SUMMARY

1. CLASSIFICATION OF SHORT DURATION FAULTS (VOLTAGE SAGS) IN TRANSMISSION AND DISTRIBUTION POWER SYSTEMS David Llanos Joaquim Meléndez Joan Colomer Juan Mora Magda Ruiz Javier Corbella Jorge Sánchez

2. X(Voltage Sag) x1: Sag duration x2: Sag magnitude 0 xn: Recovery slope Voltage sags Classification Descriptors abstraction Sag Class Fault location H1 C 1 Transmission Transmission H 2 C 2 Distribution H 3 C 4 H 4 Transmission C 7 Distribution H 5 C 3 SUMMARY

3. CONTENTS • Voltage Sag Definition • Significant Information of Voltage Sags • Classification Method • Classification Results • Conclusions • Future Work

4. VOLTAGE SAG DEFINITION A voltage magnitude event with a magnitude between 10% and 90% of the nominal rms voltage and duration between 0.5 cycles and one minute. [IEEE Std. 1159].

5. SIGNIFICANT INFORMATION OF VOLTAGE SAGS (I) Existing methods to characterise voltage sag use: • The lowest of the three-phase voltages • The longest duration In this work, significant proposed descriptors have been divided in: • Three-phase temporal descriptors • Single-phase temporal descriptors • Characterisation of faults based on symmetrical components

6. Vrms [p.u.] Three phase sag duration 1.0 0.9 Three phase sag magnitude Va Vb Vc Time SIGNIFICANT INFORMATION OF VOLTAGE SAGS (II) Definition-Three phase voltage sag descriptors

7. SIGNIFICANT INFORMATION OF VOLTAGE SAGS (III) Definition-Single phase voltage sags descriptors Vrms [p.u.] 1.0 Voltage recovery slope Voltage fall slope 0.9 Single phase sag magnitude Minimun stage duration Single phase sag duration System under fault Recovery Fall Time

8. SIGNIFICANT INFORMATION OF VOLTAGE SAGS (IV) k=0 k=2 k=4 k=3 k=5 k=1 Characterisation of faults based on symmetrical components [Bollen & Zhang 98] Type A: equal voltage drop in three phases Type Ca: voltage drop between phases b and c Type Da: voltage drop in phase a The voltage sag type indicates which phases are involved in the event.

9. CLASSIFICATION METHOD (I) x1: Sag duration x2: Sag magnitude Stored sag data New sag x1: Sag duration x2: Sag magnitude xn: Recovery slope Recognition xn: Recovery slope Unsupervised Learning Classes and learning parameters Classes and learning parameters Relationship between Classes and Location of sags Classes and learning parameters General Functionality Training Classification

10. Class 1 Class 2 Class 3 Class 4 CLASSIFICATION METHOD (II) Unsupervised Learning Classificationspace

11. x1: Sag duration descriptor x1 ofCj x2 : Sag magnitude L descriptor x2 of Cj x mCj ( x ) Voltage Sag Global Adequacy Degree(GAD) xn : Recovery slope descriptor xn of Cj Marginal Adequacy Degree(MAD) CLASSIFICATION METHOD (V) Recognition Process

12. CLASSIFICATION METHOD (III) Vrms [p.u.] 1.0 0.9 Fall System under fault Recovery Time Classification Classification Classification Individual classification 1 - 5 1 - 6 1 - 4 Transversal classification 111 - 564 Classification steps

13. 1 1 3 Transversal analysis CLASSIFICATION RESULTS AND FAULT DIAGNOSIS APPROACH (I) Individual analysis for voltage sags

14. Meaningful information CLASSIFICATION RESULTS AND FAULT DIAGNOSIS APPROACH (II) Transversal analysis for voltage sags

15. Transmission Transmission Distribution ?? CLASSIFICATION RESULTS AND FAULT DIAGNOSIS APPROACH (III) Occurrence class for voltage sag classification

16. CLASSIFICATION RESULTS AND FAULT DIAGNOSIS APPROACH (IV) Class composition according to type of transmission voltage sags

17. CLASSIFICATION RESULTS AND FAULT DIAGNOSIS APPROACH (V) Class composition according to type of distribution voltage sags

18. CONCLUSIONS (I) A classification tool has been used to relate voltage sags to their possible location (transmission or distribution).

19. CONCLUSIONS (II) The proposed approach helps to determine classes that are strongly related to the fault location.

20. Voltage sag data recording Future Work (I) To increase the number of registered sags in order to improve the classification.

21. Future Work (II) To develop a stand-alone application to be used in the substation to assist in fault location.

22. CLASSIFICATION OF SHORT DURATION FAULTS (VOLTAGE SAGS) IN TRANSMISSION AND DISTRIBUTION POWER SYSTEMS David Llanos Joaquim Meléndez Joan Colomer dllanosr@eia.udg.es quimmel@eia.udg.es colomer@eia.udg.es Juan Mora Magda Ruiz jjmora@eia.udg.es mlruizo@eia.udg.es Javier Corbella Jorge Sánchez fjCorbella@enher.es jslosada@fecsa.es http://eia.udg.es/~secse http://eia.udg.es/exit Departament d’Electrònica, Informàtica i Automàtica (EIA)

25. CASE BASED REASONING (CBR) • Based on the 4R Cycle (Retrieve, Reuse, Revise and Retain). [Aamodt & Plaza 94] • A case contains information of the Problem and Solution Spaces

26. k=0: type Ca k=1: type Dc k=2: type Cb k=3: type Da k=4: type Cc k=5: type Db SIGNIFICANT INFORMATION OF VOLTAGE SAGS (IV) Characterisation of faults based on symmetrical components [Bollen & Zhang 98] The voltage sag type indicates which phases are involved in the event.

27. FUZZY CLASSIFICATION METHOD (III) Vrms [p.u.] 1.0 0.9 Fall System under fault Recovery Time Descriptors • Fall slope • Sag magnitude • ... Descriptors • Sag duration • Sag magnitude • ... Descriptors • Sag magnitude • Recovery slope • ... Unsupervised learning Classification Classification Classification Individual classification 1 - 5 1 - 6 1 - 5 Transversal classification 111 - 565 Classification steps