p r 11 hydro p.o. box 12400. st. john's. ni hydro place ... · documentation would be supplied...

31
Ai\p r I newfoundland labrador 11 hydro a nalcor energy company Hydro Place. 500 Columbus Drive. P.O. Box 12400. St. John's. NI Canada A1B 4K7 t. 709.737.1400 f. 709.737.1800 www.n1h.nl.ca December 17, 2014 The Board of Commissioners of Public Utilities Prince Charles Building 120 Torbay Road, P.O. Box 21040 St. John's, Newfoundland & Labrador A1A 5B2 Attention: Ms. Cheryl Blundon Director Corporate Services & Board Secretary Dear Ms. Blundon: Re: Newfoundland and Labrador Hydro - the Board's Investigation and Hearing into Supply Issues and Power Outages on the Island Interconnected System: Supplementary Response in Relation to PUB-NLH-457 and PUB-NLH-458 In its responses to the Board's RFIs PUB-NLH-457 and PUB-NLH-458, Hydro indicated that additional documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed the original and 12 copies of the following: a) Hydro's analysis of the impact of transmission line contingencies on system losses related to alternate generation dispatches (re: PUB-NLH-457); and, b) Two reports by Trans Grid Solutions Inc. related to the simulation of the Sunnyside Ti failure and an investigation of the Western Avalon T5 transformer failure concerning whether or not harmonics or system resonance were contributing factors to the system events of January, 2014 (re: PUB-NLH-458). We trust the foregoing is satisfactory. If you have any questions or comments, please contact the undersigned. Yours truly, NEWFOUNDLAND AND LABRADOR HYDRO Tracey UPennell Legal Counsel TLP/jc cc: Gerard Hayes — Newfoundland Power Thomas Johnson — Consumer Advocate Paul Coxworthy — Stewart McKelvey Stirling Scales Danny Dumaresque ecc: Roberta Frampton Benefiel — Grand Riverkeeper Labrador

Upload: others

Post on 24-Mar-2020

1 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Ai\p r I newfoundland labrador

11 hydro a nalcor energy company

Hydro Place. 500 Columbus Drive.

P.O. Box 12400. St. John's. NI

Canada A1B 4K7

t. 709.737.1400 f. 709.737.1800

www.n1h.nl.ca

December 17, 2014

The Board of Commissioners of Public Utilities

Prince Charles Building

120 Torbay Road, P.O. Box 21040

St. John's, Newfoundland & Labrador

A1A 5B2

Attention: Ms. Cheryl Blundon

Director Corporate Services & Board Secretary

Dear Ms. Blundon:

Re: Newfoundland and Labrador Hydro - the Board's Investigation and Hearing into Supply Issues and Power Outages on the Island Interconnected System: Supplementary Response in Relation to PUB-NLH-457 and PUB-NLH-458

In its responses to the Board's RFIs PUB-NLH-457 and PUB-NLH-458, Hydro indicated that additional

documentation would be supplied to the Board when the related work was completed. In this regard,

please find enclosed the original and 12 copies of the following:

a) Hydro's analysis of the impact of transmission line contingencies on system losses related to

alternate generation dispatches (re: PUB-NLH-457); and,

b) Two reports by Trans Grid Solutions Inc. related to the simulation of the Sunnyside Ti failure and

an investigation of the Western Avalon T5 transformer failure concerning whether or not

harmonics or system resonance were contributing factors to the system events of January, 2014

(re: PUB-NLH-458).

We trust the foregoing is satisfactory. If you have any questions or comments, please contact the

undersigned.

Yours truly,

NEWFOUNDLAND AND LABRADOR HYDRO

Tracey UPennell

Legal Counsel

TLP/jc

cc: Gerard Hayes — Newfoundland Power

Thomas Johnson — Consumer Advocate Paul Coxworthy — Stewart McKelvey Stirling Scales

Danny Dumaresque

ecc: Roberta Frampton Benefiel — Grand Riverkeeper Labrador

Page 2: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

     

 

                                

 

 

Engineering Support Services for: 

 

Sunnyside Transformer T1 Fire  

Newfoundland and Labrador Hydro 

 

   

Attention:  

Mr. Peter Thomas 

 

 

Report R1335.01.00 

PSCAD Investigation of the Sunnyside T1 Transformer Failure 

 

Prepared by: 

TransGrid Solutions Inc. 200 – 150 Innovation Dr. 

