G&W has been supplying solutions for power automation and voltage loss reconfiguration requirements for many years. Whether the need is a standalone automatic transfer switch or an advanced multiple source system reconfiguration package with high speed transfers and synchronized returns for smart grid applications, G&W’s experience in Preferred/Alternate, Main/Tie/Main, and Multisource Load shedding applications allows us to provide a customized solution that will meet or exceed your specific requirements.
Our Lazer Automation system is designed to help decrease outage time and cost while improving reliability. Each G&W Lazer Voltage Loss package includes options for switchgear, communication equipment and programming. You may choose from:
Please contact your local G&W representative to receive a complete review of your current project requirements and recommended G&W solution. Please click on one of the tabs below to review some of our customer installations.
Five Source High Speed Automatic Reconfiguration A Big10 university wanted to improve reliability on their 15kV underground system which fed the campus. They envisioned an automated system that would sense outages and use a combination of automatic transfer control and automatic fault isolation to minimize circuit outages. G&W’s long history with the university and design flexibility worked together to supply five SF6 insulated switches. Each switch included stored energy two-position mechanisms (capable of operating in 10 cycles) and manual three position grounding mechanisms. In addition, G&W supplied a stand alone control panel that could operate all 5 pieces of switchgear (9 automated mechanisms) from the main vault with 2 of the switches residing in different vaults.
Automatic Transfer with Load Shedding
An airport expansion project required a two source automatic transfer scheme that would monitor the sources, transfer only the acceptable amount of load to the new source, and return normal power in a predetermined order of prioritization.
G&W utilized our system integration and pre-shipment system testing expertise to provide LPFI SF6 insulated switchgear , SEL relays and an industrial computer all communicating via fiber optic cables. The system, designed to disconnect lower priority loads when the preferred source is lost, was fully tested prior to shipment. Once the switches were set on the pads on-site, commissioning of the automation system took about 2 hours.
For more information: Link to Application Guide
A critical customer required not only source side automatic transfer but also load side overcurrent protection in an overhead application.
By pairing G&W’s Viper-S reclosers which include built-in three phase voltage and current sensing, with SEL351R recloser controls this utility was able to mount the reclosers at the best location for the utility, not just the closest junction point. Since this application used fiber optic cable for communication the total restoration time was tested at as few as 8 cycles. In addition, should a load side overcurrent condition occur, the controls were set to override the automatic transfer logic and utilize its trip and reclose feature.
For more information: Application Guide
In the process of upgrading a substation, a local power agency supplied a concept sketch and specification that detailed their need for a four source reconfiguration solution. In addition to very specific needs in regards to equipment and operation, the solution needed to work at both 12.47kV and 12kV.
G&W was able to provide two pieces of SF6 insulated switchgear with both loadbreak and fault interrupting mechanisms, internal voltage sensing bushings, and external metering CTs along with a standalone outdoor control cabinet.
A Canadian utility was interested in improving reliability on one of their overhead circuits that was fed by two separate sources and provided both commercial and residential loads via several kilometers of overhead cables. The goal was to minimize the power interruption to the customers during the loss of one of the sources.
G&W, along with Canada Power Products, worked with the customer to design a distributed main-tie-main (Bus Tie) automatic transfer solution to minimize the outage time. The system consisted of three Viper-ST reclosers with intelligent relays communicating with each other. Two of the reclosers were installed on the incoming sources with the third recloser in between them as a normally open point. MDS TransNet radios with Yagi directional antennas were used to communicate between the reclosers. Each control included the ability for the customer to select between pure manual operation, an automatic transfer with an open initial transition and closed return transition or an automatic transfer with an open initial transition and manual return transfer. Both automated schemes would block the transfer function if an overcurrent fault was detected. In addition, DNP maps were defined for future SCADA connections.
The scheme was fully tested and its operation witnessed by the customer in Canada Power Products’ Mississauga, Ontario facility. The scheme has operated several times since installation and customers maintained power that would not have without the distribution automation system in place.