Xianjiang Shi

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Research the effect of stator current of asynchronous motor on shafting torsional vibration under variable-frequency power sources, a simulation model of shafting torsional vibration detection based on MATLAB/SIMULINK is aiming at revealing response and law of stator current on shafting torsional vibration in the event of inverter power supplying, which(More)
According to wavelet de-noising and the Hilbert transform theory, a boxed-milk metamorphism rapid detection device and identification method are proposed. Wavelet de-noising method is used to eliminate signal noise, then the use of Hilbert transform for envelope Ways to achieve signal envelope curve, and then for the system damping ratio. Under the case(More)
The conventional PID control of most processes has good control effect and robustness. Without adaptive capacity and prone to elicit inertia delay, this method can only be applied in a special working condition. This paper puts forward a composite fuzzy PID control method based on the establishment of fuzzy rules and the compound of PID controller, as well(More)
The problem that the mechanical fault information of wind turbine generator is weak in the voltage and current signals need to be solved, information is not conducive to the identification and extraction. According to the common algorithm, the instantaneous power and other parameters are combined well, and we exploit the characteristic of mechanical fault(More)
In order to realize on-line monitor and diagnosis of the fault of the gearbox of a wind driven generator a method of automatic selection frequency-band based on wavelet analysis and kurtosis rule has been put forward. Firstly, a vibration signal is multiple discomposed by using wavelet transformation, and then the kurtosis for wavelet coefficients of(More)
In order to improve the detecting accuracy of the fast-detection device of the UHT(Ultra Heat Treated) box milk quality, the method of wavelet de-noising is applied to the free damped torsional vibration signals produced by the liquid milk box. And by getting the envelope demodulation using the Hilbert transform, the damping ratio of the system is finally(More)
In order to solve the problem of accurate simulation modeling and equation solving difficulties of asynchronous motor broken bar fault. By using the simulation module of the winding asynchronous motor, establish the simulation model of the simple broken bar fault in the SIMULINK environment. We discuss the motor current fault diagnosis method of broken bars(More)
In order to solve the less fault frequencies and unsymmetrical sideband problem in the usual modulation signal of zoom spectrum, according to the principle of modulation frequency shift keying, advance real modulation frequency shift keying algorithm which can realize frequency range and frequency spectrum symmetry. After filtering and re-sampling the real(More)
Reliability and maintainability of mechanical equipment are researched through quantitative and qualitative analysis, and statistical analysis is calculated with the example of 1K36-type turret lathe, and reliability and maintainability parameters of 1K36-type turret lathe and its subsystems are gained. The results show that reliability function shows(More)