Series 2000 Circuit-Switcher goes to “new heights” to provide protection for a critical load
BackgroundThe Provincial Electric Authority (PEA) in the Phimai district of Nakhon Ratchasima Province in North-eastern Thailand needed to upgrade protection for a critical load—the Pimai Salt Mine. The mine is located on a branch feeder between two separate transmis-sion substations. Downstream from the salt mine on the branch feeder, was a series of smaller less-critical residential loads. If a fault occurred at one of these residential loads, the protection scheme between the substations and the branch feeder would take the entire feeder offline, dropping the salt mine. Because the mine’s process requires pressurized steam, a significant outage could take the mine 1 to 2 days to recover from . . . losing revenue for both the mine and the utility.
How did they do it?The utility looked for a solution that didn’t rely on the upstream substation circuit breakers for load-break capability. Initially PEA planned to use a mobile substation between the mine and the residential load to isolate the salt mine from downstream outages. But due to zoning and local land management policies, purchasing land to install a permanent switching station would have been difficult and costly . . . as would be negotiating a new right-of-way to reconfigure the way the residential load is supplied. They considered circuit breakers, but the size of a circuit breaker, plus the structure for a separate isolating disconnect would also require a permanent land-based switching station.
ResultsThe solution was a Series 2000 Circuit-Switcher, Model 2010. Using the existing right-of-way and transmission structure, a 115-kV Series 2000 Circuit-Switcher was modified by S&C Switch Products Division’s Technical Services department for installation six meters off the ground on a custom built “floating” switching platform. The Circuit-Switcher was installed with a coordinating set of voltage and current sensors and a relay cabinet with distance relays for fault monitoring along the branch feeder. See Figures 1 and 2. The Series 2000 Circuit-Switcher with integral disconnect has the full load-break rating the utility required, and is lightweight and compact enough to mount on the transmission structure. And the Series 2000 is a significant cost-savings over both the real estate requirements for a land-based substation and equipment costs of a circuit breaker.
The utility is considering revising their specifications to use the Series 2000 Circuit-Switcher and associated sensing and relaying as one of their standard design “modules” when a transmission sectionalizing station is needed, and is also considering specifying Series 2000 Circuit-Switchers in their “mini-substation (50 MVA or lower) module” to help improve the reliability of their system.
Figure 2. Switching station using Series 2000 Circuit-Switcher.
Figure 1. Series 2000 with voltage and current sensors.
Series 2000 Circuit-Switcher goes to “new heights” to provide protection for a critical load
BackgroundThe Provincial Electric Authority (PEA) in the Phimai district of Nakhon Ratchasima Province in North-eastern Thailand needed to upgrade protection for a critical load—the Pimai Salt Mine. The mine is located on a branch feeder between two separate transmis-sion substations. Downstream from the salt mine on the branch feeder, was a series of smaller less-critical residential loads. If a fault occurred at one of these residential loads, the protection scheme between the substations and the branch feeder would take the entire feeder offline, dropping the salt mine. Because the mine’s process requires pressurized steam, a significant outage could take the mine 1 to 2 days to recover from . . . losing revenue for both the mine and the utility.
How did they do it?The utility looked for a solution that didn’t rely on the upstream substation circuit breakers for load-break capability. Initially PEA planned to use a mobile substation between the mine and the residential load to isolate the salt mine from downstream outages. But due to zoning and local land management policies, purchasing land to install a permanent switching station would have been difficult and costly . . . as would be negotiating a new right-of-way to reconfigure the way the residential load is supplied. They considered circuit breakers, but the size of a circuit breaker, plus the structure for a separate isolating disconnect would also require a permanent land-based switching station.
ResultsThe solution was a Series 2000 Circuit-Switcher, Model 2010. Using the existing right-of-way and transmission structure, a 115-kV Series 2000 Circuit-Switcher was modified by S&C Switch Products Division’s Technical Services department for installation six meters off the ground on a custom built “floating” switching platform. The Circuit-Switcher was installed with a coordinating set of voltage and current sensors and a relay cabinet with distance relays for fault monitoring along the branch feeder. See Figures 1 and 2. The Series 2000 Circuit-Switcher with integral disconnect has the full load-break rating the utility required, and is lightweight and compact enough to mount on the transmission structure. And the Series 2000 is a significant cost-savings over both the real estate requirements for a land-based substation and equipment costs of a circuit breaker.
The utility is considering revising their specifications to use the Series 2000 Circuit-Switcher and associated sensing and relaying as one of their standard design “modules” when a transmission sectionalizing station is needed, and is also considering specifying Series 2000 Circuit-Switchers in their “mini-substation (50 MVA or lower) module” to help improve the reliability of their system.
Figure 2. Switching station using Series 2000 Circuit-Switcher.
Figure 1. Series 2000 with voltage and current sensors.
Series 2000 Circuit-Switcher goes to “new heights” to provide protection for a critical load
BackgroundThe Provincial Electric Authority (PEA) in the Phimai district of Nakhon Ratchasima Province in North-eastern Thailand needed to upgrade protection for a critical load—the Pimai Salt Mine. The mine is located on a branch feeder between two separate transmis-sion substations. Downstream from the salt mine on the branch feeder, was a series of smaller less-critical residential loads. If a fault occurred at one of these residential loads, the protection scheme between the substations and the branch feeder would take the entire feeder offline, dropping the salt mine. Because the mine’s process requires pressurized steam, a significant outage could take the mine 1 to 2 days to recover from . . . losing revenue for both the mine and the utility.
