AIRO INTERNATIONAL JOURNAL VOLUME 7 ISSN … SINHA... · Web viewIt is exquisite, shut circle...

AIRO INTERNATIONAL JOURNAL VOLUME 7 ISSN 23213914

The Experimental Studies of Transient Free Digital SVC Controller with Thyristor Binary Compensator at 125 KVA Distribution Transformer

1


2


Submitted by: Yashwant Sinha

Abstract— Electrical appropriation frameworks are bringing about extensive misfortunes as the heaps are far reaching, insufficient receptive influence pay offices and their shameful control. An

extensive static VAR compensator comprising of capacitor bank in five double successive strides in conjunction with a thyristor controlled reactor of littlest step size is utilized in the investigative

3


work. The work manages the execution assessment through expository studies and down to earth usage on a current framework. A quick acting mistake versatile controller is created suitable both for contactor and thyristor exchanged capacitors. The exchanging operations accomplished are without transient, basically no compelling reason to give inrush current constraining reactors, TCR size least giving little rates of nontriplen sounds, encourages stepless variety of responsive force contingent upon burden prerequisite so as keep up force component close solidarity dependably. It is exquisite, shut circle microcontroller framework having the elements of self regulation in versatile mode for programmed change. It is effectively tried on a dissemination transformer of three stage 50 Hz, Dy11, 11KV/440V, 125 KVA limit and the practical attainability and specialized soundness are built up. The controller created is new, versatile to both LT and HT frameworks and for all intents and purposes built up to be giving dependable execution.

Keywords— Binary Sequential switched capacitor bank, TCR, Nontriplen harmonics, step less Q control, transient free.

Introduction

It is all around reported in writing and through open exchanges at different levels that a generous force misfortune is occurring in our low voltage dispersion frameworks on record of poor force variable, because of lacking responsive force remuneration offices and their shameful control.

The extension of provincial force appropriation frameworks with new associations and taking into account agrarian segment in across the board remote zones, offering ascend to more inductive burdens bringing about low power components. In this manner there exists an incredible need to nearly coordinate responsive force with the heap to enhance power element, help the voltage and decrease the misfortunes.

In this paper, a more dependable, actually stable, quick arranging so as to act and ease plan is exhibited the thyristor exchanged capacitor units in five twofold successive steps. This empowers the responsive force variety with the minimum conceivable determination. Also a thyristor controlled reactor of the most reduced step size is worked is conjunction with capacitor bank, in order to accomplish constantly variable responsive force. Other than the upgrade transformer stacking ability the shunt capacitor likewise enhances the feeder execution, lessens voltage drop in the feeder and transformer, better voltage at burden end, enhances power element, enhances framework security with improved usage of transformer limit, gives scope for extra stacking, increments over all productivity, spares vitality because of diminished framework misfortunes, stays away from low influence variable punishment, and decreases most extreme interest charges.

A. SVC With Binary Sequential Switched Capacitors

The SVC is irreplaceable and taking into account demonstrated innovation for force variable adjustment and responsive force pay. Customarily SVC has been utilized as a shunt gadget that offers voltage strength and responsive force remuneration to the heap or at PCC. Subsequent to EPRI's (Electric Power Research Institute) arrival of FACTS systems in 1987 SVC's have developed in notoriety and are entrenched in force industry [1]-[3].

The Basin Electric Power Corporation introduced the main SVC in Nebraska in 1977 [4],[5]. The least complex design for a propelled shunt compensator basically comprises of the thyristor exchanged capacitor manage an account with every capacitor step associated with the framework through a thyristor switch. In the proposed paper capacitor bank step qualities are picked in twofold arrangement weights to make the determination little. An examination of exchanging homeless people demonstrates that transient free exchanging can happen if the accompanying two conditions are met [6],[7].

a) The thyristor is let go at the negative/positive crest of voltage, and/or

b) Capacitor is precharged to the negative/positive crest voltage.

The main condition can be met precisely by timing the control hardware and the second condition is just met promptly subsequent to exchanging off thyristor. The design for five capacitor bank ventures in twofold arrangement weight with thyristors switch is appeared in Fig. 1

B0

B1

B2

B3

B4

4


Thy-0

Thy1

Thy2

Thy3

Thy4

C0

C1

C2

C3

C4

..