Winnipeg, MB R3T 2E1 

CANADA 

 

www.transgridsolutions.com 

 

    Oct 5th, 2014 

 

Reference: PUB-NLH-458 Atth 2

Page 3: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

Disclaimer 

This report was prepared by TransGrid Solutions Inc. (“TGS”), whose responsibility is limited to the scope of work 

as shown herein. TGS disclaims responsibility for the work of others incorporated or referenced herein. This report 

has been prepared exclusively for Newfoundland and Labrador Hydro and the project identified herein and must 

not be reused or modified without the prior written authorization of TGS. 

Revisions 

Project Name:  Sunnyside Transformer T1 Fire 

Document 

Title: 

PSCAD Investigation of the Sunnyside T1 Transformer Failure 

Document 

Type: 

Draft report 

Document No.:  R1335.01.00 

Last Action 

Date: 

Oct 5th, 2014 

           

Rev. 

No. 

Status  Prepared By  Checked By  Date  Comments 

00  IFC  D. Kell  R. Kolt  05/10/14   

01           

           

           

           

 

Legend of Document Status: 

Approved by Client   ABC   

Draft for Comments  DFC   

Issued for Comments  IFC   

Issued for Approval  IFA   

Issued for Information   IFI   

Returned for Correction  RFC   

Approval not Required  ANR   

   

Reference: PUB-NLH-458 Atth 2

Page 4: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 2                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

Table of Contents 

1.  Introduction .............................................................................................................................................. 3 2.  PSCAD Model Development ....................................................................................................................... 5 

2.1  AC System model ......................................................................................................................................... 5 

2.2  AC Transmission Lines .................................................................................................................................. 7 

2.3  Power Transformers ..................................................................................................................................... 9 

2.4  T5 Transformer at Sunny Side and T1 Transformer at Western Avalon .................................................... 10 

2.5  PSCAD Model Benchmarking Against PSS/E............................................................................................... 12 

3.  Modeling of Fault...................................................................................................................................... 14 

3.1  Transformer Fault ...................................................................................................................................... 14 

4.  Results ...................................................................................................................................................... 15 5.  Conclusions and Recommendations .......................................................................................................... 19 

 

List of Figures Figure 1‐1 Example of Low resolution waveforms ........................................................................................................ 3 

Figure 2‐1 SLD of Newfoundland System ...................................................................................................................... 6 

Figure 2‐2 Example Line Layout ..................................................................................................................................... 8 

Figure 2‐3 Detailed Line Model ..................................................................................................................................... 9 

Figure 2‐4 T1 ‐ SSD T5 ‐ WAV ....................................................................................................................................... 10 

Figure 2‐5 Sunny Side T1 transformer model .............................................................................................................. 11 

Figure 2‐6 SSD T1 Parameters ..................................................................................................................................... 12 

Figure 4‐1 PSCAD Simulation ....................................................................................................................................... 15 

Figure 4‐2 Actual Event ................................................................................................................................................ 15 

Figure 4‐3 Transformer Currents ................................................................................................................................. 16 

Figure 4‐4 Harmonics of Transformer (RMS) ............................................................................................................... 17 

Figure 4‐5 Bay D'Espoir and TL237 measurements ..................................................................................................... 18 

 

List of Tables 

Table 2‐1 Frequency Dependent AC lines ...................................................................................................................... 7 

Table 2‐2 SSD T5 ‐ WAV ............................................................................................................................................... 10 

Table 2‐3 SCL Comparison ........................................................................................................................................... 12 

Table 2‐4 Positive Sequence Impedance Comparison ................................................................................................. 13 

Table 2‐5 Loadflow Comparison .................................................................................................................................. 13 

Table 3‐1 AC system Fault Sequence ........................................................................................................................... 14 

Table 3‐2 Internal Transformer Fault Sequence .......................................................................................................... 14 

 

Reference: PUB-NLH-458 Atth 2

Page 5: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 3                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

1. Introduction 

This report presents the findings of the PSCAD simulation trying to recreate the Newfoundland T1 transformer 

fault that occurred at 9:05am on January 4th, 2014. 

The original scope of the project was to model the fault based on delivered comtrade data which records the 

pertinent waveforms. Upon receipt of the data, the following was noticed: 

1. The comtrade data delivered for times: 

04/01/2014,13:13:09.000260 

04/01/2014,10:05:34.000260 

Both of which did not match the time of the fault. The comtrade data which had the same time stamp as the 

fault was delivered as a pdf file, which is included in Appendix A. 

2. The comtrade data had a very low resolution as shown in Figure 1‐1, which made it very hard to match to the 

PSCAD simulation. 

 

Figure 1-1 Example of Low resolution Waveforms  

APSCAD model was created on the following information in order to try and recreate the fault based on the pdf 

comtrade file. 