How did they do it?The utility looked for a solution that didn’t rely on the upstream substation circuit breakers for load-break capability. Initially PEA planned to use a mobile substation between the mine and the residential load to isolate the salt mine from downstream outages. But due to zoning and local land management policies, purchasing land to install a permanent switching station would have been difficult and costly . . . as would be negotiating a new right-of-way to reconfigure the way the residential load is supplied. They considered circuit breakers, but the size of a circuit breaker, plus the structure for a separate isolating disconnect would also require a permanent land-based switching station.
ResultsThe solution was a Series 2000 Circuit-Switcher, Model 2010. Using the existing right-of-way and transmission structure, a 115-kV Series 2000 Circuit-Switcher was modified by S&C Switch Products Division’s Technical Services department for installation six meters off the ground on a custom built “floating” switching platform. The Circuit-Switcher was installed with a coordinating set of voltage and current sensors and a relay cabinet with distance relays for fault monitoring along the branch feeder. See Figures 1 and 2. The Series 2000 Circuit-Switcher with integral disconnect has the full load-break rating the utility required, and is lightweight and compact enough to mount on the transmission structure. And the Series 2000 is a significant cost-savings over both the real estate requirements for a land-based substation and equipment costs of a circuit breaker.
The utility is considering revising their specifications to use the Series 2000 Circuit-Switcher and associated sensing and relaying as one of their standard design “modules” when a transmission sectionalizing station is needed, and is also considering specifying Series 2000 Circuit-Switchers in their “mini-substation (50 MVA or lower) module” to help improve the reliability of their system.
Figure 2. Switching station using Series 2000 Circuit-Switcher.
Figure 1. Series 2000 with voltage and current sensors.
El Circuit-Switcher Serie 2000 llega a “nuevas alturas” para brindar protección a una carga críticaAntecedentesLa compañía Provincial Electric Utilities (PEA) en el distri-to Phimai de la provincia Nakhon Ratchasima al noreste de Tailandia necesitaba actualizar la protección de una carga crítica—la mina de sal Pimai. La mina está ubicada en un alimentador ramal entre dos subestaciones de transmisión separadas. Aguas abajo de la mina de sal en el alimenta-dor ramal había una serie de cargas domiciliares de índole menos crítica. Si ocurría una falla en una de dichas cargas domiciliares, el esquema de protección entre las subesta-ciones y el alimentador ramal apagaba el alimentador com-pleto, dejando sin electricidad a la mina de sal. Debido a que el proceso de la mina requiere de vapor presurizado, un corte de energía de magnitud considerable provocaba que la mina se tardara de 1 a 2 días en recuperarse…lo cual implicaba pérdidas tanto para la mina como para la compa-ñía eléctrica.
¿Qué fue lo que hicieron?La compañía eléctrica buscó una solución que no requería de interruptores de circuito aguas arriba de la subestación para contar con capacidad de rompecarga. En un principio PEA planeaba utilizar una subestación móvil entre la mina y la carga domiciliar para que la mina quedara aislada de los cortes de energía de aguas abajo. Sin embargo, debido a la zonificación y a las políticas locales de gestión de tierras, adquirir un terreno para instalar una estación permanente de seccionamiento hubiese sido una tarea difícil y costo-sa…y de igual manera lo hubiese sido negociar un nuevo derecho de paso para reconfigurar la vía mediante la cual se suministra la carga domiciliar. Tomaron en cuenta los interruptores de circuito, pero el tamaño de estos, aunado a la estructura necesaria para instalar un seccionador aislador separado también requeriría de una estación permanente de seccionamiento instalada en tierra.
ResultadosLa solución fue un Circuit-Switcher Serie 2000, Modelo 2010. Al utilizar el derecho de paso y la estructura de trans-misión existente, un Circuit-Switcher Serie 2000 de 115-kV fue modificado por el Departamento de Servicios Técnicos de la División de Productos de Seccionamiento de S&C para poder instalarlo seis metros por encima de la tierra sobre una plataforma de seccionamiento “flotante” hecha según las necesidades del cliente. El Circuit-Switcher fue instalado con un juego coordinante de sensores de tensión y corrien-te y un gabinete con relevadores de distancia para monito-rear las fallas en todo lo largo del alimentador ramal. Ver Figuras 1 y 2. El Circuit-Switcher Serie 2000 con cuchilla in-tegral cuenta con la capacidad plena de rompecarga que la compañía eléctrica requiere, y es lo suficientemente liviano y compacto para poder quedar montado sobre la estructu-ra de transmisión. Además, el Circuit-Switcher Serie 2000 supone grandes ahorros tanto en términos de terreno nece-sario para la subestación instalada en tierra como en cues-tiones de costos del equipo para un interruptor de circuito.
La compañía está considerando la posibilidad de revisar sus especificaciones con respecto al uso del Circuit-Switcher Se-rie 2000 y de los sensores y relevadores relacionados como uno de sus “módulos” de diseño estándar cada vez que sea necesario seccionar las zonas de transmisión de una esta-ción dada. De igual manera contempla la posibilidad de uti-lizar el Circuit-Switcher Serie 2000 en su “módulo de mini-subestación” (con capacidad igual o menor a 50 MVA)” para ayudar a mejorar el nivel de confiabilidad de su sistema.
Figura 1. Circuit-Switcher Serie 2000 con sensores de tensión y corriente.
Figura 2. Estación de seccionamiento que utiliza el Circuit-Switcher Serie 2000.
