Información clave en la especificación de Filtros · the arithmetic sum of fundamental and harmonic voltages Design voltage and current shall consider tolerances of ... Tuned filters

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Información clave en la especificación de

Filtros

Håkan Rörvall

Harmonic filters and applications

Jornadas Técnicas

25& 26 April.

Chile.

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ContainsPower Quality

•Cost running parameters

•Filter types

•Filter design

•Synchronized switching

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Cost running parameter

What generates the cost

� Engineering costs for specification of filtersSpecify the work to be done or the solution?

� Several solutions might do the job

� Parameters that have effect on the filter hardware costAim with filterSpecial demands and environment conditions

� Generated ( design ) harmonics and distortion demandsThe feeding networkType of filter BP; HP; C-filterProtection scheme

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Engineering costs for design of filters

� At User / User Consultant or Hardware Supplier

� Specify the work to be done or the solution?How to define the most competitive solutionThe system responsibility depends on influence

� Several solutions might do the job

� What is most important at evaluation scope or function?

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Aim with compensation, what is the need ?

� Reactive power needed, neglecteble harmonics on the busCapacitor bank(s with damping reactors )

� Reactive power needed, with harmonics on the busbut no extra distortion demands.Capacitor bank with anti resonance Compensation (strong detuned filters)

� Reactive power need, problems with harmonics on the bus and distortion demands.Filter(s)Selection of filter type BP; HP; C

Power Quality

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Special demands and environment conditions

� Pollution level ( IEC 60815 )Light ( 16 mm/kV ), Medium ( 20 mm/kV ), Heavy ( 25 mm/kV ), Very heavy ( 31 mm/kV ); [ actual is * sqrt(3) higher ]

� Seismic considerations

� Altitude when > 1 000 ma.s.l. impact on external insulation levelSpecify true insulation level and external insulation at sea level

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Special demands and environment conditions

�

Altitude correction factor

0,90

1,00

1,10

1,20

1,30

1,40

1,50

1,60

1,70

1,80

1,90

2,00

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

3400

3600

3800

4000

4200

4400

Altitude above sea level

Cor

rect

ion

fact

or *

BIL

IEC 60071-2 [exp (h/8150 )]

IEC 60694 [exp((h-1000)/8150 )] ; IEC 60044-1

IEC 60726 [6,25 % / 500 m ]

IEEE C57.12.00-1987 ; NBR10671/1989

IEEE Std 281

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Cost running parameter feeding network

� System voltage and insulation levelNetwork ( system ) impedance ( short-circuit power )Low short-circuit power problem for voltage distortion High short-circuit power problem for current distortion Other capacitive loads

� Voltage level

� Voltage fluctuations

� Frequency fluctuations

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The filter itself

� Number of branchesDistortion demandsVoltage raise at connection

� Type of filter (s)

Indoor filter with iron core

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Cost running parameter / Capacitor bank

Important difference installed power vs generated power

� Generated power is based on the line voltage to which the usefulpower refers. This is not effected by harmonic content and/or safety margins

� Installed power is based on design voltage voltage including extra safety margins

2syst12

2

gen U*C**1n

nQ ωωωω

−−−−====

2

2 n

nsyst2

2

1inst )C*

IU*

1nn

(*C*Q ��∞∞∞∞

ωωωω++++

−−−−ωωωω====

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Example:

Assume a network :

13,8 kV, 50 Hz ± 1 %

Ssc =800 MVA

Load / Harmonic source

6- pulse 18 MVA rectifier with harmonic generation according to table

6,1185037

6,5175035

7,3155031

7,8145029

13,1125025

13,1115023

19,895019

22,185017

46,365013

54,855011

107,63507

165,72505

11,31503

I [ A ]f [ Hz ]Order

Power Quality

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Filter system

BP-filter n=4,85

with Qgen = 9 Mvar

L=2,99 mH ± 2%C=144 µF ± 5 % ± dT- dEf = 50 Hz ± 1,0 %

dT temperature tolerance

dE element failure tolerance

Order Minimum Nominal MaximumFundamental 8278 8321 8359

3 14 15 175 1071 593 4297 134 111 9711 30 26 2413 20 18 1617 7 6 619 6 5 423 3 3 225 3 2 229 1 1 131 1 1 135 1 1 137 1 1 1

Sum harmonics 1292 783 601 VTotal sum 9571 9104 8960 V

Installed power 12,434 11,252 10,899 Mvar

Capacitor voltageComponent tolerance

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The capacitor bank power is ~ U²� According to standard the capacitor units shall be able to operate

at 110 % of rated voltage

� According to standard the capacitor voltage shall be calculated as the arithmetic sum of fundamental and harmonic voltages

� Design voltage and current shall consider tolerances of components and fluctuations in network conditions

� Bank power and voltageOptimization

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Cost running parameter / Capacitor bank margins

Order Minimum Nominal Maximum Order Minimum Nominal MaximumFundamental 8278 8321 8359 Fundamental 8278 8321 8359

