Automation technology from Beckhoff has successfully proven itself in use worldwide in wind turbines up to a size of 5 MW. PC-based automation technology offers powerful controllers that unite all components of a wind turbine – such as operational management and control of pitch, generator, converter and brake, as well as Condition Monitoring and farm networking – on a single platform. Eliminating special hardware lowers the costs of the basic electrical equipment of the wind turbine and the costs of maintenance, while at the same time increasing the availability of the wind turbine.
The open, scalable automation software, TwinCAT forms the core of the Beckhoff PC-based control platform. Open interfaces permit the integration of third-party software, for SCADA, Condition Monitoring, obstruction lighting or foundation monitoring, for example. The hardware interfaces for these functions are integrated into the controller via standard EtherCAT Terminals. A large variety of interfaces enables the integration of lower-level fieldbuses such as CANopen, PROFIBUS and Ethernet TCP/IP as well as RS232/RS485. Relocating subsystems into the field considerably reduces infrastructure costs and simplifies communication.
Ultra-high-speed wind farm networking with reaction times of less than 1 ms
In comparison with conventional IP solutions, wind farm networking with EtherCAT is faster and offers considerable cost benefits. The faster the farm networking is, the more effectively the energy provider can react to voltage drops or changing requirements. With the EtherCAT Power Measurement Terminal integrated in the automation system, momentary current and voltage values can be measured at up to 10,000 samples/s at the infeed point. Early diagnosis of voltage drops is thus guaranteed. Unlike alternative solutions, it is possible to generate a reaction of an entire wind farm to an LVRT case. Thus, if a voltage drop is diagnosed at the infeed point, it can be signalled to all turbines in the entire farm within 1 ms. Via the Distributed Clocks in EtherCAT, the measured values of all wind turbines and the measurement at the infeed point of a farm can be synchronized to a timeframe smaller than 1 μs. With these data, the current, voltage and frequency can be controlled accordingly and the grid can be supported optimally. The existing fiber-optic-based Ethernet infrastructure can be used. Even the synchronization of the IGBTs of converters within a wind farm can be achieved with this technology.
Integrated Condition Monitoring solution
The importance of Condition Monitoring Systems (CMS) is continually increasing due to tightened regulations and higher demands on the availability of wind turbines. The PC- and EtherCAT-based control platform integrates the CMS function seamlessly into the existing automation system. This can be used to monitor all the turbine states, including gearbox, main bearing and generator. Apart from considerable cost benefits and flexible expandability, this solution also scores with improved diagnostics. The CMS function is integrated into the I/O terminal system via a Beckhoff EtherCAT Terminal, e.g. the EL3632. The data are acquired by the terminal and the TwinCAT automation software platform makes the raw data available within the controller. The real-time component of the CMS software is integrated into the controller via TwinCAT. The CMS analysis software, which diagnoses the acquired data and initiates a corresponding downstream service, is coupled by the user via a standard interface such as OPC. This architecture brings the user much closer to their actual goal: condition monitoring of the entire plant with time-synchronized data instead of the diagnosis of individual components.
TwinCAT 3 – universal control platform reduces engineering
TwinCAT offers the user a high degree of freedom in choosing programming languages: in addition to the object-oriented extensions of IEC 61131-3, C and C++ are now also available as programming languages for real-time applications. With the integration of Matlab®/Simulink®, TwinCAT 3 can also be used for plant simulation, for load calculation, for example.