Growing Demand for Testing DC Cables & Accessories: Experience - - PowerPoint PPT Presentation

Growing Demand for Testing DC Cables & Accessories: Experience & Special New Requirements

HEIKO JAHN

GROWING DEMAND FOR TESTING DC CABLES AND ACCESSORIES: EXPERIENCE AND SPECIAL NEW REQUIREMENTS

Heiko ¡Jahn ¡and ¡Uberto ¡Vercello3 ¡ CESI ¡Group ¡-­‑ ¡Tes>ng ¡& ¡Cer>fica>on ¡Division ¡ Mannheim ¡(Germany) ¡and ¡Milano ¡(Italy) ¡

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2015 INMR World Congress, October 18-21, 2015

Welcome

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2015 INMR World Congress, October 18-21, 2015

• 1. Introduction
• 2. Cable Tests
• 3. Test Set-Up and Experiences
• 4. Summary and Conclusions

Content

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2015 INMR World Congress, October 18-21, 2015

Introduction

Why does the need for HVDC transmissions increase? HVDC transmission

• does not need compensation of reactive power, therefore costs for

losses decrease, especially for cable transmission

• can couple parts of the grids which are not synchronous
• has no skin effect, no eddy currents
• reduces the number of conductors for transmission

HVDC transmission provides advantages from technical, economic but also from environmental point of view

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2015 INMR World Congress, October 18-21, 2015

Introduction

Grid Connection Project Rated Power [MW] Status Scheduled Start of Operation alpha ventus NOR-2-1 60 Operation 2010 BorWin 1 NOR-6-1 400 Operation 2010 Baltic 1 OST-3-1 50 Operation 2011 Riffgat NOR-0-1 110 Operation 2014 HelWin 1 NOR-4-1 580 Operation 2014 SylWin 1 NOR-5-1 860 Test run 2015 BorWin 2 NOR-6-2 800 Test run 2015 Baltic 2 OST-3-2 340 Preparation/Building phase 2014 DolWin 1 NOR-2-2 800 Preparation/Building phase 2015 DolWin 2 NOR-3-1 920 Preparation/Building phase 2015 HelWin 2 NOR-4-2 690 Preparation/Building phase 2015 Nordergründe NOR-0-2 110 Preparation/Building phase 2016 DolWin 3 NOR-2-3 900 Preparation/Building phase 2017 Ostwind 1 OST-1-1 250 Preparation/Building phase 2017 Ostwind 2 OST-1-2 250 Preparation/Building phase 2018 Ostwind 3 OST-1-3 250 Preparation/Building phase 2018 BorWin 3 NOR-8-1 900 Preparation/Building phase 2019

Example: Grid connections for offshore wind energy in Germany

Source: ¡Wind ¡energy ¡report ¡ Germany ¡2014, ¡Fraunhofer ¡ Ins>tute ¡for ¡Wind ¡Energy ¡and ¡ ¡ Energy ¡System ¡Technology ¡ ¡ IWES, ¡2015 ¡

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

HVDC Cable technology and testing standards (1)

20 ¡µm ¡

“Classic” technology

• Paper-insulated cables
• Oil-filled paper insulated cables
• Mass-impregnated cables
• Internal gas pressure cables

“State-of-the-art” technology

• Extruded cables

The development of the cables technology is reflected in the development of testing recommendations

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

HVDC Cable technology and testing standards (2)

20 ¡µm ¡

CIGRÉ recommendations

• CIGRÉ WG 21.02: Recommendations for tests of power transmission DC cables for a rated

voltage up to 800 kV. ELECTRA No. 189, pp. 39-55, April 2000

• CIGRÉ Report 219 by WG 21.01: Recommendations for testing DC extruded cable systems

for power transmission at a rated voltage up to 250 kV, February 2003

• CIGRÉ Report 496 by WG B1.32: Recommendations for testing DC extruded cable

systems for power transmission at a rated voltage up to 500 kV, April 2012

IEC standard (under preparation)

• IEC 62895 “HVDC power transmission cables with extruded insulation and their

accessories for rated voltages up to 320 kV for land applications – Test methods and requirements”

