# Research on Key Technology of Wind Turbine Drive Train Fault Diagnosis System Based on Digital Twin
## 4 Fault Diagnosis Method Based on Digital Twin  
### Implementation Method of Fault Diagnosis System Based on Digital Twin  
The benefits of digital twin technology in troubleshooting lie in its ability to enable real-time monitoring, simulation, and emulation of natural systems, reduction in maintenance costs, optimization of repair solutions, and knowledge management and iterative optimization. Through real-time monitoring, digital twin technology can capture changes in the operational status of the actual system and compare it with the virtual model to detect potential signs of failure. In terms of simulation and emulation, digital twin technology can simulate the operation of the actual system in a virtual environment to quickly test different failure assumptions and repair options, reducing the cost and time of trial and error. Reducing maintenance costs is another significant advantage of digital twin technology. By analyzing equipment operation data, predictive maintenance can be achieved to identify and solve potential failures in a timely manner, avoiding production stoppages and increased maintenance costs brought about by sudden failures. Additionally, digital twin technology can achieve the accumulation and management of knowledge through the continuous analysis of maintenance records and operation data, providing data support for the continuous optimization of the system, which improves production efficiency and equipment reliability. In summary, digital twin technology has multiple advantages in fault diagnosis, which can help enterprises reduce maintenance costs, improve productivity, and enhance equipment reliability. This chapter proposes a wind turbine condition monitoring and fault diagnosis system based on digital twin technology. The system utilizes a variety of sensors and data acquisition devices to collect data related to the operating state of the wind turbine. Subsequently, the actual operating state of the wind turbine drive train is mapped onto the digital twin model through digital twin technology, which enables us to monitor the operating state of the wind turbine in real-time and detect potential faults in time. The framework of the intelligent monitoring and fault diagnosis system for wind turbine drive trains based on digital twins is shown in Figure 7.  
The SCADA system was connected with the digital twin platform for data connection; when the system was running, real-time operation data of wind turbines in the SCADA  
Figure 7: Framework of intelligent monitoring and fault diagnosis system for wind turbines based on digital twins. system was obtained through TCP/IP connection protocols and displayed in Unity3D. Meanwhile, vibration data collected by each sensor was input into the fault diagnosis model. According to the diagnosis results, the virtual model is driven to simulate the behavior of the real physical wind turbine in the whole scene and realize the virtual and natural interaction. Specific steps are as follows:  
**Step 1**: The digital twin fault diagnosis system of the wind power transmission system collects the vibration signal of the wind turbine. **Step 2**: The data acquisition card is used to convert the analog signal collected by the acceleration sensor into a digital signal and transfer it to the PC. **Step 3**: The collected data are saved as a.CSV or.txt file by data acquisition software and exported to Unity3D. **Step 4**: The IVMD-PSO-LSSVM is packaged as a DLL file and integrated into the digital twin file. **Step 5**: The digital twin periodically or manually invokes vibration signals for fault diagnosis. **Step 6**: The digital twin model updates its running status according to the diagnosis results and is displayed in Unity3D. In order to ensure the real-time nature of the data, a transmission method and communication protocol with fast transmission speed and high accuracy should be used, and the wind turbine operation status data can be displayed in real-time first and then stored in the database or both can be processed in parallel.