46_TOV GIS SS

8/12/2019 46_TOV GIS SS

1/7

Temporary Overvoltages in Gas Insulated Substations

Connected by long HV Cables

Kiran Kumar Munji and Ravikumar Bhimasingu

Crompton Greaves Ltd

Global R&D CentreMumbai, India

[email protected]

Abstract Temporary overvoltages (TOV) are of importance

when determining stresses on equipment related to power-frequency withstand voltage, in particular for the energycapability of surge arrester (SA). The maximum continuous

operating voltage rating (MCOV) of the selected arrester should

be high enough so that neither the magnitude, nor the duration ofthe TOV exceeds the capability of the arrester. To ensure this,

the maximum TOV at/nearby arrestor location has to be

determined along with the maximum time that the system is

operated in the abnormal voltage state for breaker opening,

feeder energisation and single line to ground fault conditions. Inthis paper an attempt has been done to verify the withstand

capability of surge arresters in gas insulated substation (GIS)

during feeder energisation and single line to ground (SLG) fault

conditions. It also provides the necessary separation distance

between the arresters and protective equipment.

KeywordsTemporary overvoltage; Gas insulated substation;Surge arrester; Maximum continious operating voltage;

I. INTRODUCTION

Overvoltages can be caused by a number of system events,such as switching surges, line-to-ground faults, load rejectionand Ferro-resonance. Overvoltages in power system can betraditionally classified into 1) transient overvoltages 2)

temporary overvoltages. Transient overvoltage is defined asshort duration highly damped, oscillatory or non oscillatoryovervoltage, having duration of a few milli seconds or less. Itcan be classified into lightning, very fast front and switching.Temporary overvoltage is an oscillatory overvoltage i.e. at agiven location of relatively long duration (seconds, evenminutes) and is undamped and weakly damped. Main reasonsfor temporary overvoltage are switching or fault clearingoperations [1]. This voltage can be calculated using thecomputer program capable of modeling the distribution system.

Overvoltages may also originate during switching on andoff of capacitor banks into the network. These transientsgenerated due to overvoltages on either the HV or LV side ofthe transformer can combine with cable capacitance whichproduces standing waves with frequencies ranging fromfundamental to 10 kHz and amplitudes upto several times theoriginal ones, leading to electric stress and failure ofcomponents. Hence, in order to analyze these transients and toaccount the wide range of overvoltages originating from thesetransients, precise modeling of components is required. Toensure that the arrester TOV capability is not exceeded, the

maximum TOV at/nearby arrestor location has to bedetermined along with the maximum time that the system isoperated in the abnormal voltage state for breaker opening,feeder energisation and single line to ground fault conditions.

Many papers available in literature have explained aboutthe equipment modeling and transient analysis. Bollen et. al.[2] provided the information regarding power systemtransients. Information regarding lightning transients in powersystem and the validation of surge arrester rating to mitigate

them using coefficient of grounding (COG) was explained byWalsh et. al. [3]. whereas the information regarding highfrequency modeling of various components such astransmission lines and cables, transformers, source equivalents,loads and circuit breaker (CB) in case of transients eventsalong with necessary examples was provided by Durbak et. al.[4]. How cables with different lengths upon energizationindependently influence transients generated at point ofcommon coupling was analyzed by Moore et. al. [5].Information and necessity of high frequency modeling ofcomponents in case of transients was provided by [6-8].

In most cases, a single set of well qualified arrestersinstalled as close as possible to the GIS entrance (i.e. within afew meters) and with short connection leads, will protect a

comparatively long GIS bus. It is, therefore, not usually aquestion of choice between a metal-enclosed surge arresterwithin the GIS or a conventional porcelain type arrester at theGIS entrance but whether a GIS arrester is needed in addition.Provision of a single GIS arrester set only will provide goodprotection at its location, but any open disconnecting switchand breaker between the arrester and the GIS entrance could beleft unprotected.

