Results 51 to 60 of about 17,685 (234)

Field Studies on the Influence of High‐Voltage Direct Transmission Underground Cables on Soils Along the SuedLink Route in Southwest Germany

open access: yesJournal of Plant Nutrition and Soil Science, EarlyView.
During regular operation of the SuedLink at a load ≤75 %, the average increase in temperature in the plowing horizon is expected to be less than 1.6°C in the soils along the route in Southwest Germany. ABSTRACT Background The SuedLink was planned as a high‐voltage direct‐current underground cable route. The construction itself is a massive intervention
Joachim Ingwersen   +10 more
wiley   +1 more source

The electromagnetic transient simulation acceleration algorithm based on delay mitigation of dynamic critical paths

open access: yesEnergy Informatics
The task scheduling problem based on directed acyclic graphs (DAGs) has been proven to be NP-complete in general cases or under certain restrictions.
Qi Guo   +7 more
doaj   +1 more source

Valve-Side Single-Phase-to-Ground Fault Clearance in Bipolar Hybrid-MMC HVDC Systems Utilizing Thyristor Commutation Branches and Mechanical Interrupter

open access: yesIEEE Access
The Hybrid Modular Multilevel Converter (HMMC) topology—comprising full-bridge (FB) and half-bridge (HB) submodules—is effective for DC fault clearance in HVDC systems.
Muhammad Usman, Il Kwon, Bang-Wook Lee
doaj   +1 more source

HVDC Circuit Breakers–A Review [PDF]

open access: yesIEEE Access, 2020
HVDC circuit breakers are of increasing importance, as multi-terminal high voltage DC (HVDC) transmission becomes a commercial reality. Multiple HVDC breaker technologies have been developed, and are starting to appear as proof-of-concept installations on real networks. Information about them is however distributed widely in the literature.
Mike Barnes   +5 more
openaire   +1 more source

Micro Partial Discharge Characteristics of SF6 Under DC Voltage

open access: yesHigh Voltage, EarlyView.
ABSTRACT In gas‐insulated high‐voltage direct current (HVDC) devices, micro partial discharges (PD) caused by micro‐protrusions or surface roughness on conductors or enclosures may not cause immediate insulation system failure due to their weak discharge intensity.
Geng Chen   +4 more
wiley   +1 more source

Fault Current Limiter and Mechanical DC CB-Based Protection Against Valve-Side SPG Faults in HB-MMC Bipolar System

open access: yesIEEE Access
Valve-side single-phase-to-ground (SPG) faults are atypical yet critical for the operation of half-bridge (HB) Modular Multilevel converter (MMC) bipolar or asymmetrical monopolar systems.
Muhammad Usman   +2 more
doaj   +1 more source

Research on coordinated reactive power control strategy of hybrid-HVDC

open access: yesThe Journal of Engineering, 2019
Based on the hybrid HVDC transmission system, which is composed by line-commutated converter (LCC) in parallel with voltage source converter (VSC), a coordinated reactive power control strategy of hybrid-HVDC in both steady and transient states is ...
Ying Huang, Chunhua Li, Tao Liu
doaj   +1 more source

Construction and Application of Online Vibration Frequency Response Analysis Method for Converter Transformer Winding

open access: yesHigh Voltage, EarlyView.
ABSTRACT The harmonic current and vibration of a converter transformer are effective pieces of information for detecting mechanical faults in the winding. In this paper, the ratio of vibration acceleration to the current squared is defined as the vibration frequency response function (VFRF) of the winding, and then, a novel online vibration frequency ...
Shuyu Wu, Fan Zhang, Shengchang Ji
wiley   +1 more source

The effect of Transient over Voltages on the Partial Discharges activity in HVDC joints

open access: yes, 2021
Rapid growth of HVDC cable line installations is expected in the coming years. Several research groups have investigated dielectric phenomena that occur in the insulation of HVDC cables and accessories that accelerate aging and reduce the reliability of ...
Romano P.   +6 more
core   +1 more source

Harmonie distortion of LCC-HVDC and VSC-HVDC link in eskom's cahora bassa HVDC scheme

open access: yes2016 IEEE International Conference on Renewable Energy Research and Applications (ICRERA), 2016
Cahora Bassa, a thyristors based HVDC link transmits 1,920 MW of power from hydropower plant located in Zambezi river, north of Mozambique to Johannesburg, South Africa. This HVDC converter suffer few deficiency in its high level of harmonics distortion that transferred into its AC side of the transmission network couple with persistence rate of ...
Oni, Oluwafemi E.   +1 more
openaire   +2 more sources

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