2014Base‐Peak for Dyr.sav 

PSS/E data file which represents the Newfoundland System conditions prior to the fault 

Peak Case.dyr 

PSS/E dynamics file 

SSDTS T1 transformer nameplate, test data and transformer data (delivered as pdf files) 

WAVTS T5 transformer nameplate, test data and transformer data (delivered as pdf files) 

-100

-50

0

50

100

10 15 20 25 30

SSTSCF1C>1_A-230 KV TL202 A Phase Voltage(V)

Electrotek Concepts® TOP, The Output Processor®

Magnitude (

Mag

)

Time (ms)

Reference: PUB-NLH-458 Atth 2

Page 6: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 4                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

AC Line geometric data based on past work performed by TGS. This included mutual coupling of 

the lines the shared the same right‐of‐way. 

AMEC report “Newfoundland and Labrador Hydro Transmission Availability” March 21, 2014. 

This report gave the details of the sequence of events during the fault on January 4th. 

 

Reference: PUB-NLH-458 Atth 2

Page 7: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 5                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

2. PSCAD Model Development 

2.1 AC System model 

The following files provided by Newfoundland and Labrador Hydro (NLH) and were used as the base case to 

develop the equivalent PSCAD model: 

2014Base‐Peak for Dyr.sav 

Peak Case. Dyr 

The equivalent ac system in PSSE was converted to PSCAD.  Since this study deals with a transient phenomenon as 

a result of transformer failure at Sunnyside, the representation of the power system components with more 

accuracy at higher frequencies than the fundamental frequency is crucial for a better analysis of the event. 

Therefore the following changes were made to the converted case: 

All the generators were represented with their associated dynamic data. That includes also  

exciter, governor and power system stabilizers models (PSS)  

A majority of the transmission lines surrounding the Sunnyside and Western Avalon  were 

modeled with frequency dependent line models according to the tower geometries and 

conductor configurations 

T1 transformer at Sunnyside and T5 transformer at Western Avalon based on the latest data 

provided by NLH 

Figure 2‐1 shows the single line diagram of the ac system used in this study. Please note that the whole case is not 

shown in the diagram and only the main portion of the ac system surrounding Sunnyside and Western Avalon is 

shown. 

 

 

Reference: PUB-NLH-458 Atth 2

Page 8: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 6                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

 

Figure 2-1 SLD of Newfoundland System

Reference: PUB-NLH-458 Atth 2

Page 9: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 7                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

2.2 AC Transmission Lines 

The major transmission line models in the PSCAD case which when originally converted from PSS/E, were 

represented as pi‐sections and Bergeron line models   

The Bergeron and pi‐section line representations are only adequate for studies that essentially require the correct 

fundamental frequency impedance. However, in order to get a higher degree of accuracy, some of the lines near 

the affected buses were replaced with frequency dependent line models. 

Table 2‐1 lists of the lines that were modeled as frequency dependent lines. 

Table 2-1 Frequency Dependent AC lines

From Bus#  To Bus#  From Bus#  To Bus# 

195229  195230  195167  195169 

195222  195227  195169  195171 

195221  195216  195171  195173 

195216  195215  195173  195175 

195221  195220  195222  195229 

195220  195218  195227  195229 

195215  195208  195229  195236 

195215  195205  195229  195234 

195205  195536  195234  195236 

195205  195208  195236  195238 

195622  195625  195221  195222 

195625  195627  195152  195153 

195124  195122  195153  195154 

195122  195120  195155  195157 

195120  195115  195157  195159 

195115  195112  195152  195159 

195112  195111  195620  195620 

195209  195210  195621  195622 

195208  195209  195112  195113 

195205  195206  195600  196500 

195500  195620  ‐  ‐ 

Reference: PUB-NLH-458 Atth 2

Page 10: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 8                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

Figure 2‐2 shows an example of one of the more complicated line layouts, which includes the mutual coupling of 

lines TL201, TL242 and TL218 and the mutual coupling of lines TL201 and TL217. Figure 2‐3 shows the detailed line 

model for the lines TL201, TL242 and TL218. 

 

Figure 2-2 Example Line Layout

N1

N2

N3

236

229

N4

234

238

SECTIO

NPI

2 CIRCUIT

1.0e-3 [ohm]

TL_201_218_242_1

TL201

TL242

TL_201_218_242_1

1

TL218

TL201

TL242

TL_201_218_242_1

1

TL218

1.0e-3 [ohm]

1.0e-3 [ohm]

TL_2490_229_1_1

1.0e-3 [ohm]

1.0e-3 [ohm]

1.0e-3 [ohm]

1.0e-3 [ohm]

TL201/T

L217

COU

PLED

PISECT

ION

COU

PLED

PISECT

ION

COU

PLED

PISECT

ION

1.0e-3 [ohm]

