have a rapid development in the next few years.The bulk power transmission from Yunnan province to Guangdong province system is AC/DC parallel system, which is constituted with the 500kV EHV transmission system and the DC±800kV UHV system. DC system will be integrated into the original AC system, so it forms of AC/DC parallel systems. With HVDC technology widely used in China, the AC/DC parallel system will become the main form of the bulk power transmission from Yunnan province to Guangdong province and network interconnection, the bulk power transmission from Yunnan province to Guangdong province as a large scale AC/DC parallel transmission system is the first time appearance in our country, and it will bring enormous economic benefits to us, at the same time it will bring a series of technical and management problems, as well as some potential problems, that is more unpredictability increase in the operation of power grids. Therefore, in order to ensuring safe and stable operation of the system and giving full play to their potential for transmission, it has important significance to careful study of the Multi Infeed AC/DC parallel transmission system characteristics, to multiple AC/DC parallel transmission system simulation, to research the exchange interaction and mutual influence of AC/DC parallel transmission system, and to master the characteristics and law of AC/DC parallel systems.In this paper, the FASTEST as a simulation tool to analyze transient safety of the bulk power transmission from Yunnan province to Guangdong province system under great abundance power resource for the China Southern Power Grid in 2015. And it calculated the transient power angle stability margin, the transient voltage security margin, and the transient frequency safety margin, when the HVDC system had occurred single pole block and double pole block. According to results, the paper analyzed the feasibility of long-term operation, when a single pole block had happened in the HVDC bulk power transmission from Yunnan province to Guangdong province. It also analyzed the leading to instability of the critical power systems group, as well as the cutting machine to be taken measures when the double pole block take place in the HVDC bulk power transmission from Yunnan province to Guangdong province. And it analyzed the impact of DC closed on the transmission power of AC channels. Through the limits search calculation, the DC bulk power transmission from Yunnan province to Guangdong province was separately exerted the DC and AC three-phase short circuit fault. when the power system was under various fault, the power angle transient stability limit clearing time CCT, transient voltage stability limit clearing time CCT, transient removal of time limits the frequency stability of CCT were calculated for the protection of the setting value to provide the necessary reference. For three-phase short circuit of AC transmission system in the bulk power transmission from Yunnan province to Guangdong province, the transient safety margin was calculated. According to calculations curve, the paper analyzed the impact on the DC power transmission system, as well as on the DC system for phase converter, when the bulk power transmission from Yunnan province to Guangdong province had occurred failure.