3 14 15 17 3 14 15 175 1071 593 429 5 1071 593 4297 134 111 97 7 134 111 9711 30 26 24 11 30 26 2413 20 18 16 13 20 18 1617 7 6 6 17 7 6 619 6 5 4 19 6 5 423 3 3 2 23 3 3 225 3 2 2 25 3 2 229 1 1 1 29 1 1 131 1 1 1 31 1 1 135 1 1 1 35 1 1 137 1 1 1 37 1 1 1

Sum harmonics 1292 783 601 V Sum harmonics 1292 783 601 VTotal sum 9571 9104 8960 V Total sum 9571 9104 8960 V

Installed power 12,434 11,252 10,899 Mvar Installed power 12,434 11,252 10,899 MvarPower change 0,0% 0,0% 0,0%

Fundamental safety margin 0%Harmonic safety margin 0%

Component tolerance Component tolerance

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Cost running parameter / Reactor

� Reactor power ~2*pi*f*L*I²

� Design spectra

� Loss demands ( loss evaluation )

� Short-circuit current / Thermal load current ( if > 25 rule of thumb )

� Insulation demands across terminals and to earth

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Cost running parameter / Resistor

� Resistor power

� Insulation demands acrossterminals and to earth Type of cubicle

� Demands regarding resistance changes cold to hot

� Cooling

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Cost running parameter summary

Main parameters when external conditions is given

� Capacitor bankInstalled power, design power ( I.e. based on design voltage )

� ReactorReactor power, Inductance and design current spectra

� ResistorResistor power, Insulation level

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Types of filtersPower Quality

FilterAn equipment generally constituted of reactors, capacitors and resistors if required, tuned to present a known impedance over a given frequency range. [IEC 61642 ]

Tuned filtersA filter with a tuning frequency, which differs by no more than 10 % from the frequency which is to be filtered. [ IEC 61642 ]

Damped filterA filter with low, predominantly resistive, impedance over a wide band of frequencies. [ IEC 61642 ]

Detuned filtersA filter with a tuning frequency more than 10% below the lowest harmonic frequency with considerable current/voltage amplitude. [ IEC 61642 ]

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Filter types

� Bandpass filterL + C

� Highpass filterL // R + C

� C-type filter ( filter with extra low fundamental losses )(L+C2) // R + C1

Power Quality

R

C1

L

C2

R

C1

L

C2

R

C1

L

C2

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Bandpass filter L + C

� Cost efficient, few components

� Low impedance at tuning frequency

� Capacitive below tuning frequency

� Inductive above tuning frequency

� Low damping

� Quality factor q= �n*L/R(fn)at tuning frequency

� Common as detuned not dampedfilters in distribution networks

Power Quality

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Bandpass filter L + C

The tuning harmonic n will be:

Impedance

C**j1

L**j)(Zωωωω

++++ωωωω====ωωωω

C*L*f**21

n1ππππ

====

Power Quality

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Highpass filter L // R + C

� Band pass plus resistor

� Capacitive below tuning frequency

� Inductive/Resistive above tuning frequency

� Damped filter

� Preferred for medium/higher tuning

� Filter quality factor q= R(fn) /�n*L at tuning frequency is controlled by the parallel resistor

Power Quality

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Highpass filter L // R + C


Impedance

C*L*f**21

n1ππππ

====

C**j1

RL**jR*L**j)(Z

ωωωω++++

++++ωωωωωωωω====ωωωω

)(I*RL**j*L**j

)(IR ωωωω++++ωωωω

ωωωω====ωωωω

Resistor current will be:

Power Quality

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C-type filter (L+C2) // R + C1

� High pass plus extra capacitor

� Frequency response similar to HP-filter

� Resistor “short-circuit” for fundamental implies very low fundamental losses

� Capacitive below tuning frequency Inductive/Resistive above tuning frequency

� Damped filter suitable for low/medium tuning

� Filter quality factor q= R(fn) /�n*L at tuning frequency is controlled by the parallel resistor

� Starts to be more common in distribution networks in Europe

Power Quality

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Impedance

)(I*R))2C**j/(1L**j(

))2C**j/(1L**j()(IR ωωωω++++ωωωω++++ωωωω

ωωωω++++ωωωω====ωωωω

Resistor current will be:

2C1C2C*1C*L

*f**2

1n

1 ++++ππππ

====

1C**j1

)R)2C**j/(1L**j())2C**j/(1L**j(*R)(Z

ωωωω++++

++++ωωωω++++ωωωωωωωω++++ωωωω====ωωωω

R

C1

L

C2

R

C1

L

C2

R

C1

L

C2

Power Quality

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Useful at low tuning ( n < 5 ) when damped filter are needed

Example

Qgen = 6 Mvar 11 kV± 5 %, 50 Hz ± 1,0%

Filter q-factor Tuning Losses fundamentalHighpass filter C-filter

( kW / phase ) ( kW / phase )

4 2,9 32,5 0,44 4,7 6,9 0,14 11 0,5 0,018 2,9 16,3 0,28 4,7 3,5 0,05

Power Quality

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Filter types summary

� Bandpass filterL + C

� Highpass filterL // R + C

� C-type filter ( filter with extra low fundamental losses )(L+C2) // R + C1

Power Quality

R

C1

L

C2

R

C1

L

C2

R

C1

L

C2

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Static compensation / Where to compensate?

