The complicated hybrid ac-dc network architecture creates new challenge for electromagnetic transient (EMT) simulation of large-scale systems in terms accuracy and efficiency. By utilizing the variable time-stepping (VTS) method graphics processing unit (GPU) parallelism, this article proposes a four-level dynamic parallelism EMT grids. applying proposed hierarchical system decomposition VTS sc...

A diode rectifier-modular multilevel converter AC/DC hub (DR-MMC Hub) is proposed to integrate offshore wind power the onshore DC network and production platforms (e.g., oil/gas hydrogen plants) with different voltage levels. The DR MMCs are connected in parallel at AC collection power, series terminals of platform network. Compared conventional parallel-connected DR-MMC HVDC systems, reduces r...

Direct current transformer (DCT) is a key piece of equipment in direct (DC) microgrids, and the mainstream topologies mainly include LLC resonant converter (LLC) dual active bridge (DAB). In this paper, novel bi-directional buck/boost + CLLLC cascade topology proposed for input-series-output-parallel system DC microgrid. To solve problem that frequency variation causes to deviate from optimal o...

DC/DC boost converters are usually used to interface the DC output of modern distributed generation resources with the AC system. Distributed generation modules are aggregated to yield the necessary power using either parallel or cascaded architecture. Detailed modeling of an interconnection system incorporating cascaded architecture has not been considered in previous researches. In this paper...

Low-energy characteristic X-ray emission is detected during bombardment of positive low energy ions onto insulator materials. The phenomenon is considered to be related to surface charge-up. To study further the mechanism, the characteristic X-rays was studied during 30 keV Gaþ ions bombardment onto Al2O3 monocrystalline specimens applied with a direct current (DC) bias in the present work. The...

The spin current pumped by a precessing ferromagnet into an adjacent normal metal has a constant polarization component parallel to the precession axis and a rotating one normal to the magnetization. The former is now routinely detected as a dc voltage induced by the inverse spin Hall effect (ISHE). Here we compute ac ISHE voltages much larger than the dc signals for various material combinatio...

In this paper the parallel connection of two three-phase buck-type unity power factor rectifier systems is investigated experimentally for a 10kW DSP-controlled prototype. There, a space vector modulation scheme is employed which shows all advantages of interleaved operation of the two systems. Three control schemes for active DC-side current balancing are described. The control schemes do diff...

A novel method of parallel switching power with different capacity in a controllable current sharing method is presented in this paper. It achieves proportional current sharing and stable output DC voltage by using controllable current sharing modes which output assignable feedback signals to the paralleling buck DC-DC converters. The validity and effectiveness are verified through comprehensiv...

Energy Recovery Battery Testing Systems (ERBTS) plays an important role in battery manufacture. The conventional ERBTS configuration contains a fundamental transformer, and a bidirectional Direct Current (DC)–DC and Alternating Current (AC)–DC converter. All ERBTS are connected in parallel, thus constituting a special and complicated AC micro-grid system. Aiming at addressing their low energy r...