..

..

Fig. 1. Thyristor Binary Compensation Scheme (TBC).

B. FC-TCR Scheme

The Fig. 2 shows the basic configuration of static compensator FC-TCR. In this case capacitor represents a thyristor switched capacitor bank in binary sequential steps (TBC) as explained earlier and L represents reactor with phase angle control [8]-[10].

Step Down Transformer 125 KVA 50Hz

Point of Common Coupling

Inductor

Capacitor

SSR5


Fig. 2. FC-TCR Scheme

The controllable scope of TCR terminating point αextends from 900 to 1800. If there should be an occurrence of perfect reactor of L Henry terminating edge of 900 results in full conduction with nonstop sinusoidal current stream. Essentially every one of the six air cored reactors are outlined with a normal resistance of 10 and inductance of 230 mH.

The accompanying "(1)" [6] outlines the connection between terminating point αand the current through inductor IL for perfect inductor having resistance tending towards zero while "(2)" speaks to the reasonable case considering resistance R .

IL =

V

21

(1)

1

−

α−

sin 2α

ωL

π π

V

α

0.5

m

6


sin 2

sin 2

β

I

(α) =

1

βα−)

(

+ −

L

2

2

2

2

7


2π

R

+X L

(2)

8


9


The following observations are important.

i) If α= θi. e. firing angle = phase angle sin(β- θ) = sin(β- α) = 0

and conduction angle = β- α= π

ii) Conduction angle should not exceed π The range of control angle αis θ≤α≤π

V

10


I α =L

=V Y

αθ)

1

Z

m TCR(

(3)

Where

11


1

sin 2

α sin 2

0.5

YTCR ( αθ)

=YMax

β

(

β α−) +

−

2π

2

12


2

(4)

This TCR acts like a variable admittance. By varying the firing angle α admittance changes and consequently fundamental current component which in turn gives rise to variation of reactive power

absorbed by reactor. Hence if α= θ = 85.50 continuous conduction of current take place. However, if firing angle is increased beyond this, non-sinusoidal currents are generated and hence harmonics get introduced. The rms value of nth order harmonic is expressed

as a function of αin the following equation.

V

2

−2 cos(

α−θ) sin n ( α−θ) +

I1

n

(α) = ×

−1)( α−θ)

sin( n

+1)(

13


Z

π sin( n

α−θ)

+

+

n −1

n +1

14


Where, n = 2k+1 and k = 1, 2, 3 . . .

(5)

C. Error Adaptive Power Factor Controller :

A spearheading work in the Error Adaptive Power Factor Controller [EAPFC] was finished by M.A. EI. Sharkawi et. al. [11],[12]. These EAPFC's don't make utilization of an inductor branch (TCR) as in SVC's however commitments to successful capacitor exchanging methods are prominent. The versatile VAR remuneration innovation was produced at the University of Washington with sponsorship of Bonneville Power Administration (BPA) and Southern California Edison (SCE). The undertaking was begun in 1980 and finished in 1993. Therefore identified with this work number of papers were distributed [13]-[16]. The significant work was conveyed in the configuration, advancement and usage of 15 kV class of versatile VAR compensator. The Adaptive Var Compensator (AVC), was strong state exchanged, paired ventured capacitor bank, used to repay any quickly changing responsive interest inside of one half cycle without presenting homeless people or sounds.

In the light of the considerable number of advancements that have been accounted for in the later past, the alluring elements for the controller to be created are recorded beneath which frames the fundamental subject of work under taken.

• It keeps up the force component at the PCC to any predetermined worth.

• It adjusts for quick variety in responsive force or voltages.

• Maximum remuneration time is 10 msec. (1/2 of a cycle).

• No homeless people or music are permitted to be available because of quick specific moments of exchanging in an all around composed way.

• It is versatile as in the measure of the pay is resolved and gave on a cycle by cycle premise.

• It can remunerate every stage freely which makes perfect for uneven frameworks.

• It keeps up the force variable at the PCC to any predetermined worth.

