Papers by Author: Yong Ming Yang

Abstract: The electromagnetic radiation emission model of motor drive System for electric vehicles (EVs) is presented in this paper. First, the radiation electromagnetic interference (EMI) mechanism of the motor drive system is analyzed and investigated by experiment. The radiation EMI mainly comes from the common mode current flowing along the three phase cable between the inverter and the motor. Secondly, the feasibility of the finite element method (FEM) is verified by calculating the wire electromagnetic field around and the radiation EMI model of the motor drive system is established using the FEM. The simulation and experimental results show that the proposed model is feasible.

Abstract: Transformer vibration research is an effective diagnosis of DC bias fault. The vibration signal acquired is actually the mix signal of vibration from both the core and windings, and this makes it difficult to analyze the above two separately. Therefore the paper presents a new approach to separate vibration signal of core and windings by Fast-ICA algorithm. The simulated results of core and windings vibration are given and compared with experiment test. Comparative analysis verify that transformer vibration in no-load is core vibration and vibration in short circuit is windings