Family of single‐phase high‐frequency isolated AC–AC converters

Abstract

This work presents a family of single‐phase ac–ac converters with high‐frequency isolation based on the association of interleaved transformers and the dual active bridge (DAB) converter. From distinct configurations of the dc link in terms of half‐bridge (HB), full‐bridge (FB), and interleaved full‐bridge (IFB) arrangements, one can obtain three symmetrical and six asymmetrical structures, with distinct trade‐offs among the number of active switches, total dc‐link voltage, and effective operating frequency of the filter elements. Prominent advantages of the derived circuits include input power factor correction (PFC), a nearly sinusoidal load voltage, the operation of active switches under soft‐switching condition during part of the line period, reduced current stresses, good current sharing due to the interleaved transformers, as well as multilevel voltage waveforms on both sides of the high‐frequency transformer (HFT). Experimental results obtained from an experimental prototype of an ac–ac FB‐IFB converter are presented to validate the theoretical assumptions.

Phase shift control of dual active bridge DC‐DC converter based on feedforward compensation and transient optimization strategy

“…It can be seen from Figure 4B that after the transient time, the positive falling edge of v h1 changes from the original positive falling edge lagging behind v h2 to the positive falling edge ahead of v h2 . The expression of φ p and φ s when the power changes from negative to positive, (5), can be obtained.…”

“…Moreover, the integration of a bidirectional DC‐DC converter is imperative between the energy storage unit and the DC bus, serving as a crucial controller for energy exchange. In many applications, there is a requirement for bidirectional flow of energy, for example, energy storage systems, 1 uninterruptible power supplies, 2 photovoltaic (PV) modules, 3 power electronic traction transformers, 4 Solid State Transformers 5,6 and DC transformers (DCT).…”

A novel bridgeless flying capacitor multilevel rectifier

“…The multilevel converter has been widely used in the fields of high‐voltage high‐power adjustable speed motor drives, active power filter (APF), high voltage direct current transmission (HVDC), and reactive power compensation 1,2 . The most typical multilevel converters are neutral point clamped (NPC), 3,4 cascaded H‐bridge (CHB), 5 and flying capacitor (FC) 6 .…”