Harmonic Treatment In Industrial Power .ppt

HARMONIC TREATMENT IN INDUSTRIAL POWER SYSTEMS

Presented by Stefanos Manias

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JUNE 2002

CONTACT INFORMATION Stefanos N. Manias National Technical University of Athens Phone: +3010-7723503 FAX: +3010-7723593 E-mail: [email protected] Mailing Address National Technical University of Athens Department of Electrical and Computer Engineering 9, Iroon Polytechniou Str, 15773 Zografou Athens, Greece

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PLAN OF PRESENTATION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

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DEFINITIONS CATEGORIES OF POWER QUALITY VARIATIONS HARMONIC DISTORTION SOURCES IN INDUSTRIAL POWER SYSTEMS EFFECTS OF HARMONICS ON ELECTRICAL EQUIPMENT HARMONIC MEASUREMENTS IN INDUSTRIAL POWER SYSTEMS HARMONIC STANDARDS HARMONIC MITIGATING TECHNIQUES GENERAL PASSIVE AND ACTIVE FILTER DESIGN PROCEDURES DESIGN EXAMPLES CONCLUSIONS

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WHY HARMONIC ANALYSIS ? When a voltage and/or current waveform is distorted, it causes abnormal operating conditions in a power system such as: 







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Voltage Harmonics can cause additional heating in induction and synchronous motors and generators. Voltage Harmonics with high peak values can weaken insulation in cables, windings, and capacitors. Voltage Harmonics can cause malfunction of different electronic components and circuits that utilize the voltage waveform for synchronization or timing. Current Harmonics in motor windings can create Electromagnetic Interference (EMI).

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









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Current Harmonics flowing through cables can cause higher heating over and above the heating that is created from the fundamental component. Current Harmonics flowing through a transformer can cause higher heating over and above the heating that is created by the fundamental component. Current Harmonics flowing through circuit breakers and switchgear can increase their heating losses. RESONANT CURRENTS which are created by current harmonics and the different filtering topologies of the power system can cause capacitor failures and/or fuse failures in the capacitor or other electrical equipment. False tripping of circuit breakers ad protective relays.

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HARMONIC SOURCES a) Current Source nonlinear load

Thyristor rectifier for dc drives, heater drives, etc.

Per-phase equivalent circuit of thyristor rectifier

b) Voltage source nonlinear load

Diode rectifier for ac drives, electronic equipment, etc

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Per-phase equivalent circuit of diode rectifier

JUNE 2002

INPUT CURRENT OF DIFFERENT NOLINEAR LOADS

TYPE OF NONLINEAR LOAD

TYPICAL WAREFORM

THD%

1.0

80% (high 3rd component)

0.5

C u r en t

1-φ Uncontrolled Rectifier

0.0

-0.5 -1.0

0

10

20

30

40

Time (mS)

1.0 0.5 0.0

C ur r e nt

1-φ Semicontrolled Rectifier Bridge

2nd, 3rd, 4th ,...... harmonic components

-0.5 -1.0

0

10

20

30

40

Time (mS)

1.0 0.5 0.0 -0.5 -1.0

7

80%

C ur r e nt

6 –Pulse Rectifier with output voltage filtering and without input reactor filter

0

10

20

30

40

5, 7, 11, ……….

Time (mS)

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1.0 0.5 0.0

40% 5, 7, 11, ………..

C u r ent

6 - Pulse Rectifier with output voltage filtering and with 3% reactor filter or with continues output current

-0.5 -1.0

0

10

20

30

40

Time (mS)

1.0 0.5 0.0

C ur r e n t

6 - Pulse Rectifier with large output inductor

28% 5, 7, 11, ………..

-0.5 -1.0

0

10

20 Time (mS)

30

40

1.0 0.5 0.0

15% 11, 13, ………..

C u r e nt

12 - Pulse Rectifier

-0.5 -1.0

8

0

10

20 Time (mS)

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30

40

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CURRENT HARMONICS GENERATED BY 6-PULSE CSI CONVERTERS HARMONIC

P.U PULSE

1 5 7 11 13 17 19 23

1.00 0.2 0.143 0.09 0.077 0.059 0.053 0.04

CURRENT HARMONICS GENERATED BY 12-PULSE CSI CONVERTERS

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HARMONIC

P.U PULSE

IEEE 519 std

1 5 7 11 13 THD

1.00 0.03-0.06 0.02-0.06 0.05-0.09 0.03-0.08 7.5%-14.2%

5.6% 5.6% 2.8% 2.8% 7.0%

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RECENT CURRENT MEASUREMENTS TAKEN IN AN INDUSTRIAL PLANT WITH 600 KVA, 20 KV/400 V DISTRIBUTION TRANFORMER

Current waveform and its respective spectrum at the inputs of a motor drive system

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Current waveform and its respective spectrum at the inputs of a motor drive system

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Current waveform and its respective spectrum at the secondary of the distribution transformer ( i.e. at the service entrance)

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DEFINITIONS

f (t) = Fourier Series of a periodic function f (t) = 

Co   C h cos  hωt  θ h  h 1

1 T C h  A 2h  B2h C o  o f ( t )dt , T 2 T A h  o f ( t ) cos(hωt )dt T 2 T B h  o f ( t ) sin( hωt )dt T

(1) (2) (3) (4)

h = harmonic order

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THD υ %  Percentage of the Total Harmonic Distortion of a nonsinusoidal voltage waveform 

h 2



THDi % 

2

 Vh V1

 100

Percentage of the Total Harmonic Distortion of a nonsinusoidal current waveform 



2

 Ih

h 2

I1

 100

Vh  hth

harmonic component of the voltage

I h  hth

harmonic component of the current

~ VH  RMS value of the voltage distortion 

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(5)

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(6)

~2 V  h

h 2

JUNE 2002

~ IH 

RMS value of the current distortion 

~ I

RMS value of a nonsinusoidal current =

 ~ V





~2  Ih

h 2

(7)

h 1

RMS value of a nonsinusoidal voltage =

~2  Vh 

(8)

h 1

THD υ %  HF 

Drive kVA  100 SC kVA 

HF  Harmonic Factor =

15

~2  Ih

 h 2 I 2h

h 5

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(9)

/ I1

(10)

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Drive kVA  Full load kVA rating of the Drive system SC kVA  Short Circuit kVA of the distribution system at the point of connection

SINUSOIDAL VOLTAGE NONSINUSOIDAL CURRENT

~~ P  V Ii,1 cos φ1

(11)

~~ ~~ Q  V Ii,1 sin φ1 , S  V I D  Distortion VA  S2  P 2  Q 2

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(12) (13)

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



~ ~ ~ D  S  V 2 Ii,21  V 2 2

2



~2  Ii,h

(14)

h 2

P  Ii,1   cos φ1 λ  True Power Factor    S  I 

(15)

 Distortion Factor  Displace ment Factor NONSINUSOIDAL VOLTAGE AND NONSINUSOIDAL CURRENT



 ~ ~ ~ ~ P   Vh Ih cos φ h , Q   Vh Ih sin φ h h 1

D  Distortion Power

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

h 1

  SnmS*nm n m n m

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

(16)



* S S  n m

(17)

n m n m

JUNE 2002

(18)

S2  P 2  Q 2  D 2

S





 