� Highest point in the system is given by the bottleneck

� Compensation location is many time a compromise

� Close to the load gives best result in terms of load reduction

� Close to the load implies more sensitive to load changesthat might increase the need for a more expensive solutions

� Close to the load might imply several compensations on same bus which might be tricky if filters are used and also more switchgear equipment

Power Quality

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Control of generation demand

� Minimum generated power is given by system calculationsPresent and target power factor together with active power

� The banks can be tailor madeCapacitance is given by generation demand and tuning

� Maximum bank size is controlled by allowed voltage rise at connectionvoltage raise at connection dU=dQ/Ssc

� Distortion demands might require more reactive power generation than power factor demand

Power Quality

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Considerations for filter capacitor bank design

� For good unbalance protection minimum 2 units in parallel

� Risk for case rapture if parallel energy is too high

� Insulation demands internal and external

� Internal fused capacitors will have less capacitance change in case of element failures

Power Quality

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Preferred Type of Capacitor FusingFusing

Bank power and voltage

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Input data for calculation

Environment DefaultLocation in/outdoorAvailable space no limitationAltitude m.a.s.l. < 1 000Ambient temperature maximum + 40 °CAmbient temperature minimum - 25 ° CMaximum daily average temperature + 30 ° CWind load if outdoor 40 m / sSeismic demands SpecifyPollution level IEC 60815 MediumStandards IEC

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Supply networkSupply voltage kV + - %Fundamental frequency Hz ± %Voltage level for guarantees kVShort-circuit power 1) min. / max. kV MVAConnection voltage for filter kVShort-circuit power at filter bus MVASingle line diagram Guarantee demands noneOther capacitances on filter bus none

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Harmonic and reactive power generationHarmonic generation Spectra.( or type of load and apparent power )Reactive power generation Mvar(load power with power factor, present and target )Harmonic generation by other sources None

MiscellaneousPower line carrier system on feeding bus None

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Grounded system (HV)

Ungrounded system (MV)

t + 6.66 mst + 3.33 ms

t

t

tt + 5 ms

RS T S T

Capacitor switching transientsPower Quality

SwitchSync principle

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6

2

3

1

4

5

1 SwitchSync Relay

2 Voltage Transformer

3 Current Transformer(for adaptive control)

4 Synchronous closing command

5 HV Breaker

Capacitor switching transients

SwitchSync connection scheme

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Without SwitchSync controlled HV-BreakerClosure in an unfavourableposition.

Phase Voltage

Moment ofconnection

Time

With SwitchSync controlled HV-BreakerClosure at zero voltage

Phase Voltage

Moment ofconnection

Time

Capacitor switching transientsPower Quality

SwitchSync result

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)(

sin

c

Kcs

tL

R

s

QS

Ii

teLC

Ufi

2

2 2

=

∗∗∗∗=−

ϖ

LR

C

LN R

UU

Capacitor switching transients

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U

SwitchSync tolerance

What if the timing error is 1 ms?

� 20 ms = 360°

� 1 ms = 18°

� sin18 °= 0,309 (≈31%)

Current Transient

� Error 1 ms � factor 0.3 �peak 0.3 Is

Voltage Transient

� Max. 2 p.u.

� Error 1 ms �factor 0.3 �max. 0.6 p.u. OK!

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Sound generation

The main sound source is the reactor followed by the capacitor bank.

The impression of sound also depends in very high degree of the spectra.

Damping according to the A filter.

Damping dB(A)IEC 60651 table 4

-70-65-60-55-50-45-40-35-30-25-20-15-10

-505

10

10 16 25 40 63 100

160

250

400

630

1000

1600

2500

4000

6300

1000

0

1600

0

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Sound generation

Another important parameter is the propagation of sound waves

Frequencies 2 * the frequencies that be found in the spectra’s 2*fa 2*fb 2*fc 2*fdthe sum and difference of the different frequenciesfa±fb fa±fc fa±fd fb±fc fb±fd and fc±fd

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Environment and quality

ABB Capacitors

� ISO certificate according to ISO 9001 and 14000

� What is not recyclable can be burnt with limited impact on environment

� Using non toxic biodegradable oil( conventional)

� Non PCB ( All main capacitor supplier use non PCB impregnate, common demand in specifications )

Power Quality

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Thanks for you attention

Håkan Rörvall

Harmonic filters and applications

Documents

Información clave en la especificación de Filtros · the arithmetic sum of fundamental and harmonic voltages Design voltage and current shall consider tolerances of ... Tuned filters