Client’s specification (example)

• TERNA Technical Specification CSI CV ST 1401 “Polarity reversal tests on a 350 kV DC

extruded cable system following TERNA procedures - rev. 1 06/2014”

The compliance with the requirements has to be tested, of course

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

HVDC Cable technology and testing standards (3)

20 ¡µm ¡

Accredited laboratories increase the credibility of the test results, a list can be found on: http://www.inmrlaboratoryguide.com/

Development Tests Performed in the development phase of the cable system Manufacturer Routine Tests Performed on each manufactured component to check that the component meets the specified requirements Manufacturer Type Tests Performed in order to prove satisfactory performance characteristics to meet the intended application, carried out before supplying a cable system Accredited laboratories Long Duration/Pre- Qualification Tests Performed to demonstrate reliability of the complete cable system based

• n long-term performance

Accredited laboratories After-Installation Tests/On-Site Tests Performed in order to demonstrate the integrity of the cable system as installed Manufacturer/ Accredited suppliers

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

HVDC Cable technology and testing standards (4)

20 ¡µm ¡

Test programme is different and depends on converter technology, LCC tests are valid for VSC tests, but not vice versa

CIGRÉ ¡Report ¡496 ¡by ¡ WG ¡B1.32: ¡ Recommenda>ons ¡for ¡ tes>ng ¡DC ¡extruded ¡ cable ¡systems ¡for ¡ power ¡transmission ¡at ¡ a ¡rated ¡voltage ¡up ¡to ¡ 500 ¡kV, ¡April ¡2012 ¡

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

The new CESI HVDC cable testing facility in Mannheim/Germany (1)

20 ¡µm ¡

Build-up for but not limited to the test of extruded HVDC cables Features

• Size: 60 x 26 x 21 m (LxWxH)
• 3 independent areas (26 x 20 m each)
• 3 HVDC generators 800 kV, 1200 kV and

1600 kV

• Impulse generator 3000 kV/300 kJ
• Direct access to 6000 m² outdoor test area

to extend loops

• MV cable connection to the high-power

laboratory

• Shielding better 1 pC

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2015 INMR World Congress, October 18-21, 2015

Cable Tests

The new CESI HVDC cable testing facility in Mannheim/Germany (2)

20 ¡µm ¡

Build-up for but not limited to the test of extruded HVDC cables Capabilities:

• Tests on extruded HVDC cables according

to recent CIGRÉ recommendation

• General dielectric tests on cables,

insulators and other equipment

• Long-term tests on thyristor valve modules
• Tests according to client’s specification

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2015 INMR World Congress, October 18-21, 2015

Test Set-Up and Experiences

Physical set-up

• General layout as for AC cables, i.e. a loop including cable, terminations and accessories
• Heating is done with AC current induced into the short-circuited loop
• Measurement of conductor temperature is the same as for AC cables, i.e. with thermal

image loop

• Cable specification may require heating of the cable sheath to decrease the temperature

difference between conductor and sheath

Care has to be taken

• For EMC of the test equipment in case of a dielectric breakdown
• For electrostatic charge of all parts in laboratory which are not solidly grounded

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2015 INMR World Congress, October 18-21, 2015

Test Set-Up and Experiences

Example curve for a load current test cycle

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2015 INMR World Congress, October 18-21, 2015

1. The tests are still going on. The aim is to gather information about the current state of the art in extruded HVDC cables under polarity reversal stress. 2. This research program has been undertaken by TERNA/Italy in order to increase the knowledge of innovative materials and components for HVDC cable systems. The collected information is a benefit for cable suppliers but also TSOs that will be the end users of such technology. 3. The availability of a Third Party laboratory represents a fundamental step forward in the HVDC cable system market, where extruded cable systems have gained fast increasing shares during the last decade.

Summary and Conclusion

Milan ¡ Berlin ¡ Mannheim ¡ Dubai ¡ Rio ¡de ¡Janeiro

Testing • Consulting • Engineering • Environment

www.cesi.it