~ 2~ 2 ~~ 2 ~~ V I  V  h h 1 I1  V1 IH h 1



~ ~  VH IH



2

2   V~H ~I1 2 

 S12  S2N

(19)

~~ S1  Fundamental Apparent Power  V1 I1 S N  Nonfundamental Apparent Power



 

 



~~ 2 ~ ~ 2 ~ ~ 2 S2N  V1 IH  VH I1  VH IH

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~~ V1 IH  Current Distortion Power

(20)

~ ~ VH I1  Voltage Distortion Power

(21)

~ ~ VH IH  Harmonic Apparent Power

(22)

S2H  PH2  N 2H  Total Harmonic Active Power   Total Harmonic Non Active Power

(23)

X C  Reactance of the capacitor   VL-L  2 / VAR 3phase

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Harmonic sequence is the phase rotation relationship with respect to the fundamental component. Positive sequence harmonics ( 4th, 7th, 10th , ……. (6n+1) th ) have the same phase rotation as the fundamental component. These harmonics circulate between the phases. Negative sequence harmonics ( 2nd, 5th, 8th ……… (6n-1) th ) have the opposite phase rotation with respect to the fundamental component. These harmonics circulate between the phases. Zero sequence harmonics ( 3rd, 6th, 9th, ….. (6n-3) th ) do not produce a rotating field. These harmonics circulate between the phase and neutral or ground. These third order or zero sequence harmonics, unlike positive and negative sequence harmonic currents, do not cancel but add up arithmetically at the neutral bus.

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EXAMPLE 1 SINUSOIDAL VOLTAGE-NONSINIMUSOIDAL CURRENT A periodic, sinusoidal voltage of instantaneous value v  200 2 sin ωt Is applied to a nonlinear load impedance. The resulting instantaneous current is













i  2 20 sin ωt  45o  10 sin 2ωt  60o  10 sin 3ωt  60o

given by:



Calculate the components P, Q, D of the apparent voltamperes and hence calculate the displacement factor, the distortion factor and the power factor.

Solution

v  200 2 sin ωt













i  2 20 sin ωt  45o  10 sin 2ωt  60o  10 sin 3ωt  60o



The presence of the nonlinearity causes frequency components of current (i.e. the second and third harmonic terms) that are not present in the applied voltage. The rms voltage and current at the supply are:

~ V  200V ~2 I  20 2  10 2  102  6  102 A 2

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The apparent voltamperes at the input is therefore given by

~ 2~ 2 S  V I  2002  6  10 2  24  106  VA  2 2

In this example only the fundamental frequency components are common to both voltage and current. Therefore, the real power P and the apparent power Q are

~~ P  V I1 cos ψ1 ψ1 = displacement angle between the fundamental of the voltage and the fundamental of the current

 200  20 cos 45o 

4000 W 2

~~ Q  V I1 sin ψ1  200  20 sin 45o 

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4000 VA 2

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 ~I  ~I   ~I  ~I   200 10  10   8  10

~ D2  V2 ~  V2

2

2 1 2 3

2

2

2

2

6

 VA  2

~ ~ P2  Q2  D2  V2 I 2

~~ ~ P V I1 cos ψ1  I1    cos ψ1  PF  power factor     ~~ S VI  I 1 Displacement factor  cos ψ1   0.707 2 I 20 Distortion factor  1   0.817 I 600 Therefore, the power factor is

PF 

23

1 2  0.577 2 6

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EXAMPLE 2 NONSINUSOIDAL VOLTAGE-RL LOAD





A periodic, sinusoidal voltage given by v  2 200 sin ωt  200 sin 5ωt  30o is applied to a series, linear, resistance-inductance load of resistance 4Ω and



fundamental frequency reactance 10Ω. Calculate the degree of power factor improvement realizable by capacitance Compensation when

f1  50HZ.

~

Solution. The rms terminal voltage V is given by

~ ~2 ~2 V  V1  V5

 200 2  200 2 Therefore

~ V  283V Z1  4  j10

Z1  10.8

1  tan 1 10 / 4   68.2o

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 5  51  50 Z5  4  j50

Z5  50

 5  tan 1  50 / 4   85.4o The instantaneous load current is given by









200  200  sin t  68.2 o  sin 5t  30o  85.4o  50  10.8  ~ The rms load current I is therefore given by i  2

~  2  ~   ~ 2 ~ 2 ~ 2  V1   V5  I  I1  I5      Z   Z1   5 

2

 18.52 2  4 2  359A 2

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Apparent voltamperes S at the load terminals in the absence of capacitance is therefore

~ ~ 2 S2  V 2 I 2  28.72  10 6  VA 

P

Average power

In this case is

n

~ ~ ~~ ~ ~ P   Vn In cos  L  V1 I1 cos 1  V2 I2 cos  2  ... 1

 200  18.52 cos 68.2o  200  4  cos 85.4o  1440 W The power factor before compensation is therefore

PF 

26

P S



1440 28.72  10

6

 0.27

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EXAMPLE 3 NONSINUSOIDAL VOLTAGE AND NONSINIMUSOIDAL CURRENT

A periodic, nonsinusoidal voltage with instantaneous value given by







v  2 200 sin ωt  200 sin 2ωt - 30o is applied to a nonlinear impedance. The resulting current has an instantaneous value given by















i L  2 20 sin ωt  45o  10 sin 2ωt  60o  10 sin 3ωt  60o Calculate the components SLR , SLX , SLD of the load apparent voltamperes and compare thee with the classical values PL , Q L , D L respectively. Solution.

   2 20 sin  ωt  45   10 sin  2ωt  60   10 sin 3ωt  60 

v  2 200 sin ωt  200 sin 2ωt - 30o

iL 

o

o

o

Note that the presence of the load nonlinearity causes a frequency component of load current (I.e. the third harmonic term) that is not present in the supply voltage.

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The rms voltage and current at the supply are given by

~ V 2  200 2  200 2  8 10 4 V 2

~2 IL  202  102  102  6  102 A 2 ~ ~ The load apparent voltamperes SL therefore has a value defined in terms V and I L ~ ~ 2 S2L  V 2 IL2  48 106  VA 

Instantaneous expressions of the hypothetical currents



iR , iX , iD

i R  2 20 cos 45o sin t  10 cos 300 sin  2t  30o 



 

2 ~2  ILR  20 cos 45o  10 cos 30 o





2





11 10 2 A 2 4



are given by

i X   2 20 sin 45o cos ωt  10 sin 300 cos 2ωt  30o



2 2 9 ~2  ILX   20 sin 45o   10 sin 30 o   10 2 A 2 4

i D  2 10 sin  3t  60 o 

~2  ILD  10 2 A 2

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Note that current components i R , i X contain only those harmonic terms which are common to both voltage and current. These are therefore consistent with the n1 terms.

