Application of Large- Capacity Transmission Techniques

Transcription

1 Application of Large- Capacity Transmission Techniques Wang yimin State Grid Corporation of China Washington DC May 30,

2 1. Overview of UHV AC & DC Transmission projects Project Construction Time Operation Time Jindongnan-Nanyang-Jingmen 12/ /2009 Huian-Shanghai 10/ /2013 Zhebei-Fuzhou 04/ /2015 Hami Yunnan-Guangdong 12/ /2010 Xiangjiaba-Shanghai 12/ /2010 Jinping-Sunan 12/ /2012 Hami-Zhengzhou 05/ /2014 Xiluodu-Zhexi 07/ / MW/2210km Jindongnan Legend 1000kV AC,Commercial operation 1000kV AC,Under construction ±800kV DC,Commercial operation ±800kV DC, Under construction Jinping Xiangjiaba Xiluodu Yunnan 7200MW/2059km 5000MW/1373km 2*3000MVA 640km Nanyang Jingmen 8000MW/1680km Zhengzhou Sunan Huinan MVA 2 656km Guangdong Zhebei Fuzhou Shanghai Shanghai 6400MW/1907km Zhexi MVA 2 603km 2

3 2. Application Why choose AC 1000kV? Based on economical analysis and other methods, 1000kV is more economical than 500kV when the transmission capacity is more than 4000MW and transmission distance is longer than 500km 500kV 1000kV 3

4 2. Application DC Transmission Selection The critical economical transmission distances are determined using the unit capacity annual cost method kv ±1100 ±800 Capacity:3500MW Current:3500A Conductor Cross Section: Power Loss rate: <3.6% Capacity :10000MW Current :5000A Conductor Cross Section :8 900 Power Loss rate :3.7%~6.3% ±660 ±500 Capacity :4600MW Current :3500A Conductor Cross Section : Power Loss rate :3.0%~3.7% Capacity :8000MW Current :5000A Conductor Cross Section : Power Loss rate :3.1%~5.5% km Economical Transmission Distance and Line Loss for the four voltages 4

5 Transmission Capacity(MW) 2. Application AC or DC? who applicable? AC or DC are determined considering the different transmission characteristics and the impact factors such as economic, security, reliability, environmental etc DC ± 1100kV AC 1000kV DC ± 800kV AC 500kV DC ±660kV DC ± 500kV Transmission Distance(km)

6 3. Development goal Increase capacity Raise the DC current up to 6250A and the voltage up to ±1100kV Northeast power grid 2015 grid " T wo vertical and two horizontal" AC pathways and seven DC lines F orm the North-China Tibet power grid Northwest power grid North China-Central China -East China power grid. Legend 1000kV AC Back to back DC ±800kV DC ±660kV DC ±500kV DC ±400kV DC Central-China East-China UHV synchronous grid Southern power grid 6

7 Overview of ±1100kV DC development Completed project conceptual system design and released technical specifications. Proposed the mode of UHVDC hierarchical connection to 500kV and 1000kV AC system. Raise the current of UHVDC to 6.25kA Completed the manufacture of the Model prototype of converter transformer and valve. both passed the test evaluation. Completed the development of DC field switches including disconnector, earthing switch, transfer switch and the manufacture of the prototypes, most of switches passed the test evaluation. 7

8 DC transmission capacity: with 5 inches thyristor current 3kA ±500kV ±800kV capacity=2x500kvx3ka=3000mw capacity=2x800kvx3ka=4800mw with 6 inches thyristor 4kA 4.5kA 5kA 6.25kA 800kV 6400MW 7200MW 8000MW 10GW 1100kV 11GW 13.75GW research in progress 8

9 The design scheme of ±1100kV DC DC hierarchical connection for capacity 10GW and above 9

10 To raise DC current to 6.25kA Research shows no critical equipment problem. Converter transformer, valve and thyristor, smoothing reactor, and DC field equipments are OK. But the valve side bushing is a key problem. (ABB,ALSTOM 5kA OK) Converter transformer transportation is more difficult. the way to resolve is modular transportation and on-site assembly. 10

11 112 t 78m 62t 63m ±1100kV DC Tower Based on the research result on electromagnetic environment, mm2 mended conductor recom ±800kV ±1100kV 11

12 ±1100kV DC Bushing The converter transformer valve side bushing (15.6m, 7.9t ) The wall bushing ( 25.5m, 6.6t ) 12

13 ±1100kV DC transformer Estimated size: 14000(length) 4050(width) 5050(height): Total weight: 450t Converter transformer model prototype 1 Estimated size: 12000(length) 4800(width) 5900(height) Total weight: 650t. Converter transformer model prototype 2 13

14 ±1100kV DC Valve Three manufacturers completed the design and manufacture of the ±1100kV valve prototype, all passed the test evaluation XD-valve prototype C-EPRI-valve prototype XJ-valve prototype 14

15 ±1100kV DC Switches Completed the development of DC field switches, most of which passed the test evaluation XD-disconnector test Pinggao-disconnector test Pinggao-earthing switch test 15

16 Thank you 16