P = 260.6

Q =

12.79

V A

P = 166.1

Q =

-33.09

V A

P = 113.5

Q =

-59.98

V A

P = -185.2

Q =

-61.51

V A

P = -205.7

Q =

-68.45

V A

P = 111.8

Q =

-59.01

V A

P = 105.2

Q =

5.469

V A

P = 183.8

Q =

55.21

V A

==

=T

l218

==

=T

l242

==

=T

l217

P = -162

Q =

43.28

V A

==

=SZ

==

=SZ

==

=SZ

Reference: PUB-NLH-458 Atth 2

Page 11: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 9                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

 

 

Figure 2-3 Detailed Line Model  

2.3 Power Transformers 

The power transformer models T5 at Sunny Side and T1 at Western Avalon are updated based on the following 

data files received from NLH: 

“WAVTS T5 nameplate.pdf” 

“WAVTS T5 Test Report.pdf” 

“Western Avalon‐T5.pdf” 

“Sunnyside‐T1.pdf” 

“SSDTS T1 Nameplate.pdf” 

“SSDTS T1 test report.pdf” 

2000.0 [ohm*m]Resistivity:

Analytical Approximation (Wedepohl)Analytical Approximation (Deri-Semlyen)Aerial:

Underground:Mutual: Analytical Approximation (LUCCA)

20Max. Order per Delay Grp. for Prop. Func.:

20Maximum Order of Fitting for Yc:

1.0E6 [Hz]Curve Fitting End Frequency:Curve Fitting Starting Frequency: 0.5 [Hz]

Frequency Dependent (Phase) Model Options

Maximum Fitt ing Error for Yc: 1.0 [%]

1.0 [%]Maximum Fitt ing Error for Prop. Func.:

Travel Time Interpolation:

100Total Number of Frequency Increments:

On

DisabledDC Correction:Passivity Checking: Disabled

12.57 [m]

6.7056 [m]

C1 C2 C3

Conductors: Grosbeak

Tower: TL201

0 [m]

G1

5 [m]

Ground_Wires: 1/2"HighStrengthSteel

21.6834 [m]

6.858 [m]

C4 C5 C6

Conductors: 804

Tower: TL242

-35.847 [m]

G1

5 [m]

Ground_Wires: 1/2"HighStrengthSteel 13.53 [m]

5.18 [m]

C7 C8 C9

Conductors: Plover

Tower: TL218

31.27 [m]

G1

5 [m]

Ground_Wires: 1/2"HighStrengthSteel

Reference: PUB-NLH-458 Atth 2

Page 12: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 10                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

2.4 T5 Transformer at Sunny Side and T1 Transformer at Western Avalon 

The T5 transformer at Sunnyside and the T1 transformer at Western Avalon is modeled based on the data 

provided by NLH.  Figure 2‐4 shows the PSCAD mode and Table 2‐2 shows the data used to model the 

transformers. 

 

Figure 2-4 T1 - SSD T5 – WAV  

Table 2-2 SSD T5 - WAV

Name  Tmva  f  YD1  YD2  YD3 

T5  75 [MVA]  60.0 [Hz]  Y  Delta  Y 

T1  75.0 [MVA]  60.0 [Hz]  Y  Delta  Y 

Name  Lead  Xl12  Xl13  Xl23  Ideal 

T5  Lags  0.1796 [pu]  0.0563 [pu]  0.1347[pu]  Yes 

T1  Lags  0.19677 [pu]  0.05578 

[pu] 

0.11371 [pu]  Yes 

Name  NLL  CuL  Tap  V1  V2 

T5  0.000533 [pu]  0.00123335[pu]  #1  230.0 [kV]  6.9 

[kV] 

T1  0.00057867 [pu]  0.00149133 [pu]  #1  230 [kV]  6.9 

[kV] 

Name  V3  Enab  Sat  Hys   

T5  138.0 [kV]  Yes  Middle  Jiles_Atherton   

T1  138 [kV]  Yes  Middle  Jiles_Atherton   

1.0e6 [ohm]

#1

75 [MVA]230.0 [kV]/6.9 [kV]/138.0 [kV]

#3

#21.0e6 [ohm]

1.0e6 [ohm]

0.95

0.9625

1e-3 [ohm]

mid delta tert iary w inding is grounded. refer to xfr name plate

InT4_HInT4_L

#1

75.0 [MVA]230 [kV]/6.9 [kV]/138 [kV]

#3

#2

Reference: PUB-NLH-458 Atth 2

Page 13: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 11                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

2.4.1.1 Sunny side Transformer Model Internal Fault Modeling 

The T1 transformer model was modeled such that various internal faults can be applied to the transformer. Figure 

2‐5 shows the T1 transformer model that was used to investigate a failure of the a‐phase winding to ground (short 

to the tank) and a failure between the windings. Figure 2‐6 shows the SSD T1 parameters. 