~

~

~

The rms load current components ILR , ILX , ILD are found, as expected to sum

~ to the total rms load current IL

11 9  ~2 ~2 ~2 ~  ILD  ILR  ILD  10 2  1     6 10 2  IL2 4 4 

Components

S

2 LR

S

of the apparent voltamperes can now be obtained

~ 2 ~ 2 11 2 2  V ILR  10  8  10 4  22  10 6  VA  4

2 LX

~ 2~ 2 9 2 2  V ILX  10  8 10 4  18 106  VA  4

2 LD

~ 2~ 2 2  V ILD  10 2  8  10 4  8 10 6  VA 

S

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SLR , SLX , SLD

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The component voltamperes are seen to sum to the total apparent voltamperes

S2LR  S2LX  S2LD  106  22  18  8  48 106  VA  2  S2L Components





1



2

n

~ ~ V  n1 In1 cos ψ n1 

PL2   

PL , Q L , D L of SL are found as follows:



o

 200  20  cos 45  200  10  cos 30 2



 100 20 2  10 3



 10 6 2 2 

30

3



2





o 2

2





 106 8  3  4 6  20.8  10 6  S2LR

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

Q 2L   





1



2

n

~ ~ V  n1 In1 sin ψ n1 

 200  20  sin 45o  200  10  sin 30o





2



 10 6 2 2  1  14.6  10 6  S2LX

D 2L  S2L  PL2  Q 2L

  48  20.8  14.6 106  12.6  106  VA  2  S2LD From the possible compensation viewpoint it is interesting to note that SLX and Q L differ by significant amount. SLX could be defined as “that component of the load apparent voltamperes that Is obtained by the combination of supply voltage harmonics with quadrature Components of corresponding frequency load current harmonics”.

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Similarly the definition of active voltamperes

SLR

could be given by “that

component of the load apparent voltamperes that is obtained by the combination of supply voltage harmonics with in-phase components of corresponding frequency load current harmonics”. Both

SLR and SLX

are entirely fictitious and non-physical. The active

SLRIs not to be compares in importance with the average power PL which is a real physical property of the circuit. Term SLR Is merely the analytical complement of term SLX voltamperes

Term

SLX

the energy-storage reactive voltamperes, is that component

of the load apparent voltamperes that can be entirely compensated (for sinusoidal supply voltage) or minimized (for nonsinusoidal supply voltage) by energy-storage methods.

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Voltage and current profiles in a commercial building

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HARMONIC STANDARDS 

International Electrotechnical Commission (IEC) European Standards. - EN 61000-3-2 Harmonic Emissions standards were first published as IEC 55-2 1982 and applied only to household appliances. It was revised and reissued in 1987 and 1995 with the applicability expanded to include all equipment with input current  16A per phase. However, until January 1st, 2001 a transition period is in effect for all equipment not covered by the standard prior to 1987. - The objective of EN 61000-3-2 (harmonics) is to test the equipment under the conditions that will produce the maximum harmonic amplitudes under normal operating conditions for each harmonic component. To establish limits for similar types of harmonics current distortion, equipment under test must be categorized in one of the following four classes.

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CLASS-A: Balanced three-phase equipment and all other equipment except that stated in one of the remaining three classes. CLASS-B: Portable electrical tools, which are hand held during normal operation and used for a short time only (few minutes) CLASS-C: Lighting equipment including dimming devices. CLASS-D: Equipment having an input current with special wave shape ( e.g.equipment with off-line capacitor-rectifier AC input circuitry and switch Mode power Supplies) and an active input power 600W. - Additional harmonic current testing, measurement techniques and instrumentation guidelines for these standards are covered in IEC 1000-4-7.

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•

IEEE 519-1992 United States Standards on harmonic limits

-

IEEE limits service entrance harmonics. The IEEE standard 519-1992 limits the level of harmonics at the customer service entrance or Point of Common Coupling (PCC). With this approach the costumer’s current distortion is limited based on relative size of the load and the power supplier’s voltage distortion based on the voltage level. IEEE 519 and IEC 1000-3-2 apply different philosophies, which effectively limit harmonics at different locations. IEEE 519 limits harmonics primarily at the service entrance while IEC 1000-3-2 is applied at the terminals of end-user equipment. Therefore, IEC limits will tend to reduce harmonic-related losses in an industrial plant wiring, while IEEE harmonic limits are designed to prevent interactions between neighbors and the power system.

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POWER QUALITY STANDARDS – IEEE 519-1992 STANDARDS

TABLE I CURRENT DISTORTION LIMITS FOR GENERAL DISTRIBUTION SYSTEMS (120-69000 V)

37

Isc/IL

<11

11
35
TDD

<20*

4.0

2.0

1.5

0.6

0.3

5.0

20<50

7.0

3.5

2.5

1.0

0.5

8.0

50<100

10.0

4.5

4.0

1.5

0.7

12.0

100<1,000

12.0

5.5

5.0

2.0

1.0

15.0

>1,000

15.0

7.0

6.0

2.5

1.4

20.0

Source: IEEE Standard 519-1992. Note: Even harmonics are limited to 25 percent of the odd harmonic limits above. Current distortions that result in a direct current offset; for example, half wave converters are not allowed. Table I is for 6-pulse rectifiers. For converters higher than 6 pulse, the limits for characteristic harmonics are increased by a factor o f q/6 , where q is the pule number, provided that the amplitudes of noncharacteristic harmonics are less than 25 percent. *All power generation equipment is limited to these values of current distortion, regardless of actual ISC/IL. Where ISC = Maximum short circuit at PCC. And IL = Average Maximum demand load current (fundamental frequency component at PCC).

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TABLE II LOW VOLTAGE SYSTEM CLASSIFICATION AND DISTORTION LIMITS IEEE 519-1992 STANDARTS

Special Applications

General System

Dedicated System

Notch Depth

10%

20%

50%

THD (Voltage)

3%

5%

10%

Notch Area (AN)*

16,400

22,800

36,500

Source: IEEE Standard 519-1992. Note: The value AN for another than 480Volt systems should be multiplied by V/480 . The notch depth, the total voltage distortion factor (THD) and the notch area limits are specified for line to line voltage. In the above table, special applications include hospitals and airports. A dedicated system is exclusively dedicated to converter load. *In volt-microseconds at rated voltage and current.

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TABLE III LIMITS OF THD% IEEE 519-1992 STANDARDS

39

SYSTEM Nominal Voltage

Special Application

General Systems

Dedicated Systems

120-600V

3.0

5.0

8.0

69KV and below

-

5.0

-

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TABLE IV PROPOSED IEC 555-2 CLASS D STANDARDS for power from 50 to 600W

40

Harmonic

Relative limits Milliamps/Watt

Absolute Limits Amps

3

3.4

2.30

5

1.9

1.14

7

1.0

0.77

9

0.5

0.40

11

0.35

0.33

13

linear extrapolation

0.15 (15/n)

IEEE PESC-02

JUNE 2002

METHODOLOGY FOR COMPUTING DISTORTION Step 1: Compute the individual current harmonic distortion at each dedicated bus using different Software programs (i.e. SIMULINK, SPICE, e.t.c.) or tables that provide the current distortion of nonlinear loads. Step 2: Compute the voltage and current harmonic content at the Point of Common Coupling (PCC) which is located at the input of the industrial power system. - Each individual harmonic current at the PCC is the sum of harmonic current contribution from each dedicated bus. - The load current at PCC is the sum of the load current contribution from each dedicated bus. - The maximum demand load current at PCC can be found by computing the load currents for each branch feeder and multiply by a demand factor to obtain feeder demand. Then the sum of all feeder demands is divided by a diversity factor to obtain the maximum demand load current.

