July 18, 2022 - GEHydro, the renewable energy division of Grenoble, France-based global energy company GE, has announced to the public that it has begun a project pilot to use RFID wireless sensors to track conditions around rotating parts inside generators for strain management and temperature data. The principle is to use the energy transfer conditions of RFID technology to attach tags to poles (also known as convex poles) that rotate around the rotator, thereby eliminating the need for wires or batteries.

The hardware portion of the system is said to use HID Global custom RFID tags with Asygn sensor chips and ImpinjRFID readers with SensThys antennas, while the software portion uses GE Hydro's own software management system. The new system captures sensor data from dozens of poles in each rotor, allowing it to detect any potential failures or maintenance needs of the power generation equipment.According to the sources, the system's customized RFID tags and paired with a complete solution allow renewable energy utilities to optimize power generation based on data related to when each rotor is working optimally or when the load may be too high.

The project was initiated in 2018 when the company sought a technology that could reduce the risk of unexpected rotor failure by providing real-time insight into the health of its rotors by providing information about the condition and data of the equipment. For example, an elevated rotor temperature could indicate a potential mechanical problem that could lead to damage to the entire system, or could require downtime for repairs.

HID built a metal RFID tag embedded with an Asygn chip, customizing the tag's antenna to operate under the unique conditions of a hydroelectric power plant. Using the chip, data generated from power transmissions received from RFID readers can be detected and utilized, while also synchronizing most standard EPC UHF RFID readers on the market. GE Hydro is expected to be able to expand the solution in real time this year.

Environmental factors present unique challenges to the use of RFID technology. First, tags are exposed to temperatures in excess of 100 degrees Celsius (212 degrees Fahrenheit). As a result, HID's engineers built tags that not only needed to withstand the heat, but also needed to transmit at the same read distance (approximately 1.5 meters (4.9 feet)) regardless of exposure to high temperatures.

Another challenge was to attach a chip to each tag to measure the temperature and changes on the rod, rather than the other materials surrounding it. The tag uses a design that mounts directly to the metal, while the chip sits on the surface of the metal being tracked.

The biggest challenge, however, was the rotation of the rotor. The system spins at 800 revolutions per minute, providing the reader with approximately 10 milliseconds to transmit power to power the chip and then receive the chip's sensor readings. The tag antenna is optimized for high speed transmission in this environment. When the reader identifies the label, the label chip must receive the energy, complete the sensor measurement and return transmission, so this series of actions need to be completed in 10 milliseconds of time.

GE Hydro wanted to capture more data about potential problems or equipment failures by adding strain sensors to an existing solution. For example, the expansion of a metal plate at high temperatures creates the potential for fracture. With this technology, GE Hydro wanted to detect temperature changes along with how these fluctuations affect the integrity of metal parts. The Impinj Speedway R420 reader with SensThys SensRF-101 antenna can then capture EPC and UID numbers and other sensor data in a dedicated memory block that can be used for sensor readings.

The solution not only detects any problems with machines in real time, but also enables utilities to better manage as well as preventative maintenance. For example, by capturing data periodically and detecting progressive changes in conditions, the RFID system can analyze the conditions that cause such changes, as well as monitor the rate of part degradation to monitor when preventive maintenance needs to be scheduled.

In the long run, HID Global and Asygn plan to commercialize the wireless sensing system for use by other utility companies. They also reportedly intend to use the technology in healthcare, agriculture and other areas.