Isolation transformer

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

Coreless printed-circuit board transformers for signal and energy transfer

Abstract: The authors describe the optimal use of a printed-circuit board transformer with minimum power consumption. The proposed transformer is much smaller than a standard pulse transformer and is suitable for both signal and energy transfer. It can be operated in the megaHertz frequency range. With the use of modulation/demodulation circuits it can be used for digital signal transmission over a wide frequency range from DC to /spl sim/300 kHz. The proposal can replace core-based transformers in many low power applications.

Contactless energy transmission for an isolated 100W gate driver supply of a medium voltage converter

Abstract: In this paper, an innovative DC-DC converter is investigated which provides electrical power to the gate driver units of medium voltage level converters. For the discussed DC-DC converter, a galvanic isolation (isolation voltages of up to 35 kV) is required. This electrical isolation is achieved with a coreless transformer in order to obtain a cost-effective solution. Furthermore, the DC-DC converter contains a full-bridge converter being operated with low switching losses, a resonant compensation network to achieve a high overall efficiency and an output side rectifier. In this paper, the design of the coreless transformer, the appropriate compensation networks and the power electronics are discussed in detail. Moreover, measurement results obtained from a 100 W prototype, operated at a switching frequency of 410 kHz, are presented. With the proposed setup, a high overall efficiency of up to 80% and a transformer breakdown voltage of 55 kVrms is achieved. Thus, the proposed converter concept represents a very competitive solution with respect to the typically employed DC-DC converters with dry-type cast coil transformers.

2 MHz power converter with piezoelectric ceramic transformer

Abstract: A power converter with a new piezoelectric transformer is presented. The piezoelectric transformer, made of lead titanate solid solution ceramic, is operated with a thickness extensional vibration mode. This transformer can operate at high frequency, over several megahertz, with about 90% efficiency. The resonant frequency for the transformer is 2 MHz. The power converter with the transformer applies the theory for a class-E switching converter using an electromagnetic transformer. Maximum output power is obtained when the switching frequency is slightly higher than the resonant frequency. A 4.4 W output power is successfully obtained with 52% efficiency at 2.1 MHz switching frequency. >

High frequency transformer design for modular power conversion from medium voltage AC to 400V DC

Abstract: The paper presents a high frequency modular medium voltage AC (4160 VAC and 138 VAC) to low voltage DC (400 VDC) power conditioning system block (PCSB) that are scalable so that they can be used for micro grids of different scale (several-hundred kW to multi-MW) The modular approach is intended to result in higher-volume, lower-cost, less-loss power electronics building blocks that service many applications, such as DC data center and electric vehicle charge station In this paper, a 225kW, 500 kHz PCSB is demonstrated to direct converter 4160 VAC to 400V DC for a DC date center WBG power devices and CLLC resonant converter are used to minimize switching related loss at high frequency The high frequency transformer of CLLC resonant converter is one of the key elements for the proposed modular approach This paper will focus on high frequency transformer design to realize high-voltage-isolation, high-efficiency and high-density at the same time Based on a split winding transformer structure, transformer insulation material and dimension parameters are determined referring to insulation standard Transformer magnetic loss model is reviewed based on which loss design trade-off is carefully analyzed Finally a 500 kHz transformer prototype has been developed and demonstrated with 30kV isolation capability, whole CLLC resonant converter holds 98% peak efficiency and 48 W/in3 power density

A Novel Transformer Structure for High power, High Frequency converter

Abstract: Power transformer structure is a key factor for the high power, high frequency converter performance which includes efficiency, thermal performance and power density. This paper proposes a novel transformer structure for the kilo-watt level, high frequency converter which is reinforce insulation needed for the secondary side to primary side. The transformer has spiral-wound primary layers using TIW (triple insulation wire) and PCB-winding secondary layers. All the windings are arranged by full interleaving structure to minimize the leakage inductance and eddy current loss. Further more, the secondary rectifiers and filter capacitors are mounted in PCB-winding secondary layers to further minimize the termination effect. A 1.2 KW (O/P: 12 V/100 A, I/P: 400 V) Mega Hz LLC converter prototype employed the proposed transformer structure is constructed, and over 96% efficiency achieved.