 

Figure 2-5 Sunny Side T1 Transformer Model  

 

  

 

 

 

 

 

#2

#3

Tap

#1

A

B

C

N

B

A

C

N

N3

N1

Tap

G1G2

N2

Tap

Tap

Tap

#2

#3

Tap

#1

#2

#3

Tap

#1

Faulta1

+

R1

Ia

Ib

Ic #2

#3

Tap

#1

+

R1Faulta

Reference: PUB-NLH-458 Atth 2

Page 14: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 12                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

 

Figure 2-6 SSD T1 Parameters

2.5 PSCAD Model Benchmarking Against PSS/E 

Upon development of the ac network in PSCAD based on the equivalent developed model in PSS/E, it is required to 

validate the PSCAD case against the equivalent case in PSSE.  The validation was performed through comparison of 

the short circuit levels at certain buses and the results of the load flow and power transfer at some selected 

transmission lines. 

The results of the comparison are shown in Table 2‐3, Table 2‐4 and Table 2‐5. The results compare very well 

Table 2-3 SCL Comparison

 

Bus 

 

Bus 

Number 

SCL (MVA)   

% difference PSS/E Equivalent  PSCAD 

Western Avalon  195229  1997.30  1996.23  0.05 

Sunny side  195222  2520.80  2469.65  2.03 

Bay D Espoir  195221  2058.97  2014.47  2.16 

Hollyrood  195234  2052.30  1998.49  2.62 

Stony Brook  195216  3738.80  3601.09  3.68 

Oxen Pond  195238  2164.00  2088.43  3.49 

 

 

 

 

Reference: PUB-NLH-458 Atth 2

Page 15: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 13                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

Table 2-4 Positive Sequence Impedance Comparison

Bus Bus 

Number 

Positive Impedance magnitude 

Z+(Ohm) 

Positive Impedance angle  

Z+(degree) 

PSS/E 

Equivalent 

PSCAD  % 

difference 

PSS/E 

Equivalent 

PSCAD  % 

difference 

Western Avalon  195229  26.75  26.5  0.93  66.83  66.52  0.46 

Sunnyside  195222  21.62  21.42  0.93  70.4  70.23  0.24 

Bay D Espoir  195221  26.51  26.26  0.94  69.71  69.79  ‐0.11 

Hollyrood  195234  26.8  26.47  1.23  70.87  70.98  ‐0.16 

Stony Brook  195216  14.79  14.69  0.68  82.73  82.66  0.08 

Oxen Pond  195238  25.39  25.33  0.24  78.77  78.68  0.11 

 

Table 2-5 Loadflow Comparison

From 

Bus 

Number 

To Bus 

Number 

Line  Real Power (MW)  Reactive Power (MVAR) 

PSS/E 

Equivalent 

PSCAD  % 

difference 

PSS/E 

Equivalent 

PSCAD  % 

difference 

195229  195234  TL217  109.5  113.1  ‐3.29%  ‐60.5  ‐59.72  1.29% 

195236  TL201  165.7  166.2  ‐0.30%  ‐33.4  ‐33.06  1.02% 

195222  TL203  ‐213.8  ‐216.3  ‐1.17%  56.8  56.1  1.23% 

195227  TL237  ‐184.8  187.2  ‐1.30%  31  30.19  2.61% 

195222  195227  TL207  214.1  217.1  ‐1.40%  ‐110.2  ‐109.3  0.82% 

195221  TL206  ‐272.0  ‐275.8  ‐1.40%  54.9  53.58  2.40% 

195221  TL202  ‐273.3  ‐275.8  ‐0.91%  56  53.59  4.30% 

195221  195216  TL204  57.4  55.28  3.69%  ‐5.0  ‐5.3  ‐6.00% 

195216  TL231  57.6  55.28  4.03%  ‐5.0  ‐5.3  ‐6.00% 

195220  TL234  ‐115  ‐114.6  0.35%  ‐15.9  ‐16.68  ‐4.91% 

 

Reference: PUB-NLH-458 Atth 2

Page 16: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 14                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

3. Modeling of Fault 

The modeling of the fault sequence was based on the AMEC report “Newfoundland and Labrador Hydro 

Transmission Availability” March 21, 2014. The detailed sequence of events was given as shown Table 3‐1 below: 

Table 3-1 AC System Fault Sequence Time  delta‐T  PSCAD Time  event  PSCAD Breaker Label 

