Advanced Materials Research Vols. 383-390

Abstract: Based on studying Active Disturbance Rejection Control(ADRC)technology, with MATLAB / SIMULINK as simulation platform, a simple second order system as a controlled object, Specifically discussed the establishment of system module using simulink model.By the way of designing system functions for dynamic algorithms such as Tracking Differentiator and Extended State Observer, Not only can change the system parameters and simulation results can be observed after parameters changed, the simulation process becomes simple and effective. And the relationship between parameters of ADRC and the plant dynamic characteristics are analyzed when the parameters are changed, where some principles for parameters tuning of ADRC and effective applications are provided. Finally, Through simulation examples shows that the method is practical and effective.

Abstract: Active power smoothing of wind generator is very important to the utilization of wind energy. One-step ahead prediction of wind speed with the inverse-system is proposed in this paper. Wind generator is simplified as first order dynamic model. An inverse-system is designed to cascade with the model. Kalman filter and ARIMA models are used to predict the wind speed one-step ahead. The predicted wind speed is the input to the cascade system. The simulation shows that the fluctuations of the torque, the active power and the pitch angle are decreased effectively.

Abstract: Cogging torque is one of the most important parameters of permanent magnet motors, which causes torque ripple, vibration and noise. This paper describes the mechanism of cogging torque, introduces several methods of reducing cogging torque and points out the advantage of novel magnet arrayed permanent magnet motor in reducing cogging torque. Ansoft software is used to build the simulation of conventional surface-type permanent magnet motor and novel magnet arrayed permanent magnet motor and to calculate their cogging torque. a cogging torque testing system which included the angle sensor, permanent magnet motor, torque wrenches and other components are tested two different structures motors’ cogging torque .The experimental result is consistent with the simulation results, it shows that the method of novel magnet arrayed permanent magnet motor reducing cogging torque is correct. The new method compare with the same specification on the surface of permanent magnet motor can reduce more cogging torque.

Abstract: The paper uses empirical mode decomposition to extract the fault feature of gearboxes. Traditional techniques fail to process the non-stationary and nonlinear signals. Empirical mode decomposition is a powerful tool for the non-stationary and nonlinear signal analysis and has attracted considerable attention recently. First, a simulation signal is used to measure the performance of the empirical mode decomposition method. Then, the empirical mode decomposition method is applied to analyze the signals captured from the gearbox with multiple faults and successfully extracts the multiple fault information from the collected signals. The results show that empirical mode decomposition could be a helpful method for mechanical fault feature extraction.

Abstract: An industrial personal computer-based test system for starting relays is presented in this paper, its testing circuit and approaches are mainly introduced. According to the relative standards, the test system can not only measure conversional parameters of relays automatically and accurately, but also detect the performance while their contacts work though a large current. With reliable performance and simple operation, it will play a significant role in production and maintenance of vehicles.

Abstract: The author analyzed the working environment of special hydraulic turbine for cooling tower basing on the difference between the special turbine for cooling tower and the conventional power turbine. The former works in series pressure system and the water head determined by the pipeline resistance and the property of circulating water pump of cooling tower. It is the key to transform the cooling tower system successfully and save energy to build up a series special theories which include the specific speed of turbine for cooling tower, the type of turbine, the parameters selection, the design of the flow passage and runner of turbine by effectively transforming the conventional power turbine theory to the special turbine of cooling tower.

Abstract: The new energy saving pumping unit driven by linear induction motor (LIM) not only can overcome many disadvantages of traditional beam-pumping unit, but also has a lot of advantages, such as reliability, high operating efficiency, etc. So it arouses the universal concern of the oil industry. This paper focuses on the study of linear motor. Firstly, it analyzes the advantages of the pumping unit driven by LIM relative to beam-pumping unit, then in accordance with the system design requirements and based on the electromagnetic design method of linear motor, makes the theoretical calculation and the structure design of the motor, determines specific parameters of LIM, produces LIM applicable to the practical application to drive pumping unit. Lastly, makes field experiments, and experiments results show that LIM has reached the design requirements, also verify the correctness and feasibility of the design method.

Abstract: With superior performances, Linear motor driven pumping unit becomes the electrical control of the focus and emphasis of the recent oil field equipment. Against the beam pumping unit motor efficiency, low power factor and stoke that difficult to regulate, this paper proposes new research programs about energy-saving line pumping systems by linear motor driven source. Paper Studys the mechanical model of linear motor in detail, using MATLAB / SIMULINK, a simulation model is analyzed. At the base of vector control of revolving induction motor, we established the linear motor control system. Theoretical analysis and computer simulation results show that the speed control system has good performance, response characteristics of the electromagnetic force, and demonstrate the proposed mathematical model and control method.

Abstract: In this paper, a time-domain analysis method based on multivariate statistic is presented for wind power generation fault diagnosis. Generally, the sound and vibration signals obtained from wind power generation are time-variant since they are strongly related to the rotational speed which is not constant even in the macro steady state. Since the mostly used signal processing method, the Fourier analysis, is only suitable for stationary signals, the development of the joint time-frequency analysis is demanded. Here, Q statistic (also referred as squared prediction error, SPE) is introduced, it is used to monitor the vibration signals and three-phase currents. The control limit of the Q statistics is calculated to decide the state of the rotating machine, and the contribution plot of SPE is used to find the fault source. The method can efficiently detect faint change and the validity of the method is proved by experiments.

Abstract: The intelligent design technology based on the Expert System (ES) was applied into injection mould design. The experts’ knowledge and experience related to the injection mould project design (IMPD) was expressed in the form of production rule. The knowledge base of intelligent project design of injection mould was constructed. The knowledge automatic reasoning via CLIPS (C Language Integrated Production System) knowledge deducing machine was realized. The achievement of the injection mould project’s intelligent design was reached. The research on the injection mould intelligent design based on CLIPS was made. The intelligent design system for injection mould project (IDSIMP) was developed. The injection mould design project could be provided to the injection mould design engineers via the system. The system is of better application value on engineering.