Ein supraleitender Strombegrenzer für die Energieübertragung

2011-05-09 © Siemens AG, Corporate TechnologyW. Schmidt, CT T DE HW 4

Ein

supraleitender

Strombegrenzer für

die Energieübertragung

6. Braunschweiger

Supraleiterseminar11. -

12. Mai 2011

Wolfgang Schmidt, Hans-Peter Krämer Siemens AG, Corporate Technology

Erlangen


The Project and the Team

Development and InDevelopment and In--Grid Demonstration of a Transmission Grid Demonstration of a Transmission Voltage Voltage SuperLimiterSuperLimiterTMTM

Fault Current LimiterFault Current Limiter

funded by the U.S. Department of Energy funded by the U.S. Department of Energy --

National Energy National Energy Technology LaboratoryTechnology Laboratory

American Superconductor Corporation: A. Otto, E. Podtburg, J. Maguire, J. Yuan, P. Winn, W. Romanosky, B. Gamble, D. Madura.

M. Ross, D. Folts,

H. Cai, J. McNamara, T. MacDonald and A. P. Malozemoff,Siemens AG Corporate Technology:

H.-P. Kraemer, P. La Seta, W. Schmidt, M. Wohlfart, and H.-W. Neumueller,

Nexans: N. Lallouet

and F. Schmidt. Los Alamos National Laboratory:

S. Ashworth and J.O. Willis.Southern California Edison:

S. Ahmed.


Outline

Introduction Needs

for

fault current

limitation

in power grids Recently

pursued

concepts

of fault current

limiters

Basics of the

resistive superconducting

fault current

limiters

(SFCL) Functional principle

Basic dimensioning

rules Basic design

of switching

elements

History

of SFCL at Siemens

Current

project: High voltage

SFCL (115 kV / 1.2 kA) funded

by

DOE Project overview: partners, schedule, specifications, status

Test sites

analyzed Design of module

and switching

elements

Manufacture

and testing

of the

first

phase

Summary

and Outlook


The Need for Current Limiting Devices in Power Grids

“The most important near term energy and utility markets appear to be fault current limiters

and synchronous condensers.”

High Temperature Superconductors (HTS) Peer Presentation Document –

July 25, 2006 Navigant Consulting, Inc.

Citation from Navigant Consulting (2006):"Increasing loads on the existing power transmission system, coupled with lack of investment, lead to a growing demand for current limiting devices.

The perfect fault current limiting device features an instantaneous, self triggered transition from near zero impedance to above grid impedance in case of a fault.

→ Superconducting Fault Current Limiters (SFCL) can provide the solution. "


Need for Fault Current Limitation

The fault current levels rise due toincreasing power consumption interconnection of grids to improve reliability and voltage stability

additional feeding by IPPsConventional solutions

reactors pyroelectric

limiters

no limitation, but switching off by breakers, while designing all components to carry the full fault current until the breaker opens

however, fault currents are often close to or even higher than rated breaking current of installed breakers

Wish for a current limiting device, which is …self-acting, self-restoring, fail-safe, compact, inexpensiveThe resistive HTS-FCL can meet most of these requirementsefficient use of existing grids at increased load

components with reduced ratings in new grids


Recent Concepts of Fault Current Limiters

Limitation by a variable inductance1.

Non-superconducting:

Short circuit current limiter SCCL. Series L-C circuit, resonance at 50/60Hz

thyristors shorten out the capacitor bank. Siemens (Germany)

2.

Superconducting (no quench): Saturated iron core limiter.

Two coils, iron yokes normally saturated by a HTS-DC-coil, fault drives the core out of saturation. Innopower (China), Zenergy (USA), GridOn

(Israel)


Recent Concepts of Fault Current Limiters

Limitation by a variable resistance1.

Non-superconducting:

Is-limiter. Conductor bridge enclosing an explosive charge. Fuse in parallel.

ABB (Germany), G&W (USA)

2.

Superconducting (quench): Resistive & inductive limiter (SFCL).

Immediate "quench" triggered by current surges.

