Design Of Experiment Platform For Fault Diagnosis And Fault-tolerant Control Of Variable Frequency Speed Regulation

The AC motor variable frequency speed control system has a wide range of applications in modern industry,and its stability and reliability play a vital role in the entire production environment.Among all kinds of faults that may occur during the operation of the variable frequency speed regulation system,the power device of the power converter is one of the components with the highest failure rate,and its open circuit fault diagnosis method is one of the research hotspots in related fields.In the current research and experimental work,there are problems such as low experimental efficiency,inconvenient system monitoring,and insufficient computing power,which has brought great obstacles to the verification and research of fault diagnosis algorithms and fault-tolerant control strategies.Therefore,this thesis designs and implements an easy to expand,easy to observe,multi-degree-of-freedom fault diagnosis and fault-tolerant control experiment platform.The thesis takes the power converter of AC motor variable frequency speed regulation system as an object,designs and develops an experimental platform with system status monitoring,fault simulation,fault diagnosis algorithm and fault-tolerant control algorithm implementation and test functions.The experimental platform implements the Ethernet communication technology based on the C/S architecture,which is divided into the lower computer system(client)and the upper computer monitoring software(server).The design of the lower computer system accomplishes the signal acquisition,AC motor frequency conversion speed control,power tube open circuit fault simulation,TCP communication client,online fault diagnosis algorithm and fault tolerance control algorithm experimental test function that based on TMS320F28335.The power converter with dynamic reconstruction capability of fault-tolerant topology is archieved to meet the hardware requirements of different faulttolerant control algorithms.The upper computer monitoring software is a real-time monitor of the lower computer system,which is responsible for real-time monitoring of the hardware system status of the AC motor variable frequency speed control system,issuing speed regulation and load change and fault simulation instructions.In the thesis,the modular design method based on Qt framework is adopted,and the host computer monitoring software is divided into communication module,database module,analog oscilloscope and fault diagnosis algorithm expansion interface,which are designed and developed separately.Among them,the extended interface of the fault diagnosis algorithm achieves good external script adaptability,which is convenient for researchers to carry out more complicated fault diagnosis algorithm experiments and research based on the host computer.The thesis selects a fault diagnosis algorithm and fault-tolerant control algorithm from the published literature,implements it based on the experimental platform and tests the function of the experimental platform.The test results show that the experimental platform can realize the variable frequency speed control of the AC motor,simulate open circuit faults of multiple power tubes,verify fault diagnosis and fault-tolerant control algorithms and monitor the running state of the variable frequency speed control system in real time.