• Capacitors are estimated in parallel consecutive proportion for least size of exchanging steps (TBC).

The AVC can work in any of the accompanying modes –

• Reactive Power Compensation (RPC) mode: Maintaining solidarity or other craved force variable at the purpose of normal coupling (PCC) with an exactness of littlest capacitor bit and with the restriction of aggregate capacitance of the AVC per stage.

• Voltage bolster mode: Regulating the voltage at the purpose of or at some pre-indicated level utilizing under and/or over pay.

• Flicker Control mode: Used to decrease the quick changes in the voltage.

15


Any of the modes can be actualized at once and can be controlled by determined time booking [16]. The potential

uses of AVC are at burden end or at framework level remuneration. The heap end application incorporates those requiring quick pay, for example, timber factories, rock smashing plants, steel factories, lifts, circular segment heaters, pumps, electric footing. The circulation framework application incorporates receptive VAR remuneration, upgrade of voltage regulation, and avoidance of voltage breakdown,

discharged framework limit, diminishment in line misfortunes and expansion in productivity. The imaginative and valuable outline of the AVC has brought about commercialization of the gadget and reported in three US licenses [13],[17],[18]. All the above alluded controllers don't have any reactor part (TCR) thusly. To keep up the force component at solidarity, twofold stages required are high to diminish the determination. Yet at the same time these APFC's are strong, controllers obliging the sudden changes in receptive force request and decrease voltage flash.

Fig. 3. Proposed Scheme for TBC and TCR

D. Processor Based Static VAR Compensators:

In 1990, number of papers got distributed on microcontroller (Microprocessor) based static VAR compensator [19]. Additionally [20] gives the subtle elements of open circle control procedure of SVC; while in [19] equipment SVC model was produced for research center trials. The model comprises of FC-TCR plan. The control technique utilized depended on PD and PID. The paper [20] centered particular inductor control (TCR) through adding to a model. While in [21],[22] fluffy rationale control plan was utilized. The objective of this fluffy controller was to give most extreme damping and enhance soundness in the force framework.

II. THE PROPOSED BINARY SEQUENTIAL SWITCHED CAPACITORS AND TCR SCHEME

At the distribution transformer requiring total reactive power Q

for improving the power factor from some initial value Pf1 to the

desired value Pf2 at the load. This Q can be arranged in binary sequential ‘n’ steps, satisfying the following equation:

Q 2

n

C= 2

n1

+

21

C +2

0

C

16


(6)

+C

.........

2+C +2

The schematic graph of the capacitor bank in five double successive strides through contactors and with separate current constraining reactors is appeared in Fig 3. An inventive mistake versatile controller is planned, created and tried for exchanging operations of the capacitor bank as required for the framework under thought. It has the accompanying elements.

• The control system is blunder actuated to coordinate with the heap responsive force for the picked time interim.

• It takes out conceivable over remuneration and coming about driving force element.

• It is adaptable to pick required number of ventures according to the determination.

• Resolution can be made little with more number of steps.

• Simple on a fundamental level, rich in utilization and of minimal effort

• Possible to join the thought introduced in the controllers for expansive size transformers at substations.

The controller receives both current and voltage signals through CT and PT, perform necessary calculations through an in built program and generates the activating signals S0, S1, S2, S3 and

S4 so as to match the reactive power from the compensator with

the prevailing load demand. It calculates the reactive power with a microcontroller based processor along with data acquisition card and arrives at the compensation value and the corresponding steps to be kept on.

A. System Data for Experimental Set up:

Walchand college of Engineering, Sangli is getting the supply from State Electricity Board through 11 KV feeders and there are two transformers feeding various loads in the campus. Their ratings are as follows:

11 KV feeders of length 5 km Vishrambag substation to college premises have the following parameters.

Type of overhead line: -Mink 6/3.66

Over all Diameter = 11 mm; Sectional area= 63.1 mm2; Approximate Weight = 254.9 Kg./Km.;

Current Carrying Capacity = 174 A

D.C. Resistance per Km distance =0.49 Ohms. Reactance per Km distance =0.365 Ohms