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Step 3: Choose a base MVA and base KV for the system use the following equations in order to compute individual and total current and voltage harmonic distortions at PCC and any other point within the power system. 3 MVA  10 b (24) Ib= Base current in Amps  Amps 3kVb

Zs = System impedance = MVAb= Base MVA,

MVA b MVA sc

p.u.

(25)

MVAsc= short circuit MVA at the point of interest

VH= Percent individual harmonic voltage distortion =

I  h  h   Zs   100 Volts Ib

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IEEE PESC-02

(26)

JUNE 2002

  THD υ % 

2 1   Vh  2  h  2 

V1

 100

2   2   Ih    THD i %   h  2   100 I1

(27)

h = harmonic order IH = Percent individual harmonic distortion =

Ih  100 IL

(28)

Isc = Short Circuit current at the point under consideration. IL = Estimated maximum demand load current

Isc MVA sc  S.C. Ratio = Short circuit Ratio  I L MVA D

(29)

MVAD = Demand MVA

43

IEEE PESC-02

JUNE 2002

K Factor = Factor useful for transformers design and specifically from transformers that feed Adjustable Speed Drives





 h

h 1

2

 Ih      IL 

2 (30)

ONCE THE SHORT CIRCUIT RATIO IS KNOWN, THE IEEE CURRENT HARMONIC LIMITS CAN BE FOUND AS SPECIFIED IN TABLE I OF THE IEEE 519-1992 POWER QUALITY STANDARDS USING THE ABOVE EQUATIONS VALUES OF IDIVINDUAL AND TOTAL VOLTAGE AND CURRENT HARMONIC DISTORTION CAN BE COMPUTED AND COMPARED WITH THE IEEE LIMITS

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IEEE PESC-02

JUNE 2002

Step 4: If the analysis is being performed for CSI-type drives then the area of the voltage notch AN should also be computed. -

At this point an impedance diagram of the under analysis industrial power system should be available. The Notch Area AN at the PCC can be calculated as follows.

AN = AN1 + AN2 + …………. V . microsec

(31)

AN1 , AN2 , …… are the notch areas contribution of the different busses

A N1 

Source inductance A NDR1 Source inductance  the sum of inductances from PCC to the drive (32)

ANDR1 : Notch area at the input of the drive

45

IEEE PESC-02

JUNE 2002

Step 5: Determine preliminary filter design.

Step 6: Compute THDv and THDi magnitudes and impedance versus frequency plots with filters added to the system, one at a time. SIMULINK or PSPICE software programs can be used for final adjustments. Step 7: Analyze results and specify final filter design.

46

IEEE PESC-02

JUNE 2002

EXAMPLE OF A SYSTEM ONE LINE DIAGRAM

47

IEEE PESC-02

JUNE 2002

System impedances diagram which can be used to calculate its resonance using PSPICE or SIMULINK programs

48

IEEE PESC-02

JUNE 2002

TYPES OF FILTERS 1) Parallel-passive filter for current-source nonlinear loads

• Harmonic Sinc • Low Impedance • Cheapest • VA ratings = VT (Load Harmonic current + reactive current of the filter)

49

IEEE PESC-02

JUNE 2002

2) Series-passive filter for voltage-source nonlinear loads

• Harmonic dam • High-impedance • Cheapest • VA ratings = Load current (Fundamental drop across filter + Load Harmonic Voltage)

50

IEEE PESC-02

JUNE 2002

3) Basic parallel-active filter for current source in nonlinear loads

51

IEEE PESC-02

JUNE 2002

4) Basic series-active filter for voltage-source in nonlinear loads

52

IEEE PESC-02

JUNE 2002

5) Parallel combination of parallel active and parallel passive

6) Series combination of series active and series passive

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JUNE 2002

7) Hybrid of series active and parallel passive

8) Hybrid of parallel active and series passive

54

IEEE PESC-02

JUNE 2002

9) Series combination of parallel-passive and parallel-active

10) Parallel combination of series-passive and series-active

55

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JUNE 2002

11) Combined system of series-active and parallel-active

12) Combined system of parallel-active and series-active

56

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JUNE 2002

A SIMPLE EXAMPLE OF AN INDUSTRIAL POWER DISTRIBUTION SYSTEM

57

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JUNE 2002

HARMONIC LIMITS EVALUATION WHEN POWER-FACTOR-CORRECTION CAPASITORS ARE USED -

-

As it can be seen from the power distribution circuit the power-factorcorrection capacitor bank, which is connected on the 480 Volts bus, can create a parallel resonance between the capacitors and the system source inductance. The single phase equivalent circuit of the distribution system is shown below.

Rtot VS

Ltot

IS

If

C

Ih

AC Source

Harmonic Load

Z in

Using the above circuit the following equations hold:

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IEEE PESC-02

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2 kVLL   X  R sys   cos  tan 1   , MVA sc  R   2 kVLL  1 X   Xsys   sin  tan    , MVA sc  R  

R sys  Xsys 

R sys α

2

Xsys α

2

(33)

(34)

α = The turns ratio of the transformer at PCC 2 1000  kVLL R tr  R pu  kVA tr

2 1000  kVLL X tr  X pu  kVA tr

59

IEEE PESC-02

(35)

(36)

JUNE 2002

R tot  R sys  R tr

(37)

X tot  Xsys  X tr Xc 

2 1000  kVcap

C

(39)

kVAR cap 1 ωX c

Xc 

(40)

1 ωC

X tot L tot  ω

60

(38)

(41)

X tot  2 πf

IEEE PESC-02

(42)

JUNE 2002

The impedance Zin looking into the system from the load, consists of the parallel combination of source impedance R and the  jX tot tot capacitor impedance

Zin 

 R tot  jωL tot     j / ωC 

1 R tot  jωL tot  j ωC 1 1 ωo L tot  , fo  ωo C 2 πωo

(43)

(44)

The equation for Zin can be used to determine the equivalent system impedance for different frequencies. The harmonic producing loads can resonate (parallel resonance), the above equivalent circuit. Designating the parallel resonant frequency by ω(rad/sec) or (HZ) f o and equating the o inductive and capacitive reactances.

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IEEE PESC-02

JUNE 2002

-

Harmonic current components that are close to the parallel resonant frequency are amplified. Higher order harmonic currents at the PCC are reduced because the capacitors are low impedance at these frequencies. The figure below shows the effect of adding capacitors on the 480 Volts bus for power factor correction.

This figure shows that by adding some typical sizes of power factor correction capacitors will result in the magnification of the 5 th and 7th harmonic components, which in turns makes it even more difficult to meet the IEEE 519-1992 harmonic current standards .

62

- Power factor correction capacitors should not be used without turning reactors in case the adjustable speed drives are >10% of the plant load.

IEEE PESC-02

JUNE 2002

EXAMPLE Let us examine an industrial plant with the following data: Medium voltage = 20KVLL -

Low voltage = 0.4 KVLL

-

Utility three phase short circuit power = 250 MVA X For asymmetrical current, the ratio of system impedance  2.4

-

R

The Transformer is rated: 1000 KVA, 20 KV-400 Y/230 V Rpu = 1%, Xpu = 7% - The system frequency is: fsys = 50 HZ.