9:05:34.6    3.1  

Fault  Please see section 3.1

9:05:34.715  0.115  3.215  138kV Breaker L109T4 at SSD Opens CB1 

9:05:34.753  0.038  3.253  138kV Breaker B3T4 at SSD Opens  CB11 

9:05:34.755  0.002  3.255  230kV Breaker B1L02 at SSD Opens  CB2 

9:05:34.786  0.031  3.286  138kV Breaker B2T1 at SSD Opens  CB3 

4 of 5 breakers for T1 now open, B1L03 does not open 

9:05:36.719  1.933  5.219  Breaker L03L06 at SSD opens  CB5 

  5.219  Breaker B1B2 at CBC Opens  CB5 

9:05:36.742  0.023  5.242  Breaker L03L06 at SSD opens  CB6 

9:05:36.820  0.078  5.32  Breaker L03L17 at WAV opens  CB7 

9:05:36.991  0.171  5.91  Breaker L01L03 at WAV opens  CB8 

 

3.1 Transformer Fault 

In addition to the fault sequence modeled above, internal faults on the transformer were modeled. After various 

faults were applied, Table 3‐2 shows the internal fault sequence that was found to give the closest results to the 

transformer fault. 

Table 3-2 Internal Transformer Fault Sequence PSCAD Time 

event 

3.1  

Fault applied between phase A 230kV and 138 kV windings with a resistance of 50 ohms 

3.15  Internal winding fault evolves into a 230kV to ground fault with a resistance of 50 ohms 

3.2  Fault resistance decreases from 50 ohms to 25 ohms 

4.0  A‐phase to ground fault evolves to a 3‐phase to ground fault with a resistance of 50 ohms

4.2  Resistance of 3‐phase faults decreases from 50 ohms to 25 ohms 

4.7  Resistance of 3‐phase faults decreases from 50 ohms to 10 ohms 

 

Reference: PUB-NLH-458 Atth 2

Page 17: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 15                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

4. Results 

Appendix 2 shows the results for the fault. As it is unknown if this is the actual fault that was experienced by the 

transformer, comparing values would not be useful. Of more use is comparing the trend. What is obvious right 

away is that as breaker B1L03 did not open, the fault on the transformer was being sustained as shown in Figure 

4‐1. Referring to Figure 4‐2, the neutral current in T1 extinguished before the breakers cleared the fault. Based on 

the simulations, it seems more likely that the CT or the cabling was damaged during the event which led to a loss 

of measurement. 

 

Figure 4-1 PSCAD Simulation  

 

Figure 4-2 Actual Event  

Figure 4‐3shows the currents in the actual windings of the failed transformer during the fault. 

Figure 4‐4shows the harmonics spectrum in the transformer during the fault. 

x 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

y

T1 High side Neutral Current

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

y

T4 High side Neutral Current

Reference: PUB-NLH-458 Atth 2

Page 18: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 16                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

 

Figure 4-3 Transformer Currents  

x 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75

-1.25

1.25

y

Phase A 230kV Winding Current

-15.0 -10.0 -5.0 0.0 5.0

10.0 15.0

y

Phase A 6.9kV Winding Current

-1.50 -1.00 -0.50 0.00 0.50 1.00 1.50

y

Phase A 138kV Winding Current

-0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60

y

Phase B 230kV Winding Current

-15.0 -10.0 -5.0 0.0 5.0

10.0 15.0

y

Phase B 6.9kV Winding Current

-0.60 -0.40 -0.20 0.00 0.20 0.40 0.60

y

Phase B 138kV Winding Current

-0.50

0.50

y

Phase C 230kV Winding Current

-15.0 -10.0 -5.0 0.0 5.0

10.0 15.0

y

Phase V 6.9kV Winding Current

-0 80-0.60 -0.40 -0.20 0.00 0.20 0.40 0.60

y

Phase C 138kV Winding Current

Reference: PUB-NLH-458 Atth 2

Page 19: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 17                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

 

Figure 4-4 Harmonics of Transformer (RMS)

Reference: PUB-NLH-458 Atth 2

Page 20: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 18                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

Figure 4‐5 shows the P, Q and speed of the Bay D’Espoir unit 1 and the current in line TL237 and the Western 

Avalon bus voltage. As indicated in the AMEC report, and confirmed here, the ac system starts to go unstable for 

this fault. 

 

Figure 4-5 Bay D'Espoir and TL237 measurements  

G_195001_0_1_DYR,Measure,P2 : Graphs

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

0.990

1.000

1.010

1.020

1.030

1.040

1.050

1.060

(pu

)

Wpu

-20

0

20

40

60

80

100

(M

W)

P

-60 -40 -20

0 20 40 60 80

100

(M

VAR)

Q

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

I237

-250 -200 -150 -100 -50

0 50

100 150 200 250

V_WA

Reference: PUB-NLH-458 Atth 2

Page 21: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 19                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

5. Conclusions and Recommendations 

Although the exact fault has not been reproduced here, a fairly comparable one has been simulated. It is evident 

that due to the long duration it took to clear the transformer fault, the transformer experienced very high 

currents, with nearly 2.5kA flowing for the duration of the fault. 