III. HARDWARE IMPLEMENTATION

This segment portrays the different parts for KVAR detecting utilized as a part of the controller. The fundamental contrast in the middle of SVC and proposed KVAR controller is that previous handles the voltage regulation issue through TSC-TCR plan while the last performs smooth control with definite coordinating of responsive force bringing about enhanced voltage. This encourages pay of (slacking) receptive force by TSC-TCR plan termed as SVC (KVAR controller). It incorporates KVAR sensor, ADC converter, zero intersection indicators, door beat era for thyristor controlled reactor and additionally capacitor exchanging ON/OFF circuit with the assistance of microcontroller 89C51. The general piece chart and its execution as a TSC-TCR sort SVC on 11KV/433V, DY11, 125KVA, 3phase, 50Hz transformer at Walchand College of Engineering, Sangli has been appeared in Fig. 4

17


Fig.4. General Schematic Diagram of Digital SVC

Calculation of Reactive Power By Sampling:

At the purpose of regular coupling, on the 125 KVA transformer, all the research center burdens are associated. The real KVAR at PCC is found by detecting current and voltage through CT and PT. These detected signs are nourished to the information procurement ADC card. In the wake of testing these signs for half cycle are increased component by component and their normal worth taking into account extremity is acquired and in like manner responsive force is ascertained. The schematic of this inspecting process through ADC with Microcontroller 89C51 is appeared in Fig.5.

Digital KVAR Controller:

This shut circle advanced framework appeared in Fig. 6 detects the KVAr of the framework from the purpose of normal coupling (PCC). It is completed by getting I and V signals from CTs and PTs. Through the set point obsession, it is conceivable to set the PCC's jQ (responsive force) at any craved quality. Verging on favored state of solidarity force component can be gotten by setting KVAr set point = 0. The examination between set esteem and detected worth is done as takes after:

KVArerror = KVArset - KVArsensed = e(t)

Where e(t) is the error signal, a measure of KVAr difference at that time. This error signal is sampled and processed further by proportional and integral controller as shown in Fig. 7.

Fig. 5. Digital Data Acquisition through ADC

Fig. 6. Block Diagram of digital KVAR Controller.

Digital Controller :

It includes sampler, digital proportional, integral controller

18


and ADC

e(t)

Microco -

TCR pulses

e(k)

ntroller

ADC

Sampler

With PI

Control

Switching

Ts=2f

Algorithm

Signals

Fig. 7. Digital Controller

Sampling Rate Selection :

The example and hold circuit can be joined through ADC. The examining recurrence fs is kept just double the central recurrence (ff ) of 50 Hz (i.e. period Ts = 10 ms). The explanation for this is the thyristor dead time required for the susceptance control of the reactor loop (I(α)). If there should arise an occurrence of 2 heartbeat TCR per stage terminating edge αcan change from 900 to 1800 just once in a half cycle.

19


Once the conduction begins in both of the half cycles any adjustment in terminating edge of the same thyristor won't have any impact. This confines the inspecting recurrence, which can't be more than double the major recurrence. This is the powerlessness of thyristor to react at any self-assertive time moment and termed as thyristor dead time Td. For a 2 beat TCR this dead time is changing from 0 to T/2. Typically it is doled out to a normal estimation of T/4 (5 ms). Developing the same contention for 6 beat, delta associated TCR, testing recurrence might be expanded up to six times the essential recurrence (Ts = 6f 0), thyristor dead time turns out to be half of the T/6 i. e. T/12 (20/12 1.7 ms). This thyristor dead time Td and thyristor ≅terminating delay time Ty together can be spoken to by the exchange capacity,

C. Thyristor Controlled Reactor(TCR

varying as per “(5)”. Lagging KVAR is calculated by microcontroller and from lookup tables stored in the memory corresponding firing angle αis obtained. The lookup table provides the information regarding required KVAR and the corresponding firing angle α.