II. SYSTEM DESCRIPTION AND EQUIPMENT MODELING

A. System DescriptionThe substation is a 220/33kV GIS connected through cables

at both the voltage levels so, there is no provision for lightingovervoltages in the system. The incoming of 220kV side of

substation is connected through 220kV cables of 30km length(4 incoming lines). These cables are connected to 220kV GISand again the power is transformed from 220kV to 33kVvoltage rating through a power transformer of 220/33/11kV,100MVA rating. The 33kV side of transformer is connected to33kV GIS and there after connected to 33kV distributioncables of 5km length (9 incoming lines).

Fifth International Conference on Power and Energy Systems, Kathmandu, Nepal | 28 - 30 October, 2013

8/12/2019 46_TOV GIS SS

2/7

Fig. 1. PSCAD implementation of the GIS substation

B. SourceThe source is modeled using a 3-phase and 1-phase short

circuit MVA ratings. Based on these MVA ratings andrespective X/R ratios the positive and zero-sequenceimpedances are calculated. Based on the above inputs positivesequence impedance Z1=0.316+j3.16 and zero sequenceimpedance Z0=0.6815+j6.815 are calculated for 220kVsource.

C. CablesThe range of frequencies of primary interest in a switching

transients study varies from the fundamental power frequencyup to about 10 kHz. For transient overvoltage study it isrequired that the cable systems should be modeled accuratelybecause a simple -section does not simulate reflections incables, and it is thus usually used only for steady state studies.The surge, propagating in cable systems and impedances of thecable systems are highly frequency dependent. Therefore, forhigh frequency transient studies, frequency dependent model isused.

Fig. 2. Representation of single core cable

Cables behave differently for different frequencies. Forexample, the resistance of the cable increases at higherfrequencies due to the skin effect and provide some dampingeffect to system response compared to normal power systemfrequencies. As switching frequencies involve wide range offrequencies it necessary to model frequency dependent modelof cables which includes travelling wave phenomena thereby

accurate response of system may be obtained [9]. There aretwo types of cables in system, single core XLPE cable of1000mm

2arranged in trefoil configuration are used for 220kV

(30km length) and three core XLPE cable of 400mm2shown in

Fig. 3 are used for 33kV (5km length). Single core cables haveconductor, insulation, shield, jacket and semi conductor (SC)shields as shown in Fig. 2. Frequency dependent phase modelis used for modeling both single and three core cables in

PSCAD. This Model uses curve fitting to duplicate thefrequency response of a line or cable. It is the most advancedtime domain model available as it represents the full frequencydependence of all line parameters [10](including the effect of afrequency dependent transformation matrix).

1. Conductor Stranded Circular Aluminium Conductor

2. Screen- Extruded Semi Conducting Compound

3. Insulation XLPE Compound

4. Insulation screen - Extruded Semi Conducting Compound

5. Insulation Screen (Metallic part)-Copper Tape

6. Inner sheath Extruded PVC Type ST-2 Compound

7. Galvanized Steel Strip Armoured

8. Outer sheath Extruded FR PVC Type ST-2 Compound9. FILLER PVC

Fig. 3. Arrangement of 33kV 400mm2cables

D. TransformersFor switching surge transient studies, the transformer modelused is a reduced order representation with less detail, in

comparison with a model used for insulation coordinationstudies. Usually a lumped parameter coupled-winding modelwith a sufficient number of R-L-C elements gives theappropriate impedance characteristics at the terminal within thefrequency range of interest. The nonlinear characteristic of the

