Combining modern high-power semiconductor devices with constantly improving magnetic materials opens up the possibility to replace bulky low-frequency transformers with a new medium voltage medium frequency conversion structure. While there are still challenges to be addressed related to these so called power electronic transformers, a steadily increasing development effort is evident and consi...

This article presents a simple and rather precise method for analysis and design of a transformer-coupled input rectifier with a filter capacitor, which is used as a power supply for electronic circuits. It is based on an original logarithmic equation that determines the conduction angle of the rectifier diodes as a function of the transformer equivalent resistance. This equation can replace th...

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...

In this paper a modular power electronic transformer (PET) for feeding critical loads is presented. The PE based transformer is a multi-port converter that can connect to medium voltage levels on the primary side. Bidirectional power flow is provided to the each module. The presented structure consists of three stages: an input stage, an isolation stage, and an output stage. The input current i...

Electrical Engineering (ABSTRACT) In a conventional electronic ballast for a fluorescent lamp, inductor-capacitor-transformer tank circuit is used. A Piezoelectric Transformer (PT) can potentially be used to replace such a tank circuit to save space and cost. In the past, ballast design using a PT requires selecting a PT from available samples which are normally not matched to specific applicat...

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...

Abstract—The purpose of this paper is to propose a novel generalized single-band transformer for two arbitrary complex load and source impedances and a novel high-power amplifier using this new transformer. By adding two reactive parts at across terminals, the coupled line with flexible electrical length has practical evenand odd-mode characteristic impedances. Thus, the total circuit layout ca...

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 ...