The improved features of AC/DC converters, the need to enhance cross-country interconnections, the will to make massive remote renewable energy sources available, and the fear of populations about overhead lines have fostered HVDC cable transmission all over the world, leading in the last two decades to an exponential increase of commissioned HVDC cable projects, particularly of the extruded insulation type. Comprehensive surveys of the issues to be faced by HVDC extruded cable systems appeared in the literature some years ago, but they are not so up-to-date, as HVDC extruded cable technology is developing fast. Therefore, the contribution this paper aims at giving is a systematic, comprehensive and updated summary of the main present and future issues and challenges that HVDC cable systems have to face to further improve their performance and competitiveness, so as to meet the growing quest for clean and available energy worldwide. The topics covered in this review–treated in alphabetical order for the reader’s convenience–are accessories, higher voltage and power, laying environment (submarine and underground cables), modeling, multiterminal HVDC, operation and diagnostics, recyclable insulation, space charge behavior, testing, thermal stability, transient voltages.

Issues and Challenges for HVDC Extruded Cable Systems

A multi-stage active switched inductor-capacitor network (SLCN)-based high gain DC-DC converter structure with a single switch is proposed in this paper. The idea of utilizing multiple number of SLCN networks to achieve an ultra-voltage gain is proposed. The achievement of ultra-gain helps to operate the converter at lower duty ratio. Hence, a reduction of conduction loss, improvement in efficiency and elimination of core saturation are attained in the proposed bi-quadratic converter compared to the conventional converters. The performance of a biquadratic boost converter which is formulated from the <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula>-stage SLCN converter for <inline-formula> <tex-math notation="LaTeX">$n=2$ </tex-math></inline-formula>, is analyzed. To reduce the effect of parasitic elements of the semiconductor devices, the SiC-based devices are selected. The small-signal model of the biquadratic converter is derived, and a PI controller is designed to regulate the output voltage. The designed controller is implemented using XSG platform. Experimental waveforms for 650 V output voltage, 500 W output power and 50 kHz switching frequency are presented. The performance of the proposed converter with similar recently reported topologies is compared. Simulation results of the bi-quadratic converter interfaced solar PV panel with P&#x0026;O algorithm are presented to assess the feasibility of the proposed converter in solar PV application. 

/pdf/switched-lc-network-based-multistage-ultra-gain-dc-dc-25jgln3z.pdf

Switched LC Network-Based Multistage Ultra Gain DC-DC Converter

A multi-stage active switched inductor-capacitor network (SLCN)-based high gain DC-DC converter structure with a single switch is proposed in this paper. The idea of utilizing multiple number of SLCN networks to achieve an ultra-voltage gain is proposed. The achievement of ultra-gain helps to operate the converter at lower duty ratio. Hence, a reduction of conduction loss, improvement in efficiency and elimination of core saturation are attained in the proposed bi-quadratic converter compared to the conventional converters. The performance of a biquadratic boost converter which is formulated from the n-stage SLCN converter for n=2, is analyzed. To reduce the effect of parasitic elements of the semiconductor devices, the SiC-based devices are selected. The small-signal model of the biquadratic converter is derived, and a PI controller is designed to regulate the output voltage. The designed controller is implemented using XSG platform. Experimental waveforms for 650 V output voltage, 500 W output power and 50 kHz switching frequency are presented. The performance of the proposed converter with similar recently reported topologies is compared. Simulation results of the bi-quadratic converter interfaced solar PV panel with P&O algorithm are presented to assess the feasibility of the proposed converter in solar PV application.

https://ieeexplore.ieee.org/ielx7/6287639/9668973/09795285.pdf

Switched LC Network-Based Multi-Stage Ultra Gain DC-DC Converter

A medium voltage (MV) cable network is a substantial component of the distribution network. Present management of this grid segment is mainly based on the failure rate analysis, i.e., a rise in the number and kind of faults on the actual line means that its technical condition is getting worse. The efficiency of the power system is low and additional costs of repair works, supply interruption, difficulties in the investment planning and operation and maintenance works are necessary. The aim of the R&D works done in the realised project is to implement the management of the MV cable network based on the estimated condition of the individual cable line, obtained from diagnostic measurements. The diagnostic investigations of the cable lines are the reference. Many years of research work have led to the development of the Health Index based on diagnostic, technical and service data.

