Results 41 to 50 of about 3,260 (186)

Dynamic Behaviour of Bubbles in Oil Under Electrothermal Ageing

High Voltage, EarlyView.
ABSTRACT During long‐term operation of converter transformers, the internal oil–pressboard insulation undergoes irreversible degradation. Partial discharge in the weakened insulation will cause the formation of a large number of bubbles in the insulating oil.
Hongbin Wu, Zhaoyang Kang, Ze Li, Zhongyu Zhao, Shuqi Li, Fuqiang Ren, Hongshun Liu, Qingquan Li   +7 more
wiley   +1 more source

Design and implementation of passive impedance adapter to damp resonances between VSC‐HVDC and AC systems

IET Generation, Transmission & Distribution
It has been known that resonances often occur when high‐voltage direct current (HVDC) systems are connected into the AC system via voltage‐source converters (VSCs).
Changyue Zou, Junjie Feng, Xiaobin Zhao, Yi Yuan, Ting Hou   +4 more
doaj   +1 more source

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

IEEE 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, Yu-Jin Kwak, Bang-Wook Lee   +2 more
doaj   +1 more source

Development of ± 550 kV DC GIS Basin Insulator

High Voltage, EarlyView.
ABSTRACT The basin insulator is a core component of the insulation system for ± 550 kV gas‐insulated switchgear (GIS). This paper, using a finite element method for multi‐physics simulations of electric–thermal coupling, determines a geometry suitable for the industrial production of ± 550 kV GIS basin insulators.
Shaohua Cao, Chengwei Jing, Siqiong Zhang, Zuodong Liang, Zehao Zhang, Fangwei Liang, Yong Yang, Geng Chen, Jinliang He, Chuanyang Li   +9 more
wiley   +1 more source

About the Ageing‐Induced Modifications of Physical‐Chemical and Electrical Properties of Polyimide (PMDA‐ODA) Under Gamma Radiation and High Temperatures

High Voltage, EarlyView.
ABSTRACT This study investigates the effects of radiation‐induced ageing on the physical, chemical, mechanical and electrical properties of Poly[4,4′‐oxydiphenylene‐ pyromellitimide] (PMDA‐ODA) polyimide, a high‐performance insulation material widely used in aerospace applications.
Simone Vincenzo Suraci, Jizhu Jin, Davide Mazza, Davide Fabiani   +3 more
wiley   +1 more source

Comparative Analysis and Optimization of HVAC and Multi-Terminal HVDC Integration 400kV Super Grid (Case Study of Iraq) [PDF]

Problems of the Regional Energetics
The Iraqi 400-kV super grid faces significant operational challenges, including high transmission losses, overloaded transmission lines, voltage instability, and limited long-distance power transfer capability.
Sana Khalid Abdulhassan, Mouna Ben Smida, Anis Sakly   +2 more
doaj   +1 more source

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

2016 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., Davidson, Innocent Ewaen   +1 more
openaire   +2 more sources

Mechanism of Damage and Micro‐Characterisation of Irradiation‐Induced Free Radicals on the Epoxy Insulation of the Bridge Arm Reactors at High Altitude

High Voltage, EarlyView.
ABSTRACT Damage degradation of epoxy resin insulating materials by free radicals triggered by the ultraviolet irradiation environment at high altitude has become a key issue that restricts the reliability of the bridge arm reactor at high altitude.
Liang Zou, Xinya Luo, Zhiyun Han, Zhen Li, Xiaofeng Ding, Kejie Huang   +5 more
wiley   +1 more source

Design and tests of reinforcement-learning-based optimal power flow solution generator

Energy Reports, 2022
Optimal power flow (OPF) is a very traditional problem in the research field of power systems. In this paper, an OPF solution generator based on reinforcement learning (RL) is proposed. The solution process of OPF is modeled as a one-step Markov Decision
Hongyue Zhen, Hefeng Zhai, Weizhe Ma, Ligang Zhao, Yixuan Weng, Yuan Xu, Jun Shi, Xiaofeng He   +7 more
doaj   +1 more source

Deterioration Law of Mechanical Properties of Insulation Pressboard Under Multifield Coupled Ageing

High Voltage, EarlyView.
ABSTRACT Converter transformers can experience progressive deterioration of their oil–pressboard insulation under elevated temperature, combined AC–DC electrical stress and persistent mechanical vibration. This study investigates how mechanical vibration affects the mechanical properties of insulation pressboard and clarifies the associated microscopic
Jiayi Chen, Guan Wang, Zihao Li, Zhongyu Zhao, Kuo Yan, Hongshun Liu   +5 more
wiley   +1 more source