220kV GIS

220kV GIS

220kV GIS

220kV GIS

CABLE220KV

CABLE220KV

CABLE220KV

CABLE220KV

220KVGIS

220KVGIS

220KVGIS

TX1

TX2

TX3

TXBAY1

TXBAY2

TXBAY3

GIS SA

AIS SA

33kV GIS1

33kV GIS2

33kV GIS3

33kV GIS4

33kV GIS5

33kV GIS6

33kV GIS7

33kV GIS8

33kV GIS9

CABLE1

CABLE2

CABLE3

CABLE4

CABLE5

CABLE6

CABLE7

CABLE8

CABLE9

BRK1A

BRK1B

BRK1C

BRK1D

BRK2A

BRK2B

BRK2C

BRK2D

BRK3A

BRK3B

BRK3C

BRK4A

BRK4B

BRK4C

BRK5A

BRK5B

BRK5C

BRK5D

BRK5E

BRK5F

BRK5G

BRK5H

BRK5I

RL RRL

E1A

E1B

E1C

E1D

E2A

E2B

E2C

E3A

E3B

E3C

E4A

E4B

E4C

E4D

E4E

E4F

E4G

E4H

E4I

AIS SA

0.01784

Cable # 1

0.043650.048150.05245

1.0 [m]

0.0 [m]

Conductor

Insulator 1

Sheath

Insulator 2

SC Layer 1

SC Layer 2

12

3


8/12/2019 46_TOV GIS SS

3/7

core should usually be included, although, the frequencycharacteristic of the core is often ignored. The transformer isrepresented by its short circuit impedance, magnetizinginductance and losses [11].

E. Surge arresterZnO surge arrester is composed of non-linear resistors

where overvoltage impulses can be diverted into current surgeswhile the energy of the wave is discharged. In this way, surgearresters limit the amplitude of the TOVs.

Surge arresters are preferably located close to theequipment to protect, in our case, at the terminal of the powertransformer and at feeder ends. The location of surge arrestersis shown in TABLE II. The protection level of the ZnO arresteris set with sufficient margin to the TOVs depending on thesystem grounding and operating conditions [12].

Metal-oxide surge arresters are capable of operating forlimited periods of time at power-frequency voltages above theirMCOV rating. The amount of overvoltage that a metal-oxidearrester can successfully withstand depends on the length oftime that the overvoltage exists [13]. Manufacturers candescribe the arrester overvoltage capability in the form of acurve that shows temporary power-frequency overvoltage

versus allowable time shown in Fig. 4. Surge arrester is usuallyrepresented by non linear V-I characteristics as shown inTABLE I. for TOV study.

TABLE I. V-ICHARACTERISTICS FOR SURGE ARRESTERS

Rated voltage (kV) 216kV 30kV

Highest system voltage (kV) 245 36

MCOV (kV) 178 25.5

Voltage at 5 kA (kV) 560 80



TABLE II. LOCATION OF SURGE ARRESTERS

216kV SA 30kV SA

220kV side of powertransformer (AIS)

33kv side of powertransformer (GIS)

Incoming of 220kV line (GIS) Incoming of 33kv line (GIS)

Fig. 4. Temporary overvoltage capability curve

F. Gas insulated substationFig. 5 shows the internal single line diagram of 220kV and

33kV GIS. The GIS components like spacer, Elbow, circuit

breaker, Earth switch (ES) and PT are represented by theirequivalent capacitance as shown in TABLE III.

Fig. 5. Single line diagram showing various components of GIS

TABLE III. SHUNT CAPACITANCE OF GISCOMPONENTS

GIS component Capacitance (pF)

Circuit breaker 50spacer 20

Elbow 45

Earth switch 45

PT 75

G. SwitchgearSwitchgear includes circuit breakers and vacuum switches,

which make or break circuits. In switching surge studies, theswitch is often modeled as an ideal conductor (zero impedance)when closed, and an open circuit (impedance) when open.

III. SIMULATION DETAILS &CASE STUDIES

For the GIS substation, the following 8 cases have beensimulated. The simulated single line diagram modeled in

PSCAD is shown in Fig. 1. It assumed that the voltagemeasurement is available at the surge arrester locations, namelyE1A, E1B, E1C, E1D, E2A, E2B, E2C, E2D, E3A, E3B, E3C,E4A, E4B, E4C, E4D, E4E, E4F, E4G, E4H and E4I. Also, atthese locations, surge arrestor currents and energy levels areavailable. The locations are shown in Fig. 1.

