Temperature Monitoring on Wind Turbines With Wireless Data Logger MSR385WD

Wireless temperature monitoring system for wind power gearboxes based on Profinet

The wind turbine gearbox is an essential mechanical component in a wind turbine. The temperature inside the gearbox can reflect the operating condition of the gearbox. In the following case study, Hongke Technology Co., Ltd, MSR distributor in China, introduces a system that wirelessly senses the temperature inside the gearbox and integrates the MSR385WD data logger into the Profinet network to realise real-time temperature monitoring and fault warning.

Author: Amy Mai, Head of Environmental Monitoring Business Unit, Hongke Technology Co., Ltd

The Profinet network technology

Profinet is an open industrial Ethernet communication protocol proposed by the PROFIBUS & PROFINET International Association. Profinet applies TCP/IP and related information technology standards and is a real-time industrial Ethernet. Profinet is characterised by high compatibility, fast speed and high real time. Its communication rate is up to 100 Mb/s. The bus cycle time of general data transmission is hundreds of microseconds or less. Profinet plays an important role in a wide range of applications in the process industry, such as wind power generation, boiler control, oil production, fire protection and gas systems, etc. Profinet technology represents a new communication solution for the field of industrial automation, i.e. the entire plant is connected to a network.

Function of a wind turbine gearbox

The gearbox is an important mechanical component that is frequently used in wind turbines. Its main function is to transfer the energy generated by the wind turbine under the action of the wind to the generator and give it the appropriate speed. Insufficient gearbox oil injection, high oil temperature, bearing damage, friction or over-tightened seals lead to a high internal temperature of the gearbox. Detecting and monitoring the temperature inside the gearbox in real time can help identify problems and correct them in time to prevent further damage to the gearbox. Since the internal gearbox both rotates and recirculates, wireless transmission of temperature data is undoubtedly the best choice.

Ideal for remote monitoring MSR385WD measuring system with data logger and transmitter modules

The MSR385WD wireless data logger communicates with the MSR385SM wireless temperature transmitter module via 868 MHz/915 MHz band mode, taking and storing readings. The data logger can communicate with 10 transmitters simultaneously to collect and store temperature from multiple points with a memory capacity of up to 1 million readings, making it ideal for long-term temperature recording. A flash memory ensures data security in case of power failure. The data logger is powered via the USB connection; autonomous operation is possible for up to two days with the integrated Li-Po battery with 2400 mAh. The MSR385WD has an extended Modbus RTU interface that allows the data logger to be connected to the Profinet network via a gateway to enable online temperature monitoring in real time.

The MSR385SM transmitter module is equipped with a temperature sensor (-20…+125 °C), has a degree of protection of up to IP67 (one of the highest protection classes against water and dust) and has a maximum temperature resistance of 125 °C. Its robustness makes the transmitter module ideal for the complex and harsh working environment inside the wind turbine gearbox. Due to its extremely compact size (35 x 25 x 55 mm) and low weight (40 g), it can be mounted even in the hard-to-reach places of the gearbox.

Architecture of the gearbox temperature detection system

The MSR385SM transmitter module installed in the wind turbine gearbox detects the temperature change and sends the temperature signal regularly to the MSR385WD data logger. The logger connects to the gateway device via the Modbus RTU interface. The peripheral Profinet master uses the Modbus communication protocol to obtain the logger’s temperature value by cable and remotely by accessing the register address. The temperature data is displayed in the upper computer. If the temperature exceeds the set value, an alarm can be set if required.

①MSR385SM transmitter module: Installed in the gearbox. The high-precision temperature sensor records the temperature change of the most important parts in the gearbox and regularly transmits the measurement data via the 868MHz/915MHz wireless band.

②MSR385WD data logger: Installed outside the gearbox, receives the temperature data from the transmitter module, collects it, stores it and communicates with the communication module via the Modbus RTU interface.

③Profinet to RS485 gateway device: It is connected to the Modbus RTU interface of the MSR385WD data logger and uses the gateway conversion protocol to convert the Modbus data collected at the lower level into Profinet data connected to the Profinet network as a slave station.

④Profinet master station: a controller, such as PLC, acts as the master station.

⑤HMI, SCADA: Display temperature or other parameter data*.

*It can be extended with an oil pressure sensor and an ultrasonic sensor to obtain a more comprehensive system for gearbox inspection and maintenance.

Conclusion

Profinet, a new generation of industrial Ethernet technology, has strong anti-interference capability and high transmission speed, which solves the problem of real-time data transmission and stable transmission. The Profinet network-based temperature sensing system for wind turbine gearboxes integrates important temperature data within the gearbox into the higher-level computer and visualises it to enable timely understanding of the gearbox’s operating condition, issue an early warning, save labour costs and avoid greater losses due to further deterioration of the fault. Subsequent data analysis allows maintenance recommendations to be made to extend the life of the gearbox. In addition, the system offers the following advantages:

Modular design: Gear unit, temperature recording device (MSR385SM transmitter module) and recording/storage device (MSR385WD data logger), gateway device (slave station), master station as well as higher-level computer software are independent of each other and can be exchanged depending on the actual conditions.

High level of automation and low maintenance costs: The system automatically reads the temperature data, sets conditions for fault prediction and triggers alarms when needed. The wireless temperature transmitter built into the gearbox is battery powered and has a battery life of up to 10 years, reducing maintenance time, costs and downtime.

High compatibility: Integrating the gearbox’s temperature data into the Profinet network increases the system’s upward compatibility, facilitates data management and analysis, and enables accurate engineering maintenance.