Isolation transformer

About: Isolation transformer is a research topic. Over the lifetime, 8145 publications have been published within this topic receiving 72396 citations.

Isolation transformer arrangement

Abstract: An isolation transformer arrangement comprises an isolation transformer (17) having magnetically coupled primary (25) and secondary (18) winding arrangement wherein one of either the primary (25) or the secondary (18) winding is formed of at least one planar conductive trace formed on an associated face of an insulating substrate (29-32) of a printed circuit board (19) and the other (25) is formed of a plurality of turns of an insulated wire conductor. The printed circuit board (19) has also provided thereon one or more discreet electric components arranged in two electrically separate circuits (20; 21) each circuit connectable to a respective one of the primary (2; 25) and the secondary (3; 18) windings of the isolation transformer (1; 17) in which the insulation of the wire conductor winding (25) is adapted to provide a desired level of electrical isolation between the circuits (20; 21) necessary for use in medical equipment.

Transformer protection system

Abstract: In a transformer protection system, data of voltages and currents detected at individual terminals of a transformer connected to an electric power system are supplied to a computer. The computer computes driving point admittances or shunt admittances of the transformer on the basis of the voltage and current data and predetermined transfer admittances of the transformer and decides that an internal fault has occurred in the transformer when the values of the driving point admittances or shunt admittances deviate from pre-set reference values, thereby disconnecting the transformer from the electric power system.

Design and implementation of a bidirectional isolated dual-active-bridge-based DC/DC converter with dual-phase-shift control for electric vehicle battery

Abstract: The electric vehicles become an alternative to gasoline driven cars nowadays which calls for the technological progress on EV battery charger. This paper presents a bidirectional isolated Dual-Active-Bridge-based DC/DC converter with dual-phase-shift control for a Li+Fe battery system of the EV application. The dual-phase-shift control strategy provides two degree of freedom to control the transmitting power and improve the performance of the DAB converter. In order to reduce the switching loss and the hysteresis loss of the isolating transformer, the control strategy is designed to minimize the peak transferring current flowing on the transformer. Theoretical analysis and control implementation are described. A LABVIEW-based prototype is established to verify effectiveness.

Axial vibration analysis of transformer windings with hysteresis of stress-and-strain characteristic of insulating materials

Abstract: This paper deals with the method of calculating the axial vibration of power transformer windings under short circuit conditions. The hysteresis phenomenon is taken into consideration for the stress-and-strain characteristic of insulators in calculating the axial vibration. In order to obtain the hysteresis axes, a repeated load test for typical insulating materials is carried out. At the same time, the influence that compressive speed extends to the modulus of longitudinal elasticity is studied. Measured curves are expressed as a numerical formula and included in the developed method. This method is applied to axial vibration analysis of various transformers that have been normally operating on site, and the relationship between hysteresis characteristics and axial forces, which are compressive force and external thrust force, is discussed in detail. As a result, the proposed method is shown to be a useful means for the axial vibration analysis of transformer winding.

Apparatus for producing a plasma and hand-held device having the apparatus

Abstract: The invention relates to an apparatus (1) for producing a plasma (P), comprising a control circuit (3) which is electrically connected to a piezoelectric transformer in order to excite the piezoelectric transformer (5). The invention further relates to a hand-held device (100) that uses the apparatus (1). The piezoelectric transformer (5) is constructed of several layers (S1, S2,..., SN). The control circuit (3) is implemented on a circuit board (7), and the piezoelectric transformer (5) is held over the circuit board (7) by means of a region (6B) of a first end (6). A high voltage is applied to a second free end (8) of the piezoelectric transformer (5), wherein the plasma (P) is produced at atmospheric pressure.