1) Case: 1BRK1A is closed with remaining breakers in open

condition. The case is run to check the overvoltage seen by theSA (216kV) located at the incoming of 220kv line of substationwhen energisation of a single 220kV cable. The case is run for500ms with energisation of BRK1A at 400ms and 405ms.

2) Case: 2BRK1A is closed with breakers BRK1B to BRK1D already

in ON condition. The case is run for 500ms with energisationof BRK1A at 400ms and 405ms.

3) Case: 3BRK3A is closed with breakers (BRK1A to BRK1D) and

(BRK2A to BRK2D) already in ON condition. The case is runfor 500ms with energisation of BRK3A at 400ms and 405ms.

0.1 1 10 100

320

340

360

380

400

420

440

460

46

48

50

52

54

56

58

60

62

216kV

30kV

Maximum time duration in seconds

VoltageperunitMCOV

220 (30)

220 1

220 2

21

220

33 1

33 2

30

33 1

33 2

33

30


8/12/2019 46_TOV GIS SS

4/7

4) Case: 4BRK3A is closed with breakers BRK3B to BRK3D already

in ON condition. The case is run for 500ms with energisationof BRK3A at 400ms and 405ms.

5) Case: 5BRK5A is closed with breakers BRK5B to BRK5I in OFF

condition. The case is run for 500ms with energisation ofBRK5A at 400ms and 405ms.

6) Case: 6BRK5A is closed with breakers BRK5B to BRK5I alreadyin ON condition. The case is run for 500ms with energisationof BRK5A at 400ms and 405ms.

7) Case: 7SLG fault is created at the end of 33kV cable. Fault is

created at 405ms which exists for 140ms and BRK5A clear thisfault at 545ms. The fault exists till 200ms.

8) Case: 8SLG fault is created at 220kv side of power transformer no

3. Fault is created at 405ms which exists for 140ms andBRK3C clear this fault at 545ms. The fault exists till 200ms.

The simulation is carried out for 500ms to let the transients

settle down to steady state condition. After 400ms breakeroperations are initiated at voltage zero (Vz= 400ms)

and voltage

peak (Vp= 405ms). The time step has to be coherent with thehighest frequency phenomenon appearing in the system duringthe transient under consideration. A value of one-tenth of theperiod corresponding to the highest frequency is advised. Thetime step has to be lower than the travel time of any of thepropagation elements of the network [14]. A value of half ofthis travel time is advised.

Fig. 6 & Fig. 7 show the voltage waveform at E1A for case:1, when BRK1A is closed at Vz and Vp respectively. In thesecases we have observed a voltage peak of -271.5kV and292.88kV. Fig. 8 to Fig. 11shows the voltage waveforms forthe case: 2. we have observed a voltage peak of 292.2kV at

E1A, which is 16% higher than the MCOV rating of SA. Thevoltage rise is less than the MCOV rating at other locations. Incase of SLG faults at 33kV and 220kV (Fig. 14 to Fig. 16) theovervoltage occur during breaker opening but persist for shortduration and they are below surge arresters TOV capabilitycurve (Fig. 4).

Fig. 6. Voltage wave form at E1A (energized at Vz) for Case 1

Fig. 7. Voltage wave form at E1A (energized at Vp) for Case 1

Fig. 8. Voltage wave form at E1A for Case2, energized at Vz

Fig. 9. Voltage wave form at E1B for Case2, energized at Vz

Fig. 10.Voltage wave form at E1A for Case2, energized at Vp

-300

-200

-100

0

100

200

300

380 400 420 440 460 480 500

Voltage(kV)

Time (ms)

PHASE-A PHASE-B PHASE-C

-200

-100

0

100

200

300

350 400 450 500

,

Voltage

(kV)

Time (ms)

Phase-A Phase-B Phase-C

-300

-200

-100

0

100

200

300

350 400 450 500

,

Voltage(kV)

Time (ms)


-300

-200

-100

0

100

200

300 350 400 450 500

Voltage(kV)

Time (ms)


