Research On Transient Process Of Winding Model With Subsection And Layer Structure Under Narrow Pulse Voltage

Prebreakdown and restrike, which results in very fast transient over voltage (VFTO), will occur, when disconnector and breaker belonged to GIS are opening or closing.It's of great significance to complete the work for the reduction of transformer faults and the assurance of power system operation in safety,which include to establish equivalent circuit and calculate potential distribution and gradient distribution,parameters of the transformer winding with subsection and layer structure,since the harm of the VFTO for transformer.As follows are completed in this paper.According to the model structure of the winding with subsection and layer structure,a lumped parameter model by single layer winding unit is brought forward.The related parameter values of the inductance calculation equation are analyzed.The measurement values by the inductance tester are consistent with the calculation values of the parameters in an actual winding model.Transient process of the equivalent circuit of winding with subsection and layer structure is calculated by mesh analysis method,the narrow pulse voltage which waveform parameters are 0.1/5μs and 10/100ns are applied on the equivalent circuit of winding, according to the voltage waveforms which calculated through each unit,potential distribution and gradient distribution of all the windings unit are fitted.According to the equivalent circuit of the winding and transient process calculation method,the narrow pulse voltage which waveform parameters are 0.1/5μs and 10/100ns and response voltage are transformed to frequency-domain in order to obtain the voltage transfer function and amplitude-frequency characteristic.Through virtual front time is 10ns and 450V voltage produced by high voltage pulse generator, the voltage waveforms of each unit of winding with subsection and layer structure are measured,potential distribution and gradient distribution with all of winding units are fitted.The voltage transfer function and amplitude-frequency characteristic are calculated by input voltage and response voltage.