This paper presents the general knowledge, theory and methodology of life management that used in electric power transformer. The paper also discusses the basic failure theory and method to establish failure model of power transformer. Insulation ageing is a problem due to dielectric, chemical, thermal and electro-mechanic stresses, which is highly depending on operational conditions. Life mana...

This paper proposes a Flexible Power Electronic Transformer (FPET) for the application in the micro-grids. The low frequency transformer is usually used at the Point of Common Coupling (PCC) to connect the low voltage grid and utility network to each other. The conventional 50Hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. In this pap...

this work studies the effect of neutral earth resistance on the controlling ferroresonance oscillation in the power transformer including MOV surge arrester. A simple case of ferroresonance circuit in a three phase transformer is used to show this phenomenon and the three-phase transformer core structures including nonlinear core losses are discussed. The effect of MOV surge arrester and neutra...

In this paper, a new model based on the thevenin equivalent circuit for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the transformer is considered. The ultra-saturation phenomenon causes the mal-operation of the power transformer differential protection. So, the description a...

Transformer is the power equipment of power system core. Intelligent monitoring and operation of transformer can not only monitor the full range of the transformer, the realization of state evaluation, it should be required repair, maintenance required good, but also on the latent fault early diagnosis and prediction. Research on transformer intelligent monitoring and operating technology of sa...

Power transformer is a core equipment of power system, which undertakes the important functions of power transmission and transformation, and its safe and stable operation has great significance to the normal operation of the whole power system. Due to the complex structure of the transformer, the use of single information for condition-based maintenance (CBM) has certain limitations, with the ...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...

The power transformer is one of the most important equipment in a power system. Optimal design of transformer involves determination of design parameters of a power transformer when a chosen objective is optimized, simultaneously satisfying a set of constraints. In this paper Simulated Annealing (SA) is used for optimization of Power Transformer Design (OPTD).The total mass of core and copper i...

The modeling of power transformer faults and its application to performance evaluation of a commercial digital power transformer relay are the objective of this study. A new method to build an EMTP/ATP power transformer model is proposed in this paper. Detailed modeling of the transformer relay is also discussed. The transient waveforms generated by ATP under different operating conditions are ...