Enhancing remote monitoring and control on wind farms
Large wind turbines provide a very good source of renewable energy, but are usually situated remotely - especially when offshore - and may be smart grid connected, so having efficient systems networking, monitoring and controlling of the turbines and related farm equipment is crucial. EtherWAN’s wind generation networking systems are already at work in the North West of China, as the following case study shows.
WIND ENERGY IS probably the least problematic way to generate power, despite the wind not always blowing when wanted. Developing offshore wind power projects to meet China’s ambitious energy targets is a top priority. At present, a mere 1% of the county’s power is generated by wind. With the second longest coastline in Asia, the Chinese government is fast developing wind power concession in 11 coastal provinces and is also constructing a number of large offshore wind farm projects. A wind turbine is more complex than might initially be thought, typically comprising blades, nacelle and tower, gearboxes and bearings, anemometer, generator, medium voltage transformer, power converter, pitch/tilt control panels, power distribution transformer panel, plus the control panel itself. In order to interconnect wind turbines and uplink to a wind tower control box, wind power systems require networking devices with long-hour transmission capability.
A group of wind turbines generates electricity for the utility grid and sends the electricity (and data) through transmission and distribution lines to a distribution centre and control room that may be hundreds of miles away. A drawback is that the wind does not blow continuously, so it can be difficult for utilities to maintain a reliable source of energy throughout the year. This is why the ‘smart grid’, which allows for more efficient use of wind power, is so essential for success.Communication between wind turbines and the control centre is a major concern because of the large scale of wind farms – particularly those off-shore. It is essential that wind farms use hardened and ruggedised networking devices for long distance transmission. The challenge is to provide a reliable industrial Ethernet network to allow remote monitoring, diagnostics and control to individual wind turbines and to the wind farm as a whole.
EtherWAN was contracted to supply the network components (Fig. 1). The company's EX42000 series unmanaged industrial Ethernet switches have been installed in each wind turbine tower’s control box. Each control box contains a PLC, serial device server and a switch, which convert the data over copper Ethernet to fibreoptic transmissions. The base of each tower uses the company's EX71000 managed hardened Ethernet switches that provide network redundancy (with EtherWAN's α-Ring, which provides reliableb data transmission). Theαa-Ring protocol was designed to overcome traditional STP and RSTP's inability to provide fast network recovery in minimising packet loss caused by link failure. The switch enables long distance fibre transmission for wind farm networks that extend to the control room hundreds of miles away. Copper Ethernet media connects to PCs or RJ45-equipped PLCs, while fibre Ethernet connects to one of the fibre ring switches, and sometimes directly to the wind farm utility company’s central office.The control centre needs the data to obtain crucial electrical power measurements and toproperly maintain the wind power facility, bearing in mind that the loss of a single day through downtime for a single 1.5MW wind turbine working at full load is estimated to cost around euro 60,600 ($80,000)  .
The hardened grade equipment installed supports fibreoptic andαa-Ring technologies with advanced network management features for building cost-effective, reliable wind farms.
The result is a successful deployment of modern wind generation systems in North West China.
 Source: NREL - www.nrel.gov
Case study supplied by EtherWAN.
EtherWAN Systems, founded in 1996 in Irvine CA, has become a leader in Ethernet connectivity for applications in various markets including IP Surveillance, Intelligent Transportation Systems (ITS), Renewable Energy, Smart Grid, Utility, Oil & Mining, Factory Automation, etc. EtherWAN specializes in designing and manufacturing fiber optic Ethernet products and Ethernet equipment for harsh environments. The available products are hardened Ethernet over VDSL equipments, hardened media converters from serial/Ethernet to fiber or wireless, PoE switches, IEC61850 based hardened Ethernet equipments for power distribution and substation applications, EN50121-4 & EN50155 based products for railway and train networking applications, and those for UL1604 based hazardous locations. EtherWAN's US headquarters are located in California USA with Pacific Rim headquarters and manufacturing facility in Taipei, Taiwan. With engineering expertise at both sides of the Pacific Ocean and its own production lines in Taiwan, EtherWAN continues to serve the markets with most advanced Ethernet gears at very affordable prices.