TGS recommendeds that once more details are available about the actual fault of the transformer, that the model 

be updated and simulations rerun to recreate what happened. This new information will give further confidence in 

the developed model and allow for future studies to be done either as a system strengthening exercise or for a 

post‐mortem on future faults. 

Reference: PUB-NLH-458 Atth 2

Page 22: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 20                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

6. Appendix 1 – Actual TFR Traces 

 

 

 

Reference: PUB-NLH-458 Atth 2

Page 23: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Transcan DFR : SUNNYSIDE Terminal Station SSTSCF1C.X0V Jan/04/2014 09:05:34 (file)All Channels - 0X, 3840Hz Page 1 of 2

0.000 ms 1791.667 ms

202-Va202-Vb202-Vc202-Ia202-Ib202-Ic202-In203-Va203-Vb203-Vc203-Ia203-Ib203-Ic203-InT1-InT4-In206-Va206-Vb206-Vc206-Ia206-Ib206-Ic206-In207-Va207-Vb207-Vc207-Ia207-Ib207-IcB2-VaB2-VbB2-Vc94T186T1203-94A1203-94B1203-94C1203-94L1203-94L2203-P1P2

Reference: PUB-NLH-458 Atth 2

Page 24: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Transcan DFR : SUNNYSIDE Terminal Station SSTSCF1C.X0V Jan/04/2014 09:05:34 (file)All Channels - 0X, 3840Hz Page 2 of 2

Trace Label Name Scale Units/Division1 202-Va 230 KV TL202 A Phase Voltage 1.00 72177.652 V2 202-Vb 230 KV TL202 B Phase Voltage 1.00 72458.470 V3 202-Vc 230 KV TL202 C Phase Voltage 1.00 72601.507 V4 202-Ia TL202 A Phase Current 5.00 338.114 A5 202-Ib TL202 B Phase Current 5.00 338.290 A6 202-Ic TL202 C Phase Current 5.00 339.371 A7 202-In TL202 Neutral Current 15.00 113.019 A8 203-Va 230 KV TL203 A Phase Voltage 1.00 72423.934 V9 203-Vb 230 KV TL203 B Phase Voltage 1.00 72506.562 V

10 203-Vc 230 KV TL203 C Phase Voltage 1.00 72394.188 V11 203-Ia TL203 A Phase Current 5.00 337.960 A12 203-Ib TL203 B Phase Current 5.00 338.712 A13 203-Ic TL203 C Phase Current 5.00 338.641 A14 203-In TL203 Neutral Current 15.00 112.692 A15 T1-In T1 Neutral Current 2.00 1059.220 A16 T4-In T4 Neutral Current 2.00 1059.457 A17 206-Va 230KV TL206 A Phase Voltage 1.00 72296.314 V18 206-Vb 230KV TL206 B Phase Voltage 1.00 72600.926 V19 206-Vc 230KV TL206 C Phase Voltage 1.00 72753.172 V20 206-Ia TL206 A Phase Current 5.00 339.398 A21 206-Ib TL206 B Phase Current 5.00 338.909 A22 206-Ic TL206 C Phase Current 5.00 338.978 A23 206-In TL206 Neutral Current 15.00 113.283 A24 207-Va 230KV TL207 A Phase Voltage 1.00 72562.495 V25 207-Vb 230KV TL207 B Phase Voltage 1.00 72516.289 V26 207-Vc 230KV TL207 C Phase Voltage 1.00 72466.927 V27 207-Ia TL207 A Phase Current 5.00 339.563 A28 207-Ib TL207 B Phase Current 5.00 338.912 A29 207-Ic TL207 C Phase Current 5.00 340.012 A30 B2-Va 138 KV B2 A Phase Voltage 1.00 43573.561 V31 B2-Vb 138 KV B2 B Phase Voltage 1.00 43518.666 V32 B2-Vc 138 KV B2 C Phase Voltage 1.00 43444.008 V33 94T1 94T1 N/A N/A34 86T1 86T1(NC) N/A N/A35 203-94A1 TL203 94A1X N/A N/A36 203-94B1 TL203 94B1X N/A N/A37 203-94C1 TL203 94C1X N/A N/A38 203-94L1 TL203 94L1 N/A N/A39 203-94L2 TL203 94L2 N/A N/A40 203-P1P2 TL203 21P1/P2 N/A N/A