-300

-200

-100

0

100

200

300

350 400 450 500

,

Voltage(kV)

Time (ms)



8/12/2019 46_TOV GIS SS

5/7

Fig. 11.Voltage wave form at E1B for Case2, energized at Vp

Fig. 12.Voltage wave form at E4A for Case5, energized at Vz

Fig. 13.Current through surge arrestor at 4A (SA4A) for Case 5 when cable isenergized at Vz

Fig. 14.Voltage wave form at E4A for Case7

Fig. 15.Current through surge arrestor at 4A (SA4A) for Case 7

Fig. 16.Voltage wave form at E2C for Case8

TABLE IV. SUMMARY OF RESULTS

Case Location Voltage peak

(kV)

%rise

( MCOV)

COG

Case 1 (Vz) E1A -271.55 107.8 -

Case 1 (Vp) E1A 292.88 116.3 -

Case 2 (Vz) E1A -287.59 114.2 -

E1B -234.91 93.3 -

Case 2 (Vp) E1A 292.2 116.1 -

E1B 224.3 89.1 -

Case 5 (Vz) E3A -39.17 108.6 -E4A -39.17 108.6 -

Case 5 (Vp) E3A -39.17 108.6 -

E4A -39.17 108.6 -

Case 6 (Vz) E4A -29.20 81.06 -

Case 6 (Vp) E4A 29.62 82.13 -

Case 7

(when fault occurs)

E4A -32.48 90.0 0.696

Case 7(when BKR opens)

E4A -54.12 150.0 -

Case 8

(when fault occurs)

E2C -235.25 93.4 0.755

Case 8

(when BKR opens)

E2C -340.94 135.4 -

IV. OBSERVATIONS FROM THE SIMULATIONS

It is observed that the values of peak over voltages aremore in the cases of breaker opening during faultclearance.

-200

-100

0

100

200

300

350 400 450 500

,

Voltage(kV)

Time (ms)


-40

-20

0

20

40

350 400 450 500

,

Voltage(kV)

Time (ms)


-0.00010

-0.00005

0.00000

0.00005

0.00010

350 400 450 500

Current(kA)

Time (ms)


-60

-40

-20

0

20

40

450 500 550 600 650

Voltage(kV)

Time (ms)


-2

0

2

4

6

8

538 540 542 544 546 548 550 552

,

Current(kA)

Time (ms)


-400

-200

0

200

400

0 200 400 600 800

,

Voltage(kV)

Time (ms)



8/12/2019 46_TOV GIS SS

6/7

The value of COG is within the IEEE standard limits(IEEE Standard C62.92.1-2000) which are less than0.80

For the Case 7, voltages of the other 2 phases areclamped to certain value. This situation occurredbecause of the unloaded cable is de-energized. In suchcases, grounding of the two ends of the cable ismandatory while re-energizing.

The minimum distance between 220kV side oftransformer and 216kV surge arrester is found to be10.2m. The protective margin of transformer and surgearrester is found to be 20.3% and 42% respectively. Asthe distance between transformer and surge arrester is6m, the surge arrester can be placed anywhere in the 6mdistance. The safety margins are applicable only for theconnecting leads of surge arrester not exceeding 7m.

The minimum distance between 33kV side oftransformer and 30kV surge arrester is found to be5.6m. The protective margin of transformer and surgearrester is found to be 20.7% and 30% respectively. Asthe distance between transformer and surge arrester is20m, connected through cable, the surge arrester has to

be placed near the transformer terminals. The safetymargins are applicable only for the connecting leads ofsurge arrester not exceeding 2m.

The arrester spark over voltage indicates a definite andadequate margin of protection as compared to choppedwave (CWW) value of transformer. There is almostabsolute assurance that the front of wave (FOW)withstand value provide adequate margin of protectionwith the above mention lead lengths and separationdistances.