https://www.mdpi.com/1996-1073/14/14/4116/pdf

The Proposal of a New Tool for Condition Assessment of Medium Voltage Power Cable Lines

A newly developed ±550 kV DC GIL (direct current gas-insulated transmission line) prototype was erected at a HVDC test facility at the Technical University of Darmstadt to collect first service experience with this new equipment. The 100 m long DC GIL prototype is periodically stressed with DC voltage and DC current as well as superimposed impulse voltage. The test equipment was procured for the project and partly newly developed. The overall procedure follows the prototype installation test recommendations from CIGRE TB 842. This paper presents experience collected during the commissioning and long-term testing of the DC GIL prototype. The commissioning process, events occurred, as well as resulting conclusions for type, factory acceptance and site acceptance tests of DC GIL systems are discussed. The long-term operation of the DC GIL is intended to run continuously. Interruptions occur due to external influences only. Partial discharge events and the overall performance of the DC GIL prototype during long-term stress are presented. 

Commissioning and Service Experience with a ±550 kV DC GIL conducted in Frame of a CIGRE Prototype Installation Test

This paper deals with an alternative method for monitoring of long and very long HVAC and HVDC cable systems concerning the detection and localization of fatal breakdown errors during routine and commissioning tests as well as under service conditions. The presented principle is based on the Time Domain Reflectometry (TDR) and differs fundamentally from the well-known and established methods. It is applicable to land and submarine cables. The operation of the measuring system should be completely invisible and long-term reliable until the cable system fails. Measurements at installed cable systems have already proved the practical suitability.This paper describes the theoretical concept of the proposed fault location. Necessary measurement systems are described. Furthermore, measurements at installed and stored cables are introduced and evaluated. A special focus is the influence of the high voltage components to the measurement. An automated evaluation procedure is used for the evaluation.The proposed method can be used for a very fast fault location with high accuracy. The required conditions are worked out.

Cable Fault Location in High Voltage Cables – A New Solution

The demand to transport electric energy over large distances increases further. To fulfill this task, the rated DC voltages increased within the last decade. HVDC systems up to 800 kV are in operation and higher transmission voltages are under development. All HVDC equipment, e.g. HVDC valves, transmission lines (air or cables), HVDC transformers, bushings, insulators etc. have to be tested. To perform these development tests, type tests, routine tests and on-site tests, special HVDC and UHDC test systems are needed. This is only realizable with adequate test systems which have to operate at higher voltage levels than the rated voltages of the components to be tested. In doing this, DC test equipment are operating near at the physical and technical limits. This is because DC test equipment does not have to withstand pure DC voltages and currents. In case of a breakdown or flashover of the device under test, the DC test system has to withstand these high transient voltages, often followed by fast polarity changes. Therefore, the electrical field distribution, which mainly is controlled by a resistive field distribution (DC current plus space charges and surface charges), will be overlaid by a (fast) capacitive field distribution, which is in some cases opposite to the resistive field distribution.Area and space restrictions within test fields, the occurrence of fast transients (like in bushings filled with SF6), in combination with surface and space charges lead to very high and complex field stress of the DC test equipment. This implies strong electrical stress on the DC test system and the used materials.This paper will present some examples of special designed DC test equipment. Demanded DC test voltages reach 2000 kV or even more. Thus a realized DC test system with rated voltage of 2000 kV and with a DC current of 100 mA will be described. A concept how to protect the test object and the HV source, like DC-Generator and Impulse Generator used for combined voltage tests, will also be presented.In addition, the need of mobile test systems to perform on-site tests on cables and other HVDC components increases also. Main task here is to handle the field distribution under different environmental conditions and to realize a very compact and robust design. Finally, when testing long DC cables, the safe and reproducible discharging of these long cables is another issue. How to solve this task safe with adequate mobile DC test systems and discharging devices will be presented in this contribution also.

Modular DC Test System

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

R. Pietsch

Author Tools

Chat about Author

Papers

Cable Fault Location in High Voltage Cables – A New Solution

Modular DC Test System