Reference: PUB-NLH-458 Atth 2

Page 25: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Newfoundland and Labrador Hydro Sunnyside Transformer T1 Fire 

PSCAD Investigation of the Sunnyside T1 Transformer Failure   

R1335.01.00 21                                                                                                    Oct 5th, 2014 

© TransGrid Solutions Inc, 2014 

7. Appendix 2 – Simulated Traces 

Reference: PUB-NLH-458 Atth 2

Page 26: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Analog Graph

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

-300

-200

-100

0

100

200

300 y

V202:1

-500 -400 -300 -200 -100

0 100 200 300 400

y

V202:2

-400 -300 -200 -100

0 100 200 300 400

y

V202:3

-2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 2.50

y

I202:1

-2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00 2.50

y

I202:2

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

y

I202:3

-200 -150 -100

-50 0

50 100 150 200

y

V203:1

-250 -200 -150 -100

-50 0

50 100 150 200 250

y

V203:2

-200 -150 -100

-50 0

50 100 150 200

y

V203:3

Reference: PUB-NLH-458 Atth 2

Page 27: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Analog Graph

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

-4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0

yI203:1

-3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0

y

I203:2

-3.0 -2.0 -1.0

0.0 1.0 2.0 3.0

y

I203:3

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

T1 High side Neutral Current

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

T4 High side Neutral Current

-300 -200 -100

0 100 200 300

y

V206:1

-500

400

y

V206:2

-400 -300 -200 -100

0 100 200 300 400

y

V206:3

-2.50

2.50

y

I206:1

-2.50

2.50

y

I206:2

-3.0 -2.0 -1.0 0.0 1.0 2.0 3.0

y

I206:3

Reference: PUB-NLH-458 Atth 2

Page 28: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Analog Graph

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

-300

-200

-100

0

100

200

300 y

V207:1

-500 -400 -300 -200 -100

0 100 200 300 400

y

V207:2

-400 -300 -200 -100

0 100 200 300 400

y

V207:3

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

I207:1

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

I207:2

-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00

y

I207:3

-5.0 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0

y

SSD T1 phase A

-5.0 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0

y

SSD T1 phase B

-5.0 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0

y

SSD T1 phase C

Reference: PUB-NLH-458 Atth 2

Page 29: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

x 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75

-1.25 -1.00 -0.75 -0.50 -0.25 0.00 0.25 0.50 0.75 1.00 1.25

yPhase A 230kV Winding Current

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

y

Phase A 6.9kV Winding Current

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

y

Phase A 138kV Winding Current

-0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60

y

Phase B 230kV Winding Current

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

y

Phase B 6.9kV Winding Current

-0.60

-0.40

-0.20

0.00

0.20

0.40

0.60

y

Phase B 138kV Winding Current

-0.50 -0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40

y

Phase C 230kV Winding Current

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

y

Phase V 6.9kV Winding Current

-0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60

y

Phase C 138kV Winding Current

Reference: PUB-NLH-458 Atth 2

Page 30: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Analog Graph

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

-0.06m

-0.04m

-0.02m

0.00

0.02m

0.04m

0.06my

Imaga

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

y

Fluxa

-0.35m

-0.30m

-0.25m

-0.20m

-0.15m

-0.10m

-0.05m

0.00

0.05m

0.10m

0.15m

y

Imagb

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

y

Fluxb

-0.3m

-0.2m

-0.1m

0.0

0.1m

0.2m

0.3m

y

Imagc

-2.00

-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

y

Fluxc

Reference: PUB-NLH-458 Atth 2

Page 31: p r 11 hydro P.O. Box 12400. St. John's. NI Hydro Place ... · documentation would be supplied to the Board when the related work was completed. In this regard, please find enclosed

Analog Graph

x 0.00 0.50 1.00 1.50 2.00 2.50 3.00

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50

yIT1_H_FFTa:1

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70

y

IT1_H_FFTa:2

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400

y

IT1_H_FFTa:3

0.000

0.050

0.100

0.150

0.200

y

IT1_H_FFTa:4

0.000

0.050

0.100

0.150

0.200

y

IT1_H_FFTa:5

0.000 0.025 0.050 0.075 0.100 0.125 0.150 0.175 0.200

y

IT1_H_FFTa:6

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140

y

IT1_H_FFTa:7

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140

y

IT1_H_FFTa:8

0.000

0.020

0.040

0.060

0.080

0.100

y

IT1_H_FFTa:9

0.000

0.020

0.040

0.060

0.080

0.100

y

IT1_H_FFTb:10

Reference: PUB-NLH-458 Atth 2