Nexans, Siemens, Bruker

(Germany), SuperPower, AMSC (USA), Hyundai, LS Industrial Systems (Korea)


I

Bulk BSCCOcylinders (Nexans)

Thick BSCCO layers (ABB until 2001)

YBCO tapes (Siemens, Toshiba, SuperPower, AMSC, Hyundai, and LSIS after 2003)

Liquid NitrogenCryostat

Current Leads (Copper)

HTS-materials:

Fast breaker

Variable resistance with mandatory fast circuit breaker in series.

Refrigerator

SFCL -

The Pure Resistive Principle


0 25 50 75 100 125 150 175

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

Temperature: 77.5 K 76.1 K 74.9 K 73.1 K 72.2 K 70.5 K 69.2 K

U [m

V]

I [A]

Functional Principal of Resistive SFCL

Very

sharp

current

–

voltage

characteristic

of YBCO thin

filmsvery low R in normal operation, high dR/dI above Icvery fast 'switching' to the resistive state when thecritical current is exceededself-actingvery effective currentlimitationself-restoring afterfault current interruption

But, warming

up during

limitation:fast switch-off after a fault is mandatorywait for recoverybefore re-activation


System parameters

Total length

Material parameters

max. voltage

U

at SFCL

maximum

temperature

Tmax

max. fault holding

time Δt:

normal cond. resistivity

ρ(T)specific

heat

c(T)

of the

compoundTotal cross sectionof superconductor

maximum

current

critical

current

density

jc

during

normal operation

Îmax

at operating

temperature

Basic Dimensioning Rules

dTTcT

tUL T

Tc∫ ⋅

Δ=

max

)()(ρ

cjIA maxˆ

=

Selection

of operating

temperature

...trade-off

between

conductor and cooling

cost


-

+

Modular Concept Based on Switching Elements

Design issues

of basic

"switching

elements" (coils):

Requirements

Solutioncompactness

pancake

coil

low

inductance

bifilar

windingfast recovery

spacer

for

LN2

transparency

spacer

2G HTS wire

Alternating

current

directions

in adjacent

turns

reduce

the

magnetic

field:low

inductance, low

AC loss

Modular setup

by

serial

and parallel connection

of "switching

elements"


History of SFCL Devolopment

at Siemens

100 kVA

model using sapphire

switching elements1.2 MVA; 7.2 kV

2 MVA / 7.2 kV

0.9 MW; 900 V-DC

YBCO on YSZ ceramics

with IBAD buffer

YBCO on metal tape from AMSC100 x 200 mm

YBCO on sapphire

4''-substrate

YBCO on sapphire

BMBF-Funding: Material development & functional models Co-operation with AMSC

DOE project with AMSC

Jan 2002

Supported by PTD M C

3.6 MVA / 8.4 kV

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

42 MVA / 31 kV


Transmission Voltage SFCL Overview of Current DOE Funded Project

Phase 1a: Core Technology DevelopmentPhase 1b: HV single phase 115 kV ; 1.2 kA

Phase 2: HV three phase program 115 kV ; 1.2 kAIn-grid installation and testing

2008 2009 2010 2011 2012

Goal:•

Development and in-grid testing of a three phase high voltage 115kV (138kV class) Fault Current Limiter, based on High Temperature Superconductors

•

Funded by US DOE. Overall budget $ 25.4 million for 4.5 years. 50% cost share. Siemens budget $ 4.3 million.

•

Partners AMSC, Siemens, Nexans, LANL, SCE, TCSUH.

Superconductor module: SiemensCryostat and wire : AMSCTerminations: NEXANS

PLAN:


SStatus of the DOE Funded Project

•

Planned installation site: Outgoing line at Devers substation.

•

First electrical phase completed and shipped at end of fiscal year 2010.

•

Power test finished Feb 2011, final high voltage test scheduled for June 2011.

Individual vessels for each phase

Reactors

Terminations and surge arrestors

Dead tank circuit breakers


Refrigeration System

Power Heat

FCL Vessel

Protection and DAQ System

Reactor

Sized to Limiting Requirements

Opening SwitchSource

Load

SwitchControl

Assembly

Required site limited current is adjusted by using an external reactor. Voltage across a shunted limiter

is significantly reduced for low fault

current reduction: 115 kV /

√3 = 66 kV reduces to 31

kV

Nominal Voltage 115 kVrms

Insulation Class 138 kV

Nominal Current 1,200 Arms

Maximum Site Unlimited Fault Current 63 kArms

Required Site Limited Current 40 kArms

Trip Current 1.6 ×

nominal current

Original Specifications of the Transmission Voltage SFCL

Sub-cooled

LN2

at ~72 …

74 K, 5 bar


Proposed Test Sites for the Transmission Voltage SFCL

Two test sites in Southern California Edison's grid have been analyzed using time domain grid planning tools.

