Magnetic characteristics of the iron cores affect significantly the steady and transient performances of the transformers. Due to nonlinear and multi-values characteristics, modeling of the hysteresis behavior of a magnetic material is principally complicated. In general the conventional methods yield to inaccurate results , particularly when are employed to model a transient phenomena. Scalar ...

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...

Transformer fault diagnosis and repair is a complex task that includes many possible types of faults and demands special trained personnel. Moreover, the minimization of the time needed for transformer fault diagnosis and repair is an important task for electric utilities, especially in cases where the continuity of supply is crucial. In this paper, Stochastic Petri Nets are used for the simula...

With the application of the articulated phase insulator, and the speed of electric locomotive rising, it is inevitable for the electric locomotive to adopt the technology automatic passing through the electric phase separation. However, when the locomotive passes the electric phase separation, a variety of overvoltages will be generated, such as the cut-off overvoltage and the closing overvolta...

The main purpose of this study is to analyze the current leakage of the power grid due to the change in speed of high-speed rail (HSR). First, using PSIM software as the fundamental basis, this study constructed an overall HSR circuit-based model system, including Scott transformer, auto-transformer, and the track equivalent circuit and grounding system. In addition, this paper sought to study ...

Transformers are widely used in electric power system to perform the primary functions, such as voltage transformation and isolation. So the transformer design is emphasize. In this paper, a transformer design optimization method is proposed aiming at designing the transformer to optimize the efficiency and cost. The design optimization of transformer is formulated as unconstrained non linear m...

A voltage transformer, as voltage signal detection equipment, plays an important role in a power system. Presently, more and more electric power systems are adopting potential transformer and capacitance voltage transformers. Transformers are often large in volume and heavyweight, their insulation design is difficult, and an iron core or multi-grade capacitance voltage division structure is gen...

Power transformers are important and expensive components in the electric power system. The knowledge of the actual status of the transformer insulation behavior, load tap changer performance, temperature, and load condition is necessary in order to evaluate the service performance concerning reliability, availability and safety. Systems abnormalities, loading, switching and ambient condition n...