63

- For power factor correction capacitors the following cases are examined: a. 200 KVAR b. 400 KVAR c. 600 KVAR d. 800 KVAR

IEEE PESC-02

JUNE 2002

The parallel resonant frequencies for every case of power factor correction is calculated as follows:

 20   sin tan 250

  2.4   1.4769Ω

20 2 R sys   cos tan 1  2.4   0.6154Ω 250 2

X sys α

1

20  50 0.4

R sys  0.6154 50 2  0.000246Ω

Xsys  1.4769 50 2  0.000591Ω 1000   0.4  2 R tr  0.01   0.00160Ω 1000 1000   0.4  2 X tr  0.07   0.0112 Ω 1000

64

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R tot  0.000246  0.0016  0.001846Ω X tot  0.000591  0.0112  0.011791Ω 0.011791 L tot   37.55  10  6 H 2  π  50 Case a:

1000   0.4  2 Xc   0.8 Ω 200 1 C   3.98 10 3 F 2 π  50  0.8

fo 

1 2 π  37.50  10  6  3.98  10 3

 412.18HZ

For 200 KVAR, the harmonic order at which parallel resonance occurs is:

h  412.18 50  8.24

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Case b:

1000   0.4  2 Xc   0.4 Ω 400 C  7.96 10 3 F f o  291.45HZ h  5.83

Case c:

1000   0.4  2 Xc   0.267 Ω 600 C  11.94 10 3 F f o  237.97 HZ h  4.76

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Case d:

1000   0.4  2 Xc   0.2 Ω 800 C  15.92  10 3 F

f o  206.08HZ h  4.12 It is clear for the above system that in the 600 KVAR case, there exists a parallel resonant frequency f o close to the 5th harmonic.

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IEEE PESC-02

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POWER FACTOR CORRECTION AND HARMONIC TREATMENT USING TUNED FILTERS -

Basic configuration of a tuned 3-φ capacitor bank for power factor correction and harmonic treatment.

Simple and cheap filter  Prevents of current harmonic magnification 

68

IEEE PESC-02

JUNE 2002

-

IN ORDER TO AVOID HARMONIC MAGNIFICATION WE CHOOSE A TUNED FREQUENCY < FITH HARMONIC (i.e 4.7) The frequency characteristic of the tuned filter at 4.7 is shown below

As it can be seen from the above figure significant reduction of the 5 th harmonic is achieved. Moreover, there is some reduction for all the other harmonic components.

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IEEE PESC-02

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The single phase equivalent circuit of the power distribution system with the tuned filter is shown below

Using the above circuit the following equations hold:

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f os 

1 1

= Resonant frequency of the series filter (45)

2π Lf  C  2 2 f  1000 kV 1 2 πf  X c cap Lf    C   2 πf os  2  2 πf os  2 2 π   f os  2  kVAR cap





(46)

The new parallel combination is having resonant frequency when

1 ωo L tot  ωo L f  0 ωo C fo 

1

1

2 π  L tot  Lf   C 2

(parallel resonance)

= resonance frequency of the (47) equivalent distribution circuit

Also

R tot  jωL tot If  I h  R tot  j ωL tot  ωL f  1 ωC

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IEEE PESC-02

(48)

JUNE 2002

Is  I h 

j  ωLf  1 / ωC  R tot  j  ωL tot  ωLf  1 ωC

Vh  Is   R tot  jωL tot 

 R tot  jωL tot   

(49)

(50)

1   ω C    Zin  1 R tot  jωL tot  jωLf  j ωC 

 R tot  jωL tot    

R tot  j  

72

jω L f  j

1   ωC   1  ωL tot  ωL f   ωC  jωL f  j

IEEE PESC-02

(51)

JUNE 2002

As it was discussed before Selecting f o  235HZ or 4.7 th harmonic With

Lf 

KVcap= 0.4 , 2

50 1000   0.4 

2  π   235 2  600

KVARcap= 600

 68.45 10 6 H  38.45μH

The new parallel combination is having resonant frequency:

fo  with

fo 

1

2π

  L tot  Lf   C

L tot  37.55 10 6 H L f  38.45 10 6 H

C  11.94 103 F 1

2  π  76 10 6 11.94 103

h  167.16 / 50  3.43

73

we have

 167.16HZ

(without Lf was 4.76)

IEEE PESC-02

JUNE 2002

The following table shows the variation of Parallel resonant frequency With and without resonant inductor Parallel Resonant f0

74

KVAR

C(mF)

Without Lf

200

3.98

8.80

115.3μH

4.08

400

7.96

6.22

57.7μH

3.66

600

11.94

5.08

38.45μH

3.43

800

15.92

4.40

29.5μH

3.08

IEEE PESC-02

With Lf

JUNE 2002

SIMULATED RESULTS USING MATLAB/SIMULINK T1

i -

+

C

motor

.

+ v -

380kw/490rpm

V

compens

Bus Bar (horiz)2

T Ground (i nput)

200m cabl e 4x240

V1 Ground (output)1

-

i

Current Measurement4

+

Vol tage Measurement3 + v -

Gnd

+ v -

50m cabl e 4x1

voltage Series RLC Bra nch Scope3

i

+

-

Source Scope1

itot Scope2

+

i -

Scope4 Scope

Current Measu rement6 Bus Bar (hori z)3

Source1

chock2%5 chock2%3

chock2%1

AC Voltage Source Ground (input)8 Ground (input)4

Ground (input)5 Ground (output)

Current Measurement5 i -

+

+

i -

Current Measurement3 Bus Bar (hori z)7 AC Current Source7

Bus Bar (hori z)5

AC Current Source4

Series RLC Branch3

Series RLC Branch2

AC Current Source5

AC Current Source8 AC Current Source6

AC Current Source3 Bus Bar (hori z)6

Bus Bar (horiz)4

Ground (input)2

-

i

+

Ground (input)3 Current Measurement1

Bus Bar (hori z)1 AC Current Source1 AC Current Source2

Series RLC Branch1

AC Current Source Bus Bar (horiz)

Ground (input)1

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JUNE 2002

SIMULINK RESULTS

76

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JUNE 2002

SIMULINK RESULTS

77

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JUNE 2002

ACTIVE FILTERING

Parallel type

78

Series type

IEEE PESC-02

JUNE 2002

RESULTS OF ACTIVE FILTERING 2500 1500

25

500

20 [% I1]

I [A]

30

-500

15 10

-1500

5 0

-2500 0

5

10

15

20 25 Time [ms]

30

35

2

40

5

8

11

14 17 Harmonics

20

23

Input current of a 6-pulse Rectifier driving a DC machine without any input filtering 35% 30%

2500

25% [%I1]

I Dynacomp [A]

5000

0

20% 15% 10%

-2500

5%

-5000

0%

0

10

20

30

40

Time [ms]

Input current with Active Filtering

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IEEE PESC-02

2

5

8

11

14

17

20

23

Harmonics

JUNE 2002

1000

14 12 10 [% U1]

U [V]

500 0

8 6 4

-500

2 -1000 0

5

10

15

20 25 Time [ms]

30

35

0

40

2

5

8

11

14 17 Harmonics

8

11

14 17 Harmonics

Typical 6-pulse drive voltage waveform 1000

23

14 12

500

10 [% U]

U [V]

20

0

8 6 4

-500

2 -1000 0

5

10

15 20 25 Time [ms]

30

35

40

0 2

5

20

23

Voltage source improvement with active filtering

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SHUNT ACTIVE FILTERS By inserting a parallel active filter in a non-linear load location we can inject a harmonic current component with the same amplitude as that of the load in to the AC system.

