交流特高压在中国应用的经济和安全分析研究

Economy and security analysis of AC UHV in China

就交流特高压在我国远距大容量输电、区域网互联和特高压网3个应用范围进行了安全性和经济性分析,在直流高压(包括背靠背)、交流500kV和特高压3种方案之间展开比较。结合有关特高压文章中不同观点进行讨论,结论是在3种不同应用范围,与直流高压(包括背靠背)、交流500kV比较,交流特高压在经济和安全方面都没有优势。其中,远距大容量输电在600km及以上优选直流高压输电,600km以下优选交流500kV,在接近600km和大于7000MW以上的输电容量可在500kV与特高压之间进行比较选择。交流互联因扩大同步网降低了安全稳定性,直流背靠背互联可提高安全性但投资较大,需根据不同情况进行优选。特高压网的互联经济效果与其它方式的互联效果差别不大,若再考虑投资因素,可推荐超高压网+直流和超高压输电+背靠背或超高压互联模式。建议积极展开提高我国超高压网利用率的研究。

The economy and security analysis of AC UHV in China is carried out in three applications：long- distance large- capacity transmission,regional grid interconnection and UHV network,which is compared among three schemes：DC high-voltage（including back-to-back）,AC 500 kV and UHV. Combined with different views in some relative references,it is concluded that, compared with the other two schemes,the AC UHV has no superiority in both economy and security for all three applications. DC high- voltage scheme is the better choice for 600 km and above transmission distance while AC 500 kV for less than 600 kin. For about 600 km distance and over 7 000 MW transmission capacity,comparative selection between 500 kV and 1 000 kV may take place. AC interconnection enlarges ＂the synchronous power grid but lowers security,while DC back-to-back interconnection improves the security but increases investments. The economic effect of UHV network is nearly same as other interconnection modes. With the consideration of investment,it is recommended to adopt EHV network ＋ DC and EHV transmission ＋ back-to-back or EHV interconnection. It is suggested to carry out the research for improving the usage efficiency of EHV network in China.