Development Of Strain Test System With Wireless Transmission Function

In mainstream doubly-fed wind turbines,stress and stress concentration are the main causes of malfunction and failure of the gearbox.Stress testing and analysis of gearboxes and other components have become one of the essential links before the wind turbines are put into use.At present,strain tests on wind turbine gearboxes and other rotating components are mainly carried out in the form of wired slip rings.There are serious problems such as severe mutual interference between cables,high cost,and difficulty in long-distance testing.Based on this,this thesis introduces the main principles of strain testing and the current mainstream testing methods,and designs a wireless-based strain measurement test program for rotating components.A four-channel strain test module is designed.The module includes positive and negative power conversion circuit,variable gain amplifier circuit,DAC zero-adjustment circuit,and AD conversion circuit.The corresponding single-chip microcomputer program is programmed to realize I2C data transmission and host order acceptance.At the same time,this thesis also designed a master control module,which includes WiFi communication circuit,SD card write circuit and so on.The function is to receive the command of the upper PC through WiFi,and use the I2C bus to change the magnification of the strain test module,and then receive the test data and write it into the SD card or send it to the upper computer through WiFi.According to the system requirements,the PC host interface program was developed by LabVIEW and the upper computer controls the entire system through the WiFi module’s TCP server.In order to verify the performance of the entire system,this thesis conducted experiments on the functions of various parts of the system.The results show that the amplifier circuit and power supply circuit can meet the requirements of the strain test of the gearbox.The two-way data transmission and reception between the strain test module and the upper computer can be performed correctly,and the test data can be stored correctly.