Calculation And Analysis Of Short-circuit Windings Electromagnetic Force On The Ultra-high Voltage Transformers

The transient electromagnetic field, transient short-circuit, short-circuitelectromagnetic force are calculated and analyzed using the finite element methodduring the single-phase short-circuit in transformer such as a three-phaseautotransformer type of SFPZ10-240000/330.Some abilities for transformer windingto withstand short-circuit are validated based on standard of national. A fewachievements with values on theory and engineering have been gained，referentialrules are provided to calculated and validated for the winding short-circuitelectromagnetic force of large、ultra high voltage power transformers。The thesis consist of three parts, In the first part introduction the development of powertransformer in our country, transformer short-circuit accident situations in recent years, anddiscusses the purpose and significance of ultra high voltage power transformers windingsshort-circuit electromagnetic force calculation; Describes both at home and abroad on shortcircuit testing, electromagnetic and magnetic flux leakage, short-circuit the electromagneticforce simulation software as well as winding intensity survey; electromagnetic field theory、Finite element analysis and MagNet software were introduced at the same time account of themajor work done in this paper.Second part, puts forward the calculation method of the transient electromagneticfield,transient short-circuit and short-circuit electromagnetic force. Using MagNet software atransformer single-phase short circuit calculation finite element model has been established,simulation the transformer short-circuit test state, to take the high voltage is applied before thelow-voltage in circuit mode. transient electromagnetic field,transient short-circuit andshort-circuit electromagnetic force were calculated and analyzed. The axial and radialmagnetic leakage field distribution of the winding, current waveform of short circuit, radialand axial electromagnetic force distribution of each winding unit were gained, Within0.25s,The stress of wire winding unit were calculated when short-circuit.The third part, select one power transformer model of SFZ11-120000/220which passed the short circuit test. A method to an example product anti shortcircuit ability was verified provided by GB1094.5-2008, Results showed that theexample has enough ability to withstand short circuit.