The yield of ADC changes from 00h to FFh for info variety of 0-5 volt d. c. (i. e. 100 KVAR slack) this numerical hex worth gives the accurate prerequisite of driving KVAR. This estimation of KVAR is utilized for capacitor exchanging methodology. Resultant exchanged capacitor KVAR is intentionally continued the main side. This adjusting so as to drive KVAR is then repaid the conduction length of time σ in the thyristor controlled reactor. The capacitor banks are organized in paired grouping structure i. e. in the variety of 16, 8, 4, 2, 1 code. Hence,

20


C5 = 16C1; C4 = 8C1; C3 = 4C1, and C2=2C1 with essential unit of 2.5 KVAR.

IV. EXPERIMENTAL RESULTS

All the above parts are manufactured, tried and executed at PCC of a 125 KVA, 433 volts circulation transformer. The heap was expanded from 30 Amp to 150 Amp. It is watched that without controller p.f. shifts from 0.8 to 0.85 while with created static Var compensator, it was in the middle of 0.99 slack to 0.99 lead. The points of interest of the framework execution with and without SVC are given in the Table I, II ,III, IV and V individually.

The voltage change, diminishment in regulation, decrease in feeder misfortunes, effectiveness of feeder and alleviation acquired in KVA interest are portrayed in Fig. 9 to Fig. 12 separately.

Financial Justification:

In the school grounds establishment state power sheets has been forcing punishments because of poor force component and over the top most extreme interest. The plan that is proposed takes out these punishments and school can profit the advantages of motivators by keeping up the force calculate closer to solidarity. On a normal the school is paying the punishments to the tune of Rs 25000/ - every month. The general establishment expense of the proposed plan is of around Rs/ - 1.2 lakh. Month to month investment funds because of motivating forces offered by state power sheets for development in the force variable from .96 to solidarity p.f. is of 5 to 6 % of the month to month bill. The normal month to month bill is around 5 lakh. Subsequently straight way month to month motivating forces acquired are of around 17,000/ - . Additionally motivations are acquired because of lessening in most extreme interest charges roughly Rs. 3000/ - . Hence the payback period turns out to be of 6 months for the framework introduced.

21


TABLE I

DISTRIBUTION FEEDER PERFORMANCE WITHOUT COMPENSATOR

Sr.

Load

Power

Real

Reactive

Apparent

22


Receiving

Losses

%

%

No.

Current

Factor

Power

23


Power

Power

End Voltage

Watts

Voltage

Feeder

Amp.

24


Pf.

KW

KVAR

KVA

Volts

Regulatio

Efficiency.

25


26


n

01

30.00

27


0.70

15.6

15.9

022.3

430.10

48.6

0.68

28


99.69

02

60.00

0.72

31.9

30.8

044.4

29


427.25

194.4

1.34

99.39

03

90.00

0.74

30


48.9

44.5

066.1

424.9

437.4

2.00

31


99.11

04

110.0

0.76

61.2

52.3

080.5

422.78

32


653.4

2.41

98.94

05

135.0

0.78

33


76.7

61.5

098.3

420.69

984.1

2.92

98.73

34


06

165.0

0.80

95.6

71.7

119.5

418.27

35


1470.1

3.52

98.48

36


37


38


TABLE II

39


KVAR COMPENSATION IN BINARY SEQUENTIAL STEPS FOR THE CASES REFERRED IN TABLE I

40


41


42


Sr.

Compensated Reactive Power KVAR

TCR

Reduced

Reduced

TCR + Capacitor

Net Losses

No.

43


in

Value

Current

Losses

Losses

44


TCR+Capacitor+Feeder

Binary sequential Steps

KVAR

Amp.

Watts

45


Watts

losses

Q5

Q4

Q3

Q2

Q1

Lag.

46


Watts

47


48


01

-

-

10

5

49


2.5

1.6

21.00

23.8

47.9

71.17

50


02

-

20

10

-

2.5

1.7

43.20

100.8

55.9

51


156.7

03

40

-

-

5

-

00

52


66.60

239.5

3.75

243.25

04

40

53


-

10

-

2.5

0.2

83.60

377.4

5.12

382.52

54


05

40

20

-

-

2.5

1.0

105.30

598.8

55


24.4

623.2

06

40

20

10

-

2.5

56


0.8

132.00

940.9

18.45

959.35

57


58


59


TABLE III

60


61


RESULTS AFTER COMPENSATION FOR THE RESPECTIVE CASES OF TABLES I & II

62


Sr. No.

