Isolation transformer

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

Method of feedback regulating a flyback power converter

Abstract: A method of providing power regulation in power conversion equipment, where power regulation is implemented on the primary side of a transformer used to provide isolation of a power source from the load. The feedback mechanism utilizes current perturbations which are summed with the primary current in the power transformer. These perturbations are transformed with the load current to the primary side of the power transformer and extracted using signal processing means to regenerate a useful signal which is isolated from the load.

Harmonics from SVC transformer saturation with direct current offset

Abstract: Circulation of direct current in transformer windings can cause significant transformer saturation and harmonic generation. This problem may be experienced by static VAr compensators with an anti-parallel thyristor arrangement. This paper presents a technique to analyze the harmonic distortions caused by transformer saturation with direct current offset. The technique is used to investigate the harmonic generation from the transformer of a static VAr compensator to be installed in the BC Hydro system. >

A novel PCB winding transformer with controllable leakage integration for a 6.6kW 500kHz high efficiency high density bi-directional on-board charger

Abstract: Printed Circuit Board (PCB) transformer has been widely used in low power applications. Compared with conventional litz-wire transformer, the manufacture process is greatly simplified and the parasitic is much easier to control. However, in high power applications like on-board charger for electric vehicle, no one has ever done it due to the limitation of high winding loss and high multi-layer PCB cost. The emerging wide-band-gap devices provide the opportunity to adopt PCB transformer in high power applications. In addition, the low inductance requirement brought by high frequency also makes it possible to realize magnetic integration in PCB transformer. In this paper, by using a two stage variable DC-link voltage structure, a novel 6-layer only PCB winding transformer structure is proposed for the second stage of the 6.6kW on-board charger, of which leakage inductance is controllable without sacrificing winding loss. A 6.6kW 500kHz prototype with almost 98% efficiency and 130W/in3 power density is built to verify the feasibility of the proposed PCB winding transformer.

Multiphase Quasi-Z-Source DC–DC Converters for Residential Distributed Generation Systems

Abstract: A multiphase quasi-Z-source (qZS) dc–dc converter was proposed for distributed energy generation applications It contains single-switch qZS isolated dc–dc cells with a voltage doubler rectifier These cells are connected in parallel at the input side and in series at the output side to increase the dc voltage gain A dc voltage blocking capacitor in series with the isolation transformer results in resonance that could be utilized for soft-switching Two design approaches were proposed: considering phase shedding dependent on the input voltage and without it The former targets wide input voltage range applications, while the latter is better suited for high input current applications An experimental prototype rated for 300 W was tested with two types of isolation transformers designed according to the two presented approaches It could be used as a PV module integrated converter with wide input voltage regulation range The experimental results prove efficiency improvement from the phase shedding Resonance frequency variations caused by the utilization of the multilayer ceramic capacitors and their possible influence on switching losses are discussed

DC to DC Converters

Abstract: The linear power supply is a mature technology, having been used since the dawn of electronics. However, due to its low efficiency, the use of bulky heat sinks, cooling fans, and isolation transformers, this type of power supply tends to be unfit for most of today's compact electronic systems. The disadvantages of linear power supplies are greatly reduced by the regulated switching power supply. In this technology, the AC line voltage is directly rectified and filtered to produce a raw high-voltage DC. This, in turn, is fed into a switching element that operates at a high frequency of 20 kHz to 1 MHz, chopping the DC voltage into a square wave. This high-frequency square wave is fed into the power isolation transformer, stepped down to a predetermined value and then rectified and filtered to produce the required DC output. This chapter examines DC to DC conversion process, which is at the heart of switching power supplies.