V. 216KVSURGE ARRESTER SEPARATION DISTANCE FROM220/33KVTRANSFORMER

The most effective location for any surge arrester is at the

terminals of the equipment to be protected. Locating a surgearrester remote from the equipment to be protected reduces theprotective margin. Depending on a number of factors, thetransient voltage at the equipment can easily be more thantwice the surge arrester protective level. An analysis has to bemade to determine how far a surge arrester can be located awayfrom the transformer and still provide adequate protection.

Fig. 17.Location of surge arrester on 220kV side

Our objective is to find the distance D between surgearrester and transformer

Input parameters:

System voltage: 220kVMaximum system voltage: 245kV (rms)Lightning impulse level (BIL): 1050kVpSurge propagation time (): 300m/usSurge impedance of transmission line: 450

Surge arrester rated voltage: 216kVMaximum continuous operating voltage (MCOV): 178kVMax. Residual Voltage at steep front Impulse (1/20us) at10kA peak (Va): 660kVpChopped wave withstand of transformer (CWW):1.1*BIL=1.1*1050=1155kVRate of rise of surge current (di/dt): 2S/Z

Conductor length between junction J and surge arresterterminals (d): 4mConductor length between surge arrester ground (d): 3mRate of rise of incoming surge at junction J (S): 11kV perkV MCOV (max of 2000kV/us)

Calculation:Rate of rise of incoming surge at junction J (S):11kV*178kV=1958kV/usRate of rise of surge current (di/dt): 2S/Z= (2*1958)/450=8.7kA/us

Inductance of surge arrester leads (uH): 1.3uH/mTotal length d= d+d=4+3= 7mTotal lead inductance: 1.3*7= 9.1uHVoltage across surge arrester from junction J to ground(Vsa): Va+ L*di/dt= 660+ (9.1*8.7) =739.17kV

(This does not necessarily appear simultaneously at thepeak value of arrester residual voltage. However this value ofL*di/dt (79.2kV) demonstrates the order of magnitude of

possible inductive voltage drop which can superimpose thearrester residual voltage.

Maximum stress allowable at the transformer (Vt)

Vt= CWW/1.15 (if time to crest value is less than 2us)Vt= BIL/1.15 (if time to crest value is greater than 2us)Time to crest value: Va/S= 660/1958 = 0.3us (less than 2us.So, use Vt= CWW/1.15)Vt= 1155/1.15= 1004.3kV

=

sa

t

V

V1004.3/739.17= 1.36

From Fig. 18 the x-axis representssaV

SD

*

*

and y-axis

representssa

t

V

V. Based on the ratio obtained above 36.1=

sa

t

V

V

the corresponding x value is 0.09.

'

21

220/33


8/12/2019 46_TOV GIS SS

7/7

The curve shown in Fig. 18, was generated from studiesusing the Electromagnetic Transients Program (EMTP).

09.0*

*=

saV

SD

(Solving this equation for distance D gives)

D=10.2m

Next step is to calculate the protective margin oftransformer and surge arrester

Protective margin of surge arrester= ((BIL-Vsa)/ Vsa)*100 =

42%

Protective margin of transformer= ((BIL-Vt)/ Vt)*100

For this we have to calculate the actual voltage available at

transformer terminals

/*2*)*( DSVV sat +=

is reflection coefficient at transformer terminals(assumed as 1) factor of 2 arises from the return length fromarrester to transformer

kVVt 3.872300/)2.10*2*1958(17.739 =+=

This gives the protective margin of transformer as 20.3%

Similar methodology is adopted for 33kV side of surgearrester.

Fig. 18.Curve for separation distance of surge arrester from transformer

VI. CONCLUSION

In this paper temporary overvoltages arising due toswitching and fault conditions are studied. Distributedcapacitance of cables plays a major role in overvoltages and isobserved while energizing the unloaded cables. The betterunderstanding of magnitude of overvoltages can be observedby analyzing the system without surge arresters. Care has to betaken while placing the arrester near transformer terminals andlength of connecting leads of surge arrester has to be taken intoconsideration.

ACKNOWLEDGMENT

The authors would like to thank Mr. Srinivas and Mr.Kondala Rao Bandaru of Crompton Greaves Ltd. for theirvaluable support.

