Design And Implementation Of State Monitoring And Fault Diagnosis System Of Frequency Converter Based On LabVIEW

With the rapid development of power electronics and microelectronics technology, frequency control technique made rapid advances as the AC motor speed control mode. Frquency converter has been widely used in several areas with excellent control performance and significant energy-saving effect.Frequency converter often appears a wide variety of faults, the same as other manufacturing equipment.Systems’shutdown is not allowed owing to the continuity of production processes, otherwise it will mean huge economic losses. Therefore, fault diagnosis of frequency converter plays an important value undoubtedly.Article considers state monitoring and fault diagnosis as the backgrounds and AC-DC-AC voltage converters as the research object, through making extensive research for schematic structure and fault diagnosis method of the frquency converter, designed and implementated state monitoring and fault diagnosis system of the frquency converter based on Lab VIEW.Based on basic design principle of system, making requirements analysis for measured parameters and hardware and software, designed overall Scheme Design for hardware and software structure of the system. Using data acquisition and display capabilities of the Lab VIEW, designed data acquisition module, alarm module and the monitoring interface of the system; using Lab VIEW’s powerful signal analysis capabilities, implementated filtering, time domain analysis, wavelet denoising function; Using powerful interactive ability of Lab VIEW with the database, detailedly designed the data management of system; the use of LabVIEW and MATLAB mixed programming, detailedly designed fault diagnosis management module, implementated dynamic invocation and management of the fault diagnosis algorithm model; utilizing a strong network of communication functions in LabVIEW, DataSocket, TCP/IP and remote Panels technology is applied in the frquency converter monitoring, in order to achieve condition monitoring of the frquency converter; the system software is designed by modules, which ensures the system independent, integration and can be replant. Through the transmission of data between modules, the tasks of the whole system are completed.Secondly, this paper conducted a study on fault diagnosis of frquency converter based on wavelet neural network, using wavelet packet to extract the feature value, using the BP neural network, simulation results show that the method has less training times, fast convergence speed and less error precise, which has been able to conduct accurate fault diagnosis and verify the feasibility of BP neural network that is applied to open circuit fault diagnosis of the inverter circuit of frequency converter.Finally, it was verified that the feasibility and stability of the platform by using the actual data collected from the field and simulated data, and it was verified that the effectiveness and superiority of fault diagnosis module of this thesis by calling a different algorithm model.