Lecciones del terremoto de Chile 2010 y su impacto en el suministro eléctrico

Hugh Rudnick

Preocupación en la sociedad moderna

Suministro seguro de servicios básicos

Alta dependencia de suministro eléctrico

Impactos diversos en suministro eléctrico por

Problemas de abastecimiento de combustibles

Guerras, conflictos políticos, terrorismo

Desastres naturales (huracanes, terremotos, maremotos, erupciones volcánicas, etc.)

Necesidad estar preparados para enfrentarlos

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Seguridad de abastecimiento eléctrico

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Araneda, Juan Carlos (Transelec), Rudnick, Hugh (PUC), Mocarquer, Sebastian (Systep), Miquel, Pedro (Systep), "Lessons from the 2010 Chilean earthquake and its impact on electricity supply", 2010 International Conference on Power System Technology (Powercon 2010), Hangzhou, China, October 24-28, 2010

1575 Valdivia 8.5 1730 Valparaiso 8.7 1751 Concepción 8.5 1835 Concepción 8.5 1868 Arica 9.0 1906 Valparaíso 8.2 1922 Vallenar 8.5 1943 Coquimbo 8.2 1960 Valdivia 9.5 1985 Santiago 8.0 1995 Antofagasta 8.0

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Large earthquakes in Chile

• 03:34 hrs. February 27 2010

• 8.8 Richter shakes 6 regions of Chile

along 500 km (80 % of population)

• Tsunami hits the cost minutes after

• Death toll: 521; Missing: 56

• Injured: 12,000; Displaced: 800,000

• Infrastructure affected:

• 370,000 houses

• 4,013 schools

• 79 hospitals

• 4,200 boats damaged

• Economic loss: 30 billion US dollars

• Acceleration of 0.65 g in Concepcion

• 10 meter average plaques displacement

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The 2010 earthquake

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Large acceleration for long time

Peak acceleration of 0.65 g for one of the horizontal records. Duration of strong shaking for 70 seconds

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Its effects– structural collapses

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Its effects– building collapses

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Effects of the tsunami

High standard of seismic requirements for its civil works. Building codes in Chile are substantially the same as US codes (ACI 318, a leading concrete design reference for building codes worldwide issued by the American Concrete Institute).

High voltage electrical facilities, the national technical standard establishes that facilities must obligatorily fulfill the ETG 1.015 Chilean standard or the IEEE 693 standard in the condition of High Performance Level. It specifies a maximum 0.50 g acceleration and a maximum horizontal displacement of 25 cm. to be considered in the design as the seismic intensity at the facility location.

Specific electrical requirements for installation construction and maintenance through Technical Norm of Security and Quality of Service, which defines technical and economic evaluations to determine the reliability level on the planning and operation of the power system.

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Norms and standards in Chile

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SIC

Immediate blackout for 4,522 load (peak demand of 6,145 MW and installed capacity of 11,023 MW)

Longitudinal transmission system over 2,200 km long

Grid lines mainly at 220 kV and 500 kV

Five, then two, island scheme for grid supply recovery

Distribution networks severely damaged

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Evolution of electricity supply

Black out with loss of 3,000 MW

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Evolution of electricity demand

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Impact on operation

Severe impacts on country communication systems. Basic systems (mobile networks, emergency alert schemes, public order control), electricity dependant, did not operate as desired and caused additional harm.

Difficulties also arose in the communications and telecontrol schemes of most electricity installations, transmission substations and generating plants, complicating plant and system recovery and operation. No alternative backup radio systems.

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Impact on operation

System operator (CDEC-SIC) had additional difficulties throughout the emergency as the SCADA system in use (for over ten years), was not able to provide information required for system recovery (alarms could not be trusted as they were often incorrect).

Traditional phone calls had to be used to learn on local conditions and supervise actions for equipment and system restoration.

4,522 MW dispatched

Immediate blackout

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Dispatched generation at event

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Damage in generation plants

Bocamina plant

3,000 MW became unavailable immediately 693 MW (13 plants) went to major repairs

950 MW being built also damaged

Cooling systems,transformers, communications, lines, etc.