LF

C

Equivalent circuit

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ADVANTAGES OF THE SHUNT OR PARALLEL ACTIVE FILTER 

Low implementation cost.



Do not create displacement power factor problems and utility loading.





82

Supply inductance LS, does not affect the harmonic compensation of parallel active filter system. Simple control circuit.



Can damp harmonic propagation in a distribution feeder or between two distribution feeders.



Easy to connect in parallel a number of active filter modules in order to achieve higher power requirements.



Easy protection and inexpensive isolation switchgear.



Easy to be installed.



Provides immunity from ambient harmonic loads.

IEEE PESC-02

JUNE 2002

WAVEFORMS OF THE PARALLEL ACTIVE FILTER

Source voltage

Load current

Source current

A. F. output current

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PARALLEL ACTIVE FILTER EQUATIONS

IC  GI L

G1  0

(52)

G h 1

ZL VS  I LH  ZL ZL ZS  ZS  1 G 1 G ZL 1 VS 1 G IL   I LH   ZL 1  G Z  ZL ZS  S 1 G 1 G IS 

If

ZL  ZS h 1 G h

(53)

(54)

(55)

Then the above equations become

I C  I Lh

(56)

ISh  1  G  I LHh  1  G 

84

VSh 0 ZL

IEEE PESC-02

(57)

JUNE 2002

I Lh  I LHh 

VSh ZL

(58)

Equation (55) is the required condition for the parallel A.F. to cancel the load harmonic current. Only G can be predesign by the A.F. while Zs and ZL are determined by the system.

For pure current source type of harmonic source Z L  ZS and consequently equations (53) and (55) become

IS I LH

(59)

 1  G 

(60)

1  G h  1 ZS

= Source impedance

I LH

= Is the equivalent harmonic current source

Z L = Equivalent load impedance G = equivalent transfer function of the active filter

85

Equation (59) shows that the compensation characteristics of the A.F. are not influenced by the source impedance, Zs. This is a major advantage of the A.F. with respect to the passive ones.

IEEE PESC-02

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VdC C

• The DC bus nominal voltage, VdC, must be greater than or equal to line voltage peak in order to actively control i C . • The selection of the interface inductance of the active filter is based on the compromise of keeping the output current ripple of the inverter low and the same time to be able to track the desired source current. • The required capacitor value is dictated by the maximum acceptable voltage ripple. A good initial guess of C is:  2 VdC  Vφn t max i Cdt 3 Also LF  0 di φL C max Δv Cmax  dt Vφn = peak line-neutral voltage



VdC = DC voltage of the DC bus of the inverter i φL = Line phase current

Δv Cmax = maximum acceptable voltage ripple,

i C = Phase current of the inverter

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P-Q THEORY For identifying the harmonic currents in general the method of computing instantaneous active and reactive power is used. Transformation of the three-phase voltages v u , v v and v w and the threephase load currents i Lv , i Lu and i Lw into α-β orthogonal coordinate.

 vα   v    β

 i Lα   i    Lβ 

87

2 1  3  0

 1/ 2

2 1  3  0

 1/ 2

3/2

3/2

IEEE PESC-02

 1/ 2 

 vu   v   v  v w  

 3 / 2

 1/ 2  3 / 2





 i Lu   i   Lv   i Lw 

JUNE 2002

Then according to p - q theory, the instantaneous real power p L and the instantaneous imaginary (reactive) power q L are calculated.

 vα  pL   q   v β  L 

vβ   i Lα  v α   i Lβ 

where

88

 p L  pL  p L  ~ pL 

DC + low frequency comp. + high freq. comp.

 q L  qL  q L  ~ qL 

DC + low frequency comp. + high freq. comp.

IEEE PESC-02

JUNE 2002

~

The conventional active power is corresponding to pL, the conventional reactive ~ power to q L and the negative sequence to the 2 f components of p L and q L. The commands of the three-phase compensating currents injected by the shunt active conditioner, iCu , iCv and iCware given by:

 iCu      i Cv    i   Cw 

2  3 

 

1  1/ 2  1/ 2

0   vα  3/2   - vβ   3 / 2

vβ  v α 

1

 p     q 

p = Instantaneous real power command q  = Instantaneous reactive power command

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Substituting

p  ~ pL    Current Harmonics compensation is achieved  ~ q  q L 

 p  ~ pL   Current Harmonics and low frequency variation   ~ Components of reactive power compensation q  q L  q L 

 p  p L  ~ pL  Current Harmonics and low frequency variation    Components of active and reactive power compensation q  q L  ~ q L 

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HARMONIC DETECTION METHODS

i)

Load current detection iAF= iLh It is suitable for shunt active filters which are installed near one or more non-linear loads.

ii)

Supply current detection iAF= KS iSh Is the most basic harmonic detection method for series active filters acting as a voltage source vAF.

iii) Voltage detection It is suitable for shunt active filters which are used as Unified Power Quality Conditioners. This type of Active Filter is installed in primary power distribution systems. The Unified Power Quality Conditioner consists of a series and a shunt active filter.

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SHUNT ACTIVE FILTER CONTROL a) Shunt active filter control based on voltage detection

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Using this technique the three-phase voltages, which are detected at the point of installation, are transformed to v d and v q on the dq coordinates. Then two first ~ ~ order high-pass filters of 5HZ in order to extract the ac components vd and vq from v d and v q . Next the ac components are applied to the inverse dq transformation circuit, so that the control circuit to provide the three-phase harmonic voltages at the point of installation. Finally, amplifying each harmonic voltage by a gain Kv produces each phase current reference.

iAF  K V  v h The active filter behaves like a resistor 1/KV ohms to the external circuit for harmonic frequencies without altering the fundamental components.  The current control circuit compares the reference current i AF with the actual current of the active filter i AF and amplifies the error by a gain KI . Each phase voltage detected at the point of installation, v is added to each magnified error signal, thus constituting a feed forward compensation in order to improve current controllability. As a result, the current controller yields three-phase voltage  references. Then, each reference voltage v i is compared with a high frequency triangular waveform to generate the gate signals for the power semiconductor devices.

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b) Reference current calculation scheme using source currents (is), load currents (iL) and voltages at the point of installation (vS).

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3-φ HYBRID ACTIVE-PASSIVE FILTER Compensation of current harmonics and displacement power factor can be achieved simultaneously.

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In the current harmonic compensation mode, the active filter improves the filtering characteristic of the passive filter by imposing a voltage harmonic waveform at its terminals with an amplitude VCh  KISh

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If the AC mains voltage is pure sinusoidal, then

ISh ZF  I Lh K  Z F  ZS



THDi 

 ZF  I   Lh K  ZF  ZS   h  2 IS1

• THDi decreases if K increases. • The larger the voltage harmonics generated by the active filter a better filter compensation is obtained. • A high value of the quality factor defines a large band width of the passive filter, improving the compensation characteristics of the hybrid topology. • A low value of the quality factor and/or a large value in the tuned factor increases the required voltage generated by the active filter necessary to keep the same compensation effectiveness, which increases the active filter rated power.

