 Controlling and Monitoring Wind Farm Installations with
Redundant Ethernet Communications
Over the past 8 years wind turbine manufacturers have embraced the use of Ethernet to monitor and control wind farms worldwide. A significant number of these installations use N-TRON switches to control, monitor and optimize the operation of the wind turbine fields from a central control room. N-TRON specializes in developing and manufacturing products for the wind energy market. N-TRON switches can be used in the harshest environments;
- Up to -40 to 85 Centigrade Operation
- 200g Shock
- 50g Vibration
- 16 KV ESD Overvoltage Protection
Many wind turbine installations are in very remote areas, and component failures will require an expensive site visit by maintenance personnel combined with the cost of equipment downtime. Designed for high reliability (2 Million Hours MTBF) N-TRON switches have become a valued part of the control schemes used by many wind turbine suppliers and integrators. Reliability of the control system will also depend on the topology used to interconnect the wind turbine towers.
Wind Turbine Topology
Figure 1 shows the topology for a single wind turbine tower. Wind turbine control schemes vary. No matter which topology is implemented, redundant Ethernet connections between each area of the wind turbine installation will increase the reliability of the system no matter how the control is distributed. In Figure 1, N-TRON’s N-Ring™ and N-Link™ protocols are used to provide a high-speed, redundant ring topology between each switch in the wind turbine network. The switches choose one path and block the other in the redundant links. If the connection being used is interrupted or fails for any reason, these switches will heal the ring by rerouting the Ethernet communications through the alternate connection within 30ms.
Using fiber cables instead of CAT5 copper cables between the control room equipment and the Nacelle will provide optical isolation between the two control areas. This will minimize the potential for damage to the network switches and connected field devices during lightning events.
Each switch in this configuration can also transmit port assigned IP addresses to the field devices connected to these ports. Any time a field device is replaced for any reason the replacement will receive the same address. This feature insures that the new device will receive the correct IP address for the SCADA control scheme. In order to take advantage of this
feature the field devices must be setup as DHCP Clients.
Wind Field Topology
Figure 2 shows an N-Ring high speed self healing ring topology. This configuration can be used
to provide redundant fiber optic rings between the control rooms of each tower in the wind
field. N-Ring will monitor and reroute Ethernet communications in the event of a break in the
fiber optic cable within 30ms. The N-Ring manager can be monitored from anywhere in the
network to determine where the break is located for quick repair (see Figure 3).
N-View™ OPC server software can be used to monitor 40 parameters on every port of each
switch using the SCADA software to control the wind field (see Figure 4) or with the standalone
N-View monitoring software provided with each switch.
A wireless access point with security (e.g. WPA2), located in each wind field provides
maintenance personnel with access to the control network without physically connecting to
the network or entering a controlled area. Area IP cameras can be used for security and IP
intercoms can provide communication throughout the wind farm.
Wind Farm Topology
Wind fields can be connected to a central wind farm control room SCADA system in order to
monitor and control all wind turbines from one location.
A gigabit Rapid Spanning Tree (RSTP) Ring is used to provide redundant communications
between all connected wind fields and the central control SCADA system (see Figure 5). The
gigabit bandwidth provided by this topology can handle data transfer to and from the wind<
fields including IP camera monitoring and Voice over IP communication.
Larger wind farms may require more IP addresses than the 254 available in one sub network.
These installations may need to segment the wind fields into separate networks using Virtual
Local Area Networks (VLANs) so that IP addresses can be reused in each field of the wind farm.
The N-TRON VLAN function will allow each port of a switch to be set to a separate VLAN ID. The
switches on the main control room ring can be setup to segment the topology of the wind farm
into separate VLANs allowing the use of duplicate IP addresses in each VLAN.
Quality of Service (QoS) is available on all switches; this allows Voice over IP and Video over IP packet prioritization. These applications require QoS to deliver voice and video without gaps in delivery due to packet buffering delays through the network.
Control schemes using EtherNet/IP™ can be used with minimal switch configuration. N-TRON switches will automatically manage the group multicast messages created by the EtherNet/IP control systems used in many wind farms.
About N-TRON
N-TRON® Corporation develops, manufactures and markets industrial network products for industrial, data acquisition, Ethernet I/O, and control applications. Globally recognized as a market leader in the Industrial Ethernet marketplace, N-TRON’s products are used throughout the world in a wide variety of applications including maritime, process control, wind farms, wastewater treatment plants, nuclear power plants, solar energy, and security and surveillance where reliability is an absolute necessity.
N-TRON is headquartered in Mobile, Alabama, with operations located throughout the United States, Canada, EMEA, India and the Pacific Rim. N-TRON products are distributed in over 75 countries worldwide.
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