Scott Killian/Sixnet, LLC/Ballston Lake, NY/sixnet.com
A high-speed, industrial-grade network infrastructure offers wind farm operators many benefits, including improved operational management, visibility and access to key data. Networking a wind farm provides real-time data capture to monitor wind turbine uptime, performance and power output – even from remote locations. This data can be used to track efficiency and trends, plan maintenance schedules, and report the power produced and predictive information to the Independent System Operator critical to “Smart Grid” technology.
Wind farms work in a challenging environment that is not suited for traditional networking equipment. Standard “commercial grade” switches and routers were designed for use in climate-controlled data centers and wiring closets. As such, they are unable to withstand the wide temperature swings, humidity, vibration, and electromagnetic interference common to most grid connected wind farms. Since every kilowatt a wind generator produces is purchased, network interruptions and downtime leads to costly maintenance and lost revenue. Labor costs are greater in the field and even a simple 5-port switch can be expensive to replace in a remote location.
A new breed of “industrial grade” networking products is now available to seamlessly handle the extreme conditions of wind farms and address another common single point of failure – the power supply. While commercial-grade switches typically use cheap wall mounted ac-dc power supplies that plug into a standard wall receptacle, an industrial switch has two independent power supply connections hard wired to both the
dc-power bus and a backup power system.
The ideal configuration for a wind-farm network should have rugged features for extreme environments at the board level, redundant power supplies, and capabilities of “enterprise-class” software common to corporate networks. When networking a wind farm, the following six criteria should be considered for best deployment benefits:
Redundancy
Keeping the network up and running at all times is vital to wind farm efficiency and energy production. Any network downtime could lead to service interruptions and lost revenue. Not only are ruggedized networking products designed, tested, and built for the harshest environments, they have built-in redundancy to help ensure maximum uptime.
Wind farms commonly use a “ring” topology to connect turbines with fiber optic cable and then to a central location. This configuration is superior to the “star” topology common to Ethernet because the ring lets the network re-route information should a failure occur in one of its links. It is a fast, plug-and-play solution so it does not take a network specialist to deploy.
As wind farms grow in size and complexity, operators may find the need for the Rapid Spanning Tree Protocol (RSTP), a design that finds alternate and backup routes to redirect network traffic around failures in a “mesh” topology. This capability is commonly found in “managed” switches. Therefore, the ideal industrial solution is a “managed” switch that also supports a “ring” configuration so topologies can be mixed for best performance.
Additionally, the power supply is just as important as redundant topology and protocols. Ethernet switches with dual-power supplies that accept options for ac or dc voltage, or both, provide a best option for protection against a single point of failure.
Scalability
As demand for energy grows, scalability is essential to wind farm operations. “Ring” configurations, which easily support up to 50 switches, one per turbine, should be deployed because they easily interconnect for unlimited scalability. Additionally, managed switches increase flexibility in the overall network design. Used in combination or alone, managed ring switches seamlessly allow adding more turbines to a network as the wind farm grows.
Ease of use
It is important to select Ethernet switches that require little – if any – configuration work to deploy and are ready to use right out of the box. Opt for switches with plug-and-play capabilities that detect when rings are added to the network. Also, look for switches with comprehensive features, such as intuitive, easy-to-configure software and network management capabilities.
Multiple fiber support
Most industrial switches provide multi-mode fiber (MMF) and single-mode fiber (SMF). MMF provides high-bandwidth for medium distances (4km) while SMF is used for distances from 20 to 60 km.
The ideal switch supports MMF and SMF on the same unit. This flexibility allows connecting one turbine to two others at different distances without having to buy two fiber switches.
Temperature rating
Power consumption for electronic devices directly relates to temperature ratings, which in turn relates to reliability. Depending on location, temperatures near wind turbines may range from hot in the summer (75°C) to bitterly cold in the winter (-40°C). Some manufacturers design electronics to operate at particular temperatures without regard to power consumption. When asked for a higher temperature rating, they simply test boards for performance properties that will increase the life in higher-temperature environments and sell them as high-temperature-rated devices. This is why it is essential to make sure the switches purchased are designed from the outset for low power consumption and the wide range of temperatures the network will encounter.
A rugged industrial switch, including rack mounts, should be designed to withstand temperatures from -40°C to at least 75°C, and in some cases up to 85°C, without external cooling devices.
Advanced management tools
It is also important to select networking products that include enterprise-class management features in addition to its rugged design. These features should allow for easy monitoring and management of the switch’s uptime, performance, and traffic patterns to help ensure optimal network use and wind farm performance.
In addition, make sure the network is designed and installed by experienced installers trained to handle and properly terminate fiber optic cable. Improper handling, installation, or termination of fiber-cable runs can negatively affect network performance and availability, which may lead to costly repairs.
Filed Under: Projects
Good Article, but I was looking for a vibration criteria I might use to judge the degree of severity of vibration in/sec overall or peak for example. Also, the concept of low frequency tower swaying or vibration, vibration of the sails or blades, shafts, gear box and generator bearings would help. I am assuming that some components have the same criteria and horizontal or vertical machines setting directly on a pedestal on the ground, but the tower may add a different deminsion. Is that true?
Regards, Sam Duckworth, MSME Duckworth Measurement Services Austin, Texas 512 417-8616
Mr. Duckworth:
I would have to defer to the condition monitoring people to answer your questions. The flexibility of the tower certainly adds to the vibration in the nacelle but I’m not sure how much the tower is monitored. Just recently, the company RES in Colorado installed a tower at NRELs wind lab and instrumented the foundation. Results of that will not be available for about a year. I would contact the author of the article above for a more definitive answer.
Paul Dvorak