Receiving

%

%

Increased

Net

Relief in

63


End Volts

Voltage

Feeder

Load Current

64


Saving in

KVA

65


Reg.

Eff.

Capability

Loss. Watts

66


67


Amp

68


01

432.3

0.15

99.84

9.00

-23

6.7

69


02

431.6

0.31

99.68

70


16.80

38

12.5

71


03

430.9

0.49

99.51

23.40

194

17.2

72


04

430.2

0.62

99.38

73


26.40

271

19.3

74


05

429.6

0.79

99.22

29.70

361

21.6

75


06

428.7

1.01

99.02

33.00

511

76


24.0

77


78


79


TABLE IV

80


81


SYSTEM PERFORMANCE WITHOUT SVC

82


83


Sr.

Avg. Load

Avg.

Avg.

Active

Reactive

84


Apparent

Percent Voltage

Losses

Feeder

No.

Current

P.F.

Voltage

Power

Power

Power

85


Regulation

In

Efficiency

In Amp

In volts

86


In Kw

In KVAr

In KVA

watts

In %

1

87


30

0.8

430

17.9

13.4

22.36

0.66

88


48.6

99.69

2

60

0.82

428

89


36.4

25.35

44.35

1.16

194.4

99.39

3

90


90

0.83

426

55.1

37.19

66.48

1.63

91


437.4

99.11

4

110

0.83

424

92


67.0

45.24

80.84

2.09

653.4

98.94

5

93


135

0.84

422

82.8

53.28

98.46

2.56

94


984.1

98.73

6

150

0.85

419

95


92.5

56.6

108.44

3.25

1215

98.48

96


97


TABLE V

98


SYSTEM PERFORMANCE WITH SVC

99


100


Sr.

Load

Capacitor Bank

TCR

TCR

Line

101


PCC

Percent

Feeder

Increased

KVA

No.

Current

steps Used

Value

Current

Losses

Voltage

102


Voltage

Efficiency

Load

Relief

In

KVAr

Amps

103


In watts

In Volts

Regulation

In %

Capability

Amps

104


105


In Amps

1

24

10+5

1.6

106


2.5

31

432

0.23

99.8

6

4.46

2

49

107


20+5

0.0

0.1

130

431

0.46

99.27

108


11

7.95

3

74

20+10+5+2.5

0.39

0.5

295

430

0.69109


99.15

16

11.38

4

91

40+5

0.0

110


0.1

447

429

0.9

99.00

19

13.84

5

113

40+10+5111


1.62

2.7

689

428

1.15

98.9

22

15.66

112


6

127

40+10+5+2.5

0.9

1.5

870

426

1.61

98.8

113


23

15.94

V. CONCLUSION

A thorough static VAR compensator comprising of capacitor bank in five double successive strides in conjunction with a thyristor controlled reactor of littlest step size is utilized in the investigative work. The work manages the execution assessment through investigative and useful usage on a current framework. It is effectively tried on an appropriation transformer of three stage 50 Hz.

Dy11, 11KV/440V, 125 KVA limit. Hypothetical and down to earth results are coordinating with one another. It gives the accompanying advantages:

•Maintaining the force component at solidarity.

•Minimum feeder current and misfortune decrease.

•Improvement in appropriation feeder effectiveness.

•Improvement in the voltage at burden end.

•Relief in most extreme interest and viable use of transformer limit.

•Saving in month to month bill because of decrease in punishment by virtue of poor force variable, and diminishment in most extreme interest charges.

•Conservation of vitality happens.

•It is conceivable to get stepless control of Q firmly coordinating with burden prerequisites.

•The blend offers more prominent adaptability in control.

•There is considerable decrease in sounds produced because of little size of reactor utilized in the static VAR compensator.

REFERENCES

Hammad and B. Roesle, “New roles for static Var compensators in transmission system”, Brown Boveri Rev., Vol. 73, pp 314-320, Jun. 1986.

J. Kearly et. al., “Microprocessor controlled reactive power compensator for loss reduction in Rural Distribution Feeders”,

114


IEEE Transactions on power delivery, Vol. 6, No. 4. October 1991, pp. 1848-1855.

