TECHNICAL FEASIBILITY AND RESEARCH & DEVELOPMENT NEEDS FOR ± 1000 kV AND ABOVE HVDC

摘要

There Here is considerable experience on 500/600 k' dc system available world wide and lot of learning's are also available JL now during development and recent operation of SOU kl' dc system. During ll)7()'s and iSO's. anticipating the next stage ojhigh power HVDC transmission, considerable studies and field tests pertaining to Corona Studies. Insulation System Insulator Pollution Tests etc was taken up by EPRI/ other international institutions up to -1200 k V dc system. However, due to saturation-Mfload-growth.furtherResearchund-Devclopment in Ultra High Ibliage (L'M'i area were slowed down or virtually stopped. With high surge of Energy requirement of geographically large countries coupled with large population and steep economic development incountries like China, India. Brazil and Africa etc. the situation has changed and these developing countries have shown high interest for harnessing remote hydro resources. This necessitates large transmission systems with UHVdc and ac to transmit largeblock of power to a distant load centre. It is a fact that dc phenomena is complex and different than UHV ac in regard to it's pollution performance, reliabilityof converter transformers, harmonics, ground return mode operation etc. The existing knowledge of electrical withstand in air, oil and other materials for voltages 2000-3000 kV is not enough neither for AC, DC, lightning or switching impulse, particularly not at high altitudes(2000-4000 mi where some of the future potential transmissions are going to be built However, thanks to the ongoing development of better insulating materials for pollution, super thermal upgraded papers for transformer insulation, better quality transformer oils, .split air core reactors, high energy capability surge arrestors and technology up gradation in civil engineering for cheaper in door switch yard etc which may facilitate 1000 kV development.