Electric Field And Distribution Of The Impulse Voltage Emulational Analysis In The 1000kV UHV Step-up Transformer

Ultra high voltage AC step-up transformer will be used to increase the generating voltage directly to 1000 kV. So it will be very significant to reduce the middle step-up equipments and save soil resource and project cost.The best design has been chosen after transportation feasibility and high reliability have been considered, and several design plans have been analyzed in this paper for the ultra high voltage step-up transformer, the type of which is DFP-400000/1000.The main insulation configuration design for ultra high voltage step-up transformer is one of the most important and difficult problems. Enough main insulation margin is required in order to assure the reliable operating of transformer, but the insulation margin shall not be too much owing to economical cost by decreasing the transportation size and weight. So how to economically and reliably design the insulation configuration is very important. Electric field in several key parts has been calculated and analyzed by finite element analysis software in this paper. Electric field strength values, insulation margin and minimal oil gap have also been confirmed in this paper, which provided the reference basis for insulation design.The longitudinal insulation configuration design for ultra high voltage step-up transformer is another one of the most important and difficult problems. Also enough margin is required for the longitudinal insulation configuration, and it is important to design a scientific and reliable longitudinal insulation configuration. The electric potential distribution and the electric potential gradient distribution under the action of the lightening full wave and chopped wave impulse have been calculated by professional wave process calculation software in this paper. The minimal safety margin for longitudinal insulation has been obtained, which provided the basis for design.Research and calculation for the main and longitudinal insulation in this paper provided the reference basis for the develop of ultra high voltage transformer.