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Displacement power factor correction is achieved by controlling the voltage drop across the passive filter capacitor.

VC  βVT

Displacement power factor control can be achieved since at fundamental frequency the passive filter equivalent impedance is capacitive.

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HYBRID ACTIVE-PASSIVE FILTER

Single-phase equivalent circuit

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Single-phase equivalent circuit for 5th Harmonic

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This active filter detects the 5th harmonic current component that flows into the passive filter and amplifies it by a gain K in order to determine its voltage reference which is given by

vAF  K  i F5 As a result, the active filter acts as a pure resistor of K ohms for the 5 th harmonic voltage and current. The impedance of the hybrid filter at the 5 th harmonic frequency, Z5 is given by

Z5  j5ωL F 

K0

The active filter presents a negative resistance to the external Circuit, thus improving the Q of the filter.

K   rF

10

1  rf  K j5ωC F

VBUS5  0 ,

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IS5 

1 VS5 j5ωL T

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CONTROL CIRCUIT The control circuit consists of two parts; a circuit for extracting the 5 th current harmonic component from the passive filter iF and a circuit that adjusts automatically the gain K. The reference voltage for the active filter 

v AF  K  i F5

HARMONIC-EXTRACTING CIRCUIT The extracting circuit detects the three-phase currents that flow into the passive filter using the AC current transformers and then the α-β coordinates are transformed to those on the d-g coordinates by using a unit vector (cos5ωt, sin5ωt) with a rotating frequency of five times as high as the line frequency.

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SERIES ACTIVE FILTERS By inserting a series Active Filter between the AC source and the load where the harmonic source is existing we can force the source current to become sinusoidal. The technique is based on a principle of harmonic isolation by controlling the output voltage of the series active filter.

Equivalent Circuit

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- The series active filter exhibits high impedance to harmonic current and consequently blocks harmonic current flow from the load to the source.

VC  Output voltage of the A.F.  KGIS IS 

ZLIL VS  ZS  ZL  KG ZS  ZL  KG

(61)

(62)

G = Equivalent transfer function of the detection circuit of

harmonic current, including delay time of the control circuit.

G1  0

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,

G h 1

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(63)

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K = A gain in pu ohms The voltage distortion of the input AC source VSh is much smaller than the current distortion.

K  ZL h

If

and

K  ZS  ZL h

(64)

Then

VC  ZL I Lh  VSh

IS  0

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(65)

(66)

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HYBRID SERIES AND SHUNT ACTIVE FILTER

At the Point of Common Coupling provides: • Harmonic current isolation between the sub transmission and the distribution system (shunt A.F) • Voltage regulation (series A.F) • Voltage flicker/imbalance compensation (series A.F)

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SELECTION OF AF’ S FOR SPECIFIC APPLICATION CONSIDERATIONS AF Configuration with higher number of * is more preferred Compensation for Specific Application

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Active Filters Active Series

Active Shunt

Hybrid of Active Series and Passive Shunt

Hybrid of Active Shunt and Active Series

Current Harmonics

**

***

*

Reactive Power

***

**

*

Load Balancing

*

Neutral Current

**

Voltage Harmonics

***

Voltage Regulation

***

Voltage Balancing

***

Voltage Flicker

**

***

Voltage Sag&Dips

***

*

*

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* **

*

**

*

**

* *

**

*

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CONCLUSIONS   

        

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Solid State Power Control results in harmonic pollution above the tolerable limits. Harmonic Pollution increases industrial plant downtimes and power losses. Harmonic measurements should be made in industrial power systems in order (a) aid in the design of capacitor or filter banks, (b) verify the design and installation of capacitor or filter banks, (c) verify compliance with utility harmonic distortion requirements, and (d) investigate suspected harmonic problems. Computer software programs such as PSPICE and SIMULINK can be used in order to obtain the harmonic behavior of an industrial power plant. The series LC passive filter with resonance frequency at 4.7 is the most popular filter. The disadvantages of the the tuned LC filter is its dynamic response because it cannot predict the load requirements. The most popular Active Filter is the parallel or shunt type. Active Filter technology is slowly used in industrial plants with passive filters as a hybrid filter. These filters can be used locally at the inputs of different nonlinear loads. Active Filter Technology is well developed and many manufactures are fabricating Active filters with large capacities. A large number of Active Filters configurations are available to compensate harmonic current, reactive power, neutral current, unbalance current, and harmonics. The active filters can predict the load requirements and consequently they exhibit very good dynamic response. LC tuned filters can be used at PCC and the same time active filters can be used locally at the input of nonlinear loads.

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REFERENCES [1] [2] [3] [4] [5] [6]

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RECOMMENDED PRACTICES ON HARMONIC TREATMENT IEEE Std. 519-1992, ΄΄IEEE Recommended Practices and Requirements for Harmonic Control in Electric Power Systems΄΄, 1993. IEC Sub-Committee 77B report, ΄΄Compatibility Levels in Industrial Plants for Low Frequency Conducted Disturbances΄΄, 1990. IEC Sub-Committee 77A report, ΄΄Disturbances Caused by Equipment Connected to the Public Low-Voltage Supply System Part 2 : Harmonics ΄΄, 1990 (Revised Draft of IEC 555-2). UK Engineering Recommendation G.5/3: ΄΄Limits for Harmonics in the UK Electricity Supply System΄΄, 1976. CIRGE WG 36.05 Report, ΄΄Equipment producing harmonics and Conditions Governing their Connection to the Mains power Supply΄΄, Electra, No. 123, March 1989, pp. 20-37. Australian Standards AS-2279.1-1991, ΄΄Disturbances in mains Supply Networks-Part 2: Limitation of Harmonics Caused by Industrial Equipment΄΄, 1991.

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DEFINITIONS [7] J. Arriilaga, D.A. Bradley, and P.S. Bodger, ΄΄Power System Harmonics΄΄,New York: Wiley, 1985. [8] N. Shepherd and P. Zand, ΄΄Energy flow and power factor in nonsinusoidal circuits΄΄, Cambridge University Press, 1979. EFFECTS OF HARMONICS [9] J.M. Bowyer, ΄΄Three-Part Harmony: System Interactions Leading to a Divergent Resonant System΄΄, IEEE Trans. on Industry Applications, Vol. 31, No. 6, Nov/Dec 1995, pp. 1341-1349. [10] R.D. Hondenson and P.J. Rose, ΄΄Harmonics: the Effects on power Quality and Transformers΄΄, IEEE Trans. on Industry Applications, Vol. 30, No.3, May/June 1994, pp. 528-532. [11] J.S. Subjak and J. S. McQuilkin, ΄΄Harmonics-Causes, effects, Measurements and Analysis: An Update΄΄, IEEE Trans. on Industry Applications, Vol. 26, No. 6, Nov/Dec 1990, pp. 103-1042. [12] P.Y. Keskar, ΄΄Specification of Variable Frequency Drive Systems to Meet the New IEEE 51 Standard΄΄, IEEE Trans. on Industry Applications, Vol.32, No.2, March/April 1996, pp. 393-402.

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[13] T.S. Key, ΄΄Cost and Benefits of Harmonic Current Reduction for Switch-Mode Power Supplies in a Commercial Building΄΄, IEEE Trans. on Industry Applications, Vol. 32, No. 5, September/October 1996, pp. 1017-1025.