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But most remain available

MW (thermal plants) unavailable

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Damages in lines

Transelec has 8,239 km. of lines, 50 substations, 10,486 MW transformation capacity

Hualpen-Bocamina line (3 towers)

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Damages in substations

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Damages in substations

Capacitor bank

without damage

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But most remain available

Circuit breakers with sufficient damping

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But most remain available

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Transmission assesment

Damages concentrated in one transmission line

3 towers 154 kV line (1.6 km)

Substation damage (12 out of 46 substations, 26%). Mainly focused at:

500 kV bushings (high failure rate, particularly in transmission bushings)

500 kV pantograph disconnector switches

220 kV circuit breakers (live tank type)

154 kV circuit breakers (air compressed type)

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Transmission interconnection recovery

Recovery process of the interconnected system

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Worse extended damage in distribution

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Worse extended damage in distribution

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Worse extended damage in distribution

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But most remains standing

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Distribution damage

4.5 million people were initially affected by the extended blackout that took place because of the earthquake and it took days, and even weeks in some areas, to recover full electricity supply.

Most affected areas supplied by CGE, Emelectric and Emelat. Chilectra also affected in Santiago.

80% of clients were without supply the day after the earthquake and this reduced to 0.4% two weeks after (related mainly to Concepcion and Talcahuano, next to the earthquake epicenter).

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Distribution damage

Some distribution networks were destroyed by the effects of the earthquake, as houses fell over street lines or simply were washed away by the tsunamis (for example 40,000 houses were destroyed out of 1.5 million supplied by CGE).

Besides those distribution installations directly damaged, there was little damage elsewhere. Distribution poles in Chile are mainly compressed pre-stressed concrete poles, which are well founded, and support important mechanical stresses. Exceptions in overloaded city poles.

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Heavily loaded poles in main cities

Worse extended damage in distribution

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Small percentage damage

760,000 poles in CGE and 300,000 in Chilectra

50,000 transformers in CGE and 20,000 in Chilectra.

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Challenges in supply recovery

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Damage in distribution

Distribution aerial transformers are often placed between two poles and a steel support, thus they also withstand well an earthquake.

Main difficulties in restoring supply to houses took place at the connection point between the low voltage lines and the buildings.

Companies have equipment and human resources to repair normal failures within one or two days. But when several hundred thousand of those connections fail, as in an earthquake, the problem is quite different. Communication problems, difficult physical access to locations, no resources to manage the huge number of needed repairs. Companies involved human resources brought from other regions.

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Damage in distribution

Mobile generating sets brought to support recovery of supply, particularly in more isolated areas.

Challenges for distribution companies lasted months after the earthquake (many latent faults, caused by the quake, that could not be detected when repairs were been made days after the event, or if detected, were secondary to the objective of supplying consumers as fast as possible).

Arrival of winter, with rain and wind, started igniting these faults in a a massive way, demanding the companies to comply.

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Araneda, Juan Carlos (Transelec), Rudnick, Hugh (PUC), Mocarquer, Sebastian (Systep), Miquel, Pedro (Systep), "Lessons from the 2010 Chilean earthquake and its impact on electricity supply", 2010 International Conference on Power System Technology (Powercon 2010), Hangzhou, China, October 24-28, 2010

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Balance y conclusiones

Experiencia internacional indica mayores daños en transmisión y distribución

Altos estándares y códigos constructivos civiles y en equipos eléctricos de generación

Imposible evitar impactos de desastre natural de esa magnitud en instalaciones eléctricas

Necesidad aprovechar experiencia y producir necesarios cambios en métodos de prevención y de recuperación

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Balance y conclusiones

Balance negativo de capacidad de respuesta del país y su institucionalidad de emergencia.

Inaceptables niveles de fallas de infraestructura de comunicación

Balance positivo del nivel sísmico de la infraestructura eléctrica (particularmente en generación/transmisión)

Claras oportunidades de mejoras, particularmente a nivel de CDEC y de redes de distribución

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Balance y conclusiones

Cuidado con reacciones excesivas a evento de baja frecuencia de ocurrencia

Necesidad evaluar económicamente acciones preventivas versus correctivas.

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Agradecimientos

Transelec

CGE Distribución

CGE Transmisión

CDEC-SIC

Chilectra

American Society of Civil Engineers’ Post-Disaster Assessment Teams (Dr. Anshel Schiff, Stanford University)

Lecciones del terremoto de Chile 2010 y su impacto en el suministro eléctrico

Hugh Rudnick