Narain G. Hingorani and L. Gyugyi, “Understanding FACTS” IEEE Press.

K. Stahllleopf, M. Wichelm, “Tighter Controls for Busier System”, IEEE Spectrum, April 1977, P 49-52.

J. Grahm, “Transient stability enhancement using Static Var Compensation”, Wart Verginia University, Thesis, 378, 3543 Engg. G76tc2, Oct. 1995.

L. Gyugyi, R. A. otto, T. H. Putman, “Principles and Application of Static Thyristor Controlled Shunt Compensations”, IEEE Transaction on Power Apparatus and Systems”, Vol. PAS 97, No. 51978, pp 1935-1945.

Celli, F. Pilo, S. B. Tennakoon, “Voltage Regulation on 25 KV A. C. Railway Systems by Using Thyristor Switched Capacitors”, 0-7803-6499-6/00 2000 IEEE.

Edwards, K. Mattern, E. Stacey, P. Nannery and J. Gubernick, “Advanced static Var generator employing GTO thyristors”, IEEE Trans. Power Del. VOl. 3, No. 4, pp1622-1627, Oct. 1988.

M. F. Iizarry, Silvestrini, PREDA mitigation of back to back capacitor switching transients on distribution circuits, San Juan PR00936.

Turan Gonen, “Electric power distribution system engineering”, CRC press, 2nd edition.

M. EI. Sharkawi, T. Williams, N. Buller, “An Adaptive Power Factor Controller for Three Phase Induction Generator”, IEEE tranction on Power App and Systems, Vol. PAS 104, No. 7, July 1985, pp1825-1831.

EI. Sharkawi, N. Buller, R. Yinger, “Development and Field testing of adaptive power factor controller, IEEE tranction on energy conservation, Vol. EC-2, No. 4, alce 1987.

Sharkawi, S. S. Vankuta, G. Andexler, Mingliang chen and Tony Huang, “Reactive Power Compensation”, us patent No. 5, 134, 356 July 28, 1992.

Bradley, J. A. Turner, D. S. Krchbial, “Lighting impuler test on adaptive power factor controller”, US Department of Engg-Bonneville power administration report No. ERJ 83-82, Sept. 23, 1983.

S. Cherulaupalli, H. E. Orton, “Adaptive power factor controller” powertect Enc. Project No. 148-88, No. 1988.

M. A. EI Sharkawi Et. al., “Development and field testing of adaptive flicker control for 15 KV systems”, paper number 94 sm 453-1 PWRD, PES summer meeting, San Fransco, July 25-28, 1994.

Sharkawi, S. S. Vankuta, G. Andexler, Mingliang chen and Tony Huang, “Reactive Power Compensation”, us patent No. 5, 134, 356 July 28, 1992.

Bradley, J. A. Turner, D. S. Krchbial, “Lighting impuler test on adaptive power factor controller”, US Department of Engg-Bonneville power administration report No. ERJ 83-82, Sept. 23, 1983.

115


S. Cherulaupalli, H. E. Orton, “Adaptive power factor controller” powertect Enc. Project No. 148-88, No. 1988.

Paul, S. Basu, R. Mondal, “A Microcomputer Controller static var compensator for power system laboratory experinemnts”, IEEE transaction on power systems. Vol. 7, No. 1, Feb. 1992, p. 371-376.

A Exporito, F. Varquez, C. Mitchell, “Microprocessor based control of a SVC for optimal load compensation”, IEEE Transactions on power delivery, Vol. 7 No. 2, April 1992.

Hiyama, W. Hubbi, T. Ortmeyer, “Fuzzy logic control scheme with variable geiin for static var comepnsator to enhance power system stability”, IEEE transactions on power systems, Vol. 14, 1 Feb. 1999, P186-191

.

*****

116

AIRO INTERNATIONAL JOURNAL VOLUME 7 ISSN … SINHA... · Web viewIt is exquisite, shut circle...

Documents

Transcript of AIRO INTERNATIONAL JOURNAL VOLUME 7 ISSN … SINHA... · Web viewIt is exquisite, shut circle...