Within a single turbine the various controllers communicate with each other via wired technology. When communicating at high data rates or over the relatively long distances within a turbine, differential data transmission offers superior performance to single-ended transmission. Popular protocols for this communication task are RS-485 and CAN. Analog Devices offers a wide range of iCoupler®-based isolated RS-485/RS-422 transceivers to suit this application with the ADM248xE and ADM258xE families which include integrated isolated dc/dc converters. More recently, Analog Devices’ has released the first of a family of isolated CAN transceivers, the ADM3052/3053, with and without an integrated isolated dc/dc converter. For proprietary protocols there are also numerous standard iCouplers available such as the ADuM140x family, which are quad channel isolators.
Measurement / Sensing
For current sensing, galvanic isolation is mandatory and current transformers (CTs) have been widely used to date for this purpose while Hall effect and shunt resistors have been less popular here due to the high currents involved. Each sensor type has its own advantages and disadvantages but all require precision, low noise, low power op amps like ADI’s OPX177 family to complete the signal conditioning demanded by the signals of different current sensors.
For position sensing of the gearbox output shaft high resolution resolvers are employed due to their mechanical integrity and ability to work in harsh environments. Suitable RDCs for this application are ADI's AD2S1205 and AD2S1210 components.
Vibration analysis is an important tool in early identification of developing problems in rotating machines. Bad bearings, worn gears, loose fittings, and misaligned equipment, especially in the larger 1MW + wind turbines, can have a profound impact on the operational lifetime and maintenance costs of grid-connected wind turbines. For vibration analysis and predictive maintenance purposes the new iSensor® product, the ADIS16227, is uniquely capable of delivering an embedded vibration monitoring system. Built around ADI’s own tri-axial MEMS technology, this module offers a sophisticated suite of FFT analysis algorithms, programmable spectral alarm bands and user-configurable multimode operation to monitor, detect, analyze and capture, in a single module, all pertinent vibration data.