REFERENCES

[1] IEEE Std C62.92.4-1991, IEEE Guide for the Application of Neutral

Grounding in Electrical Utility Systems, Part IVDistribution, IEEEPower & Energy Society.

[2] Math H. J. Bollen, Emmanouil Styvaktakis, Irene Yu-Hua Gu,Categorization and Analysis of Power System Transients, IEEE Trans.on Power Del., Vol. 20, No. 3, July 2005.

[3] George W. Walsh, A Review of Lightning Protection and GroundingPractices,IEEE Trans. on Ind. Appl., Vol. Ia-9, No. 2, Mar./Apr. 1973.

[4] D.W. Durbak, A.M. Gole, E.H. Camm, M.Marz, R.C. Degeneff, R.P.OLeary, R. Natarajan, J.A. Martinez-Velasco, Kai-Chung Lee, A.Morched, R. Shanahan, E.R. Pratico, G.C. Thomann, B. Shperling, A. J.F. Keri, D.A. Woodford, L. Rugeles, V. Rashkes, A. Sarshar,Guidelines for Switching Transients Report Prepared by the SwitchingModeling Transients Task Force of the IEEE Modeling and Analysis ofSystem Transients Working Group, Special publication modeling andsimulation working group 15.08.

[5] D.W. Durbak, A.M. Gole, E.H. Camm, M.Marz, R.C. Degeneff, R.P.OLeary, R. Natarajan, J.A. Martinez-Velasco, Kai-Chung Lee, A.

Morched, R. Shanahan, E.R. Pratico, G.C. Thomann, B. Shperling, A. J.F. Keri, D.A. Woodford, L. Rugeles, V. Rashkes, A. Sarshar,Guidelines for Switching Transients Report Prepared by the SwitchingModeling Transients Task Force of the IEEE Modeling and Analysis ofSystem Transients Working Group, Special publication modeling andsimulation working group 15.08.

[6] Babak Badrzadeh, Martin Hgdahl, Emir Isabegovic, Transients inWind Power Plants - Part I: Modeling Methodology and Validation,

IEEE Trans. on Ind. Appl., Vol. 48, Issue 2, Oct. 2011.

[7] Babak Badrzadeh, Martin Hgdahl, Nand Singh, Henrik Breder,Kailash Srivastava, Transients in Wind Power Plants - Part II: CaseStudies,IEEE Trans. on Ind. Appl., Oct. 2011.

[8] Abey D., Samson G., Analysis of Transients in Wind Parks: Modelingof System Components and Experimental Verification, MSc thesisChalmers University

[9] R. H. Harner, Rodriguez, Transient Recovery Voltages AssociatedWith Power-System, Three-Phase Transformer Secondary Faults, IEEE

Power Engineering Society, Vol PAS-91 Issue 5 Jan. 30-Feb. 4, 1972.[10] A. Morched, B. Gustavsen, M. Tartibi, A Universal Model for Accurate

Calculation of Electromagnetic Transients on Overhead Lines andUnderground Cables, IEEE Transactions on Power Delivery, Vol. 14,No. 3, pp. 1032-1038, July 1999.

[11] IEC 60071-4 (2004), Computational guide to insulation co-ordinationand modelling of electrical networks,

[12] IEEE Std C62.22-1997, IEEE Guide for the Application of Metal-Oxide Surge Arresters for Alternating-Current Systems, IEEE PowerEngineering Society

[13] Chennamadhavuni, A, Munji, K.K, Bhimasingu, R, Investigation oftransient and temporary overvoltages in a wind farm, IEEEInternational Conference on Power System Technology (POWERCON),Oct 2012.

[14] N. R. Watson, J. Arrillaga, Power Systems Electromagnetic TransientsSimulation, Institution of Electrical Engineers.

0.01 0.1 11

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

D*S/*Vsa

Vt/Vsa


46_TOV GIS SS

Documents

Transcript of 46_TOV GIS SS