Study on broadband loss characteristics of oil-immersed papers for fast transient modeling of power transformer

Abstract

In order to complete the broadband simulation model of power transformer, and establish a systematic and complete model for studying fast transient interaction between transformer and power system, the frequency dependent characteristics of dielectric losses in power transformer were investigated. Several typical insulation structures in power transformers were considered and measuring techniques determined to study the dielectric losses. Frequency dependent dielectric losses in the range of 10-10 7 Hz were measured by a dielectric spectroscopy analyzer produced by Novocontrol. The characteristics of insulating papers and pressboard measured in the air and after immersing in the mineral oil were compared. Based on the dielectric relaxation theory, the number of dielectric relaxation was determined according to the measured data, and four typical model functions were adopted to fit the data and the consistency of fitting by these functions were compared and physical explanations of fitting parameters were described. Finally, a quantitative description of frequency dependent characteristics of insulation losses was proposed for improving the transformer simulation model. . His research interests focuses on circuits and systems, dielectric response of transformer insulation, frequency dependent loss of power transformer and electromagnetic transient modeling and simulations.Zan-ji Wang (SM'01) received the B.S., M.S., and Ph.D. degrees in electrical engineering

Quantitative Analysis of the Sensitivity of UHF Sensor Positions on a 420 kV Power Transformer Based on Electromagnetic Simulation

“…Here, ε' is the real component of permittivity and ε" is the imaginary component of the permittivity. A first-order Debye model function, as shown in Equation (2), was used to obtain complex permittivity [21].…”

“…Therefore, it is necessary to identify if sensors installed at these positions are still the most sensitive when the PD sources are inside the winding. The sensors corresponding to these locations are sensors 1, 4, 5, 8, 9, and 12 on the HV side and sensors 13,16,17,20,21, and 24 on the MV/LV side. From Table 2, it can be observed that most of these sensors have four PD sources from which they receive signals that are below the threshold.…”

A Modified Aging Kinetics Model for Aging Condition Prediction of Transformer Polymer Insulation by Employing the Frequency Domain Spectroscopy

“…is regarded as the reference temperature (different operating or thermal aging temperature), t ref (t) is the time (hours) required for the chemical reaction to reach a certain aging degree at the temperature of T ref (T). Review the Arrhenius theory, which is utilized to interpret the variation law between chemical reaction rate and reaction temperature [17,18] as is shown in Equation (16).…”

“…In literature [14,15], the integral value of the FDS curve is computed and applied as the feature parameter for achieving the above goal. In addition, the equivalent circuit model that is capable of analyzing the corresponding aging condition is also reported, such as the Cole-Cole model [16], the Havriliak-Negami model [17], the Davidson-Cole model [18], and the Dissado-Hill model [19]. However, it is a fact that the contribution of the aging condition on measured FDS data could be easily covered by the moisture effect [13][14][15].…”

Moisture Prediction of Transformer Oil-Immersed Polymer Insulation by Applying a Support Vector Machine Combined with a Genetic Algorithm

“…One is based on extracting the feature parameters 2 of 17 from the dielectric response curves [11,[15][16][17]. The other is realized by establishing the equivalent circuit model to extract the feature parameters of dielectric response property [18,19]. The above methods could extract the feature parameters, reflecting the moisture inside oil-immersed insulation.…”