[14]

[15] [16] [17]

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PASSIVE HARMONIC TREATMENT TECHNIQUES M.F. McGranaghan and D.R. Mueller, ΄΄Designing Harmonic Filters for Adjustable-Speed Drives to comply with IEEE-519 Harmonic limits΄΄, IEEE Trans. on Industry Applications, Vol. 35, No 2, March/April 1999, pp. 312-18. F.Z. Peng, ΄΄Harmonic Sources and filtering Approaches΄΄, IEEE Industry Applications Magazine, July/August 2001, pp. 18-25. J.K. Phipps, ΄΄A transfer Function Approach to Harmonic Filter Design΄΄, IEEE Industry Applications Magazine March/April 1997. S.M. Peeran, ΄΄Application, Design, and Specification of Harmonic Filters for Variable frequency Drives΄΄, IEEE Trans. on Industry Applications, Vol. 31, No. 4, July/August 1995, pp. 841-847.

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[18] J. Lai and T.S. Key, ΄΄Effectiveness of Harmonic Mitigation Equipment for Commercial Office Buildings΄΄, IEEE Trans. on Industry Applications, Vol. 33, No. 4, July/August 1997, pp. 11041110. [19] D.E. Rice,΄΄A Detailed Analysis of Six-Pulse Converter harmonic Currents΄΄, IEEE Trans. on Industry Applications, Vol. 30, No. 2, March/April 1994, pp. 294-304. [20] R.L. Almonte and Ashley, ΄΄Harmonics at the Utility Industrial Interface: A Real World Example΄΄, IEEE Trans. on Industry Applications, Vol. 31, No. 6, November/December 1995, pp. 14191426. [21] K. A. Puskarich, W.E. Reid and P. S. Hamer, ΄΄Harmonic Experiments with a large load-Commutated inverter drive΄΄, IEEE Trans. on Industry Applications, Vol. 37, No. 1, Jan/Feb. 2001, pp. 129-136. [22] L.S. Czarnecki and O. T. Tan, ΄΄Evaluation and Reduction of Harmonic Distortion Caused by Solid State Voltage Controller of Induction Motors΄΄, IEEE Trans. on Energy Conversion, Vol. 9, No. 3, Sept. 1994, pp. 528-421.

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[23] R.G. Ellis, ΄΄Harmonic Analysis of Industrial power Systems΄΄, IEEE Trans. on Industry Applications, Vol. 32, No. 2, March/April 1996, pp. 417-421. [24] D. Adrews et al, ΄΄ Harmonic Measurements, Analysis and Power factor Correction in a Modern Steel Manufacturing Facility΄΄, IEEE Trans. on Industry Applications, Vol. 32, No. 3, May/June 196, pp. 617-624. [25] D. Shipp and W. S. Vilcheck, ΄΄Power Quality and Line Considerations for Variable Speed AC Drivers΄΄, IEEE Trans. on Industry Applications, Vol.32, No.2, March/April 1996, pp. 403-410. [26] J. A Bonner et al, ΄΄Selecting ratings for Capacitors and Reactors In Applications Involving Multiple Single-Tuned Filters΄΄, IEEE Trans. on Power Delivery, Vol. 10, No. 1, Jan. 1995, pp. 547-555. [27] E. J. Currence, J.E Plizga, and H. N. Nelson, ΄΄Harmonic Resonance at a medium-sized Industrial Plant΄΄, IEEE Trans. on Industry Applications, Vol. 31, No. 4, July/August 1995, pp. 682690.

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[28] G. Lemieux, ΄΄Power system harmonic resonance. A document case΄΄, IEEE Trans. on Industry Applications, Vol. 26, No. 3, pp. 483-487, May/June 1990. [29] D. D. Shipp, ΄΄Harmonic Analysis and Suppression for electrical systems΄΄, ΙEEE Trans. on Industry Applications Vol. 15, No. 5, Sept./Oct. 1979.

[30] [31] [32] [33]

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ACTIVE HARMONIC TREATMENT TECHNIQUES H. Akagi, ΄΄New trends in active filters for Power conditioning΄΄, IEEE Trans. on Industry Applications, Vol. 32, Nov/Dec. 1996, pp. 1312-1322. Bhim Singh et al, ΄΄A Review of Active Filters for Power Quality Improvement΄΄, IEEE Trans. on Industrial Electronics, Vol. 46, No. 5, Oct. 1999, pp. 960-971. F. Z. Peng, ΄΄Application Issues of Active Power Filters΄΄, IEEE Industry Applications Magazine, Sep./Oct. 1998, pp. 22-30. S. Bhattacharga et al, ΄΄Active Filter Systems Implementation΄΄, IEEE Industry Applications Magazine, Sep./Oct. 1998, pp. 47-63.

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[34]

[35]

[36]

[37]

[38]

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S. Bhattacharya et al, ΄΄Hybrid Solutions for improving Passive Filter Performance in high power Applications΄΄, IEEE, Trans. on Industry Applications, Vol. 33, No. 3, May/June 1997, pp. 732-747. H. Akagi, ΄΄Control Strategy and site selection of a shunt active filter for damping of harmonies propagation in power distribution systems ΄΄, IEEE Trans. on Power Delivery, Vol. 12, Jan. 1997, pp.354-363. H. Fujita, T. Yamasaki, and H. Akagi, ΄΄A Hybrid Active Filter for Damping of Harmonic Resonance in Industrial Power Systems΄΄, IEEE Trans. on Power Electronics, Vol. 15, No. 2, March 2000, pp. 215-222. H. Akagi et al, ΄΄ Α shunt Active Filter Based on Voltage Detection for Harmonic Termination of a Radial power Distribution Line΄΄, IEEE Trans. on Industry Applications, Vol. 35, No. 3, May/June 1999, pp. 638-645. D. Rivas et al, ΄΄ A simple control scheme for hybrid Active Power Filter΄΄, IEE PESC-00, pp. 991-996.

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[39] L. Zhou and Zi Li, ΄΄A Novel Active Power filter Based on the Least compensation Current Control Method΄΄, IEEE Trans. on Power Electronics, Vol. 15, No. 4, July 2000, pp. 655-659.

[40]

[41]

[42] [43]

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MODELING IEEE Task Force on Modeling and Simulation, ΄΄Modeling and Simulation of the propagation of harmonies in electric power networks, Part I: Concepts, models, and simulation techniques΄΄, IEEE Trans. on Power Delivery, Vol. 11, No. 1, Jan. 1996, pp. 452-465. IEEE Task Force on Modeling and Simulation ΄΄Modeling and Simulation of the propagation of harmonies in electric power networks, Part II: Sample systems and examples΄΄, IEEE Trans. on Power Delivery, Vol. 11, No. 1, Jan. 1996, pp. 466-474. W. Jewel et al, ΄΄Filtering Dispersed harmonic Sources on Distribution΄΄, IEEE Trans. on Power Delivery, Vol. 15, No. 3, July 2000, pp. 1045-1051. N.K. Madora and A. Kusko, ΄΄Computer-Aided Design and Analysis of Power-Harmonic Filters΄΄ IEEE Trans. on Industry Applications, Vol. 36, No. 2, March/April 2000, pp.604-613.

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