Valley Substation Devers Substation

Located near Riverside, CA in a desert climate

Located very near Palm Springs, CA in a desert climate

115 kV bus tie application 115 kV line application

SFCL provides an 18% reduction in fault current at one of the tied buses

SFCL provides a 33% reduction of fault current on the out-going line

The design voltage of 30.7 kV across the SFCL module had to be fixed before finalization of grid integration studies. Therefore, the impedance of the parallel reactor was adjusted to the grid impedance. This causes the site dependent fault current reduction.


Valley Substation at Southern California Edison

Bus TieBus Tie

115 KV 115 KV Outgoing Outgoing FeederFeeder1000 MW 1000 MW

Future GenFuture Gen

Inland EmpireInland Empire

115 kV115 kV

115 kV115 kV

500 kV500 kV

115 kV115 kV

““AA”” ““BB””

““CC”” ““ABAB””

SerranoSerrano

500 kV500 kV

Devers Devers 500 kV500 kV

(Studied)(Studied) (Selected)(Selected)

Present Installation:•

4 Transformers 560 MVA; 525/120 kV

•

Sectionalized 115 kV bus;

each section fed by 2 transformers

•

Max. single-phase-to-ground fault current: 30 kA

•

All 115 kV circuit breakes

rated 40 kA

Planned Future Installation:•

Load growth in the area and interconnection of new generators will require additional transformers

•

Fault current duty will rise above 40 kA

For SCE, current

limiters

are

the

preferred

alternative against

upgrading

substations.Evaluation of current

limiters

requires

operation

in a grid

for

more

than

one

year.


Bifilar coils, the basic switching elements, are arranged as horizontal stack Support legs are resting on the cryostat inside wallCorona rings and end plates are attached for electric field controlComplete module for one electrical phase has been assembled

Modular concept allows simple, expandable, and robust mechanical

designs

Mechanical Design of Switching Module

0.6m dia.


79 bifilar coils have been wound and tested, 63 coils have been selected for the moduleThorough testing has been applied to each coil: R(295K), Ic, 32 switching tests,..

Coil design characteristics•Bifilar winding

for low inductance and low AC loss•two-in-hand winding and 1.2 cm wide tape

for higher compactness•back-to-back tape orientation

for reduced AC loss•spacer tape between winding turns

for high LN2

transparency•wire insulation

for increased electrical strength

Basic module design provides ultra low line impedance in normal operation

Bifilar coils


-4

-2

0

2

4

-10 0 10 20 30 40 50 60 700

20406080

100120

-4

-2

0

2

4

Current ICur

rent

(kA

)

time (ms)

Res

ista

nce

ratio

(%)

Single coil, Ic @ 77 K = 530 A, R295K = 1.53 Ω

Voltage V

Vol

tage

(kV)

Voltage and current recorded over time, resistance calculated

Variation of: Voltage, fault hold time, phase

angle

Measured parameters: Peak current, limited current,

resistance ratio at fault hold time (maximum temperature)

→ Rmax

/R295

is the key figure indicating the load applied to a coil

Maximum load coils are subjected to under nominal condition is Rmax

/R295

= 106 % (~350 K)

Rmax

/R295K

Peak current

Limited

current

Standard switching

tests insure

coils

meet

performance requirements

Details of Switching Tests


Stainless Steel Stabilized 2G Wire Provided by AMSC

Insert wire:

Laminated wire: 12 mm total width

thic

knes

s:0.

28 m

m

Stainless steel stabilizer (75 µm) soldered to the insert wire

Stainless steel laminates enable RABiTS

conductors for FCL applications: Increased resistivity and superior mechanical and electrical stability Critical current Ic

= 253 A average (300 A planned) @ 77 KResistance R(295 K) / length = 114 mOhm/m

average

Rated voltage U

/ length = 54.6 Vrms

/m

at 67 ms fault hold time

75 µm

0.8 µm

4 cm tape process:


Lightning Impulse Test of the Subscale Module

A subscale switching module has been equipped with corona rings and end plates for conducting lightning impulse voltage withstand measurements at the University of Braunschweig.

No breakdown at 220 kV in air at 1 bar (15 pulses with both polarities).Specification of 650 kV in nitrogen at 5 bar can be met (by scaling plus margin).


All tests completed without breakdown:200 kV AC 60 Hz withstand for 15 minutes.650 kV lightning impulse 15 times in each polarity.

HV connection

½

inch diameter threaded rod

4 inch diameter tube

Dummy corona ring

Support leg

42 inch fiberglass tub

Rail on grounded plate

High Voltage Tests of a Radial Support Leg

Testing in liquid nitrogen at atmospheric pressure . Oak Ridge National Lab, July 9th, 2009 (R. James, R. Ellis, D. Madura)

Dis

tanc

e m

odul

eto

ve

ssel

insi

dew

all


Basic mechanical data:3 coils in parallel21 triplets in series

63 coils in totalLength: 5 mDiameter: 0.6 m

Basic electrical data:Design voltage: 30 kVrms

Critical current: 1900 A @ 74 KRated current: 900 Arms (trip factor 1.5)Module apparent power: 42 MVA

∅

535

350

Assembly of the Single Phase Switching Module


Comissioning

of Module, Cryostat and Terminations at Powertech

Laboratories (Nov. 2010, Surrey, B.C)


Setup for the Single Phase Power Tests (Feb. 2011)

1: FCL, 2: LN1: FCL, 2: LN

22

refillrefill

tank, 3: tank, 3: bushingsbushings, , 4: 4: busbarsbusbars, 5: , 5: voltagevoltage

transducertransducer

Sequence of power tests:Increase voltage to rated valueVary fault phase angle

at various prospective currents

Determine recovery timeDemonstrate limitation of

2 faults within 1 minute20 power test at U > 28 kVrms


Comparison with unlimited current

Uo

= 30 kVIprosp

= 20 kArms

Δtfault

= 58 msIpeak

= 9.3 kAIlim

= 2.6 kArms

Power Tests Results

-20 0 20 40 60

-20

-10

0

10

20

30

40

50

60

-40

-20

0

20

40

60

80

100

120

t (ms)

I FCL (

kA),

I pros

p (kA

)

U (k

V)


Determination of recovery time

Uo

= 28 kVIprosp

= 20 kArms

Δtfault

= 63 msΔtrec

= 25 s

Power Tests Results

-8

-4

0

4

8

12

-4

-2

0

2

4

6

-40

-20

0

20

40

-40

-20

0

20

40

0.00 0.050

20406080

100

24.95 25.00 25.05 25.100.00.10.20.30.40.5

I (k

A)

I (k

A)

1.5 kA

U (k

V)

U (V

)

R/R

295K

(%)

t (s)

R/R

295K

(%)


Two consecutive faults within 62 s time interval

Uo

= 28 kVIprosp

= 20 kArms

Δtfault

= 58 ms

Power Tests Results

-8

-4

0

4

8

-8

-4

0

4

8

-40

-20

0

20

40

-40

-20

0

20

40

-0.05 0.00 0.05

020406080

100

61.55 61.60 61.65

020406080100

I (k

A)

U (k

V)

R/R

295K

(%)

t (s)


Setup for the High Voltage Insulation Tests

Partial discharge test (at 114 kVrms

) and power frequency voltage test (15 min at 190 kVrms

):Successfully finished Feb. 2011

Lightning impulse test (650 kVpeak

):Scheduled for June 2011


Conclusion and Outlook

Project phase 1a successfully finishedDesign of bifilar coils as switching elements under HV aspectsSubscale module made of 6 full size coils fabricated

and successfully tested at IPH Berlin, 8.4 kV ×

425 A = 3.5 MVA

Project phase 1b mostly finished:One complete phase of the FCL manufacturedRated apparent power: 30.9 kV ×

1.35 kA = 42 MVA (74 K)

Power tests at PowerTech

labs. (Surrrey) passed successfullyHigh voltage tests to be repeated in June 2011

Phase 2 canceled by DOE due to shift in funding

Ein supraleitender Strombegrenzer für die Energieübertragung

Documents

Transcript of Ein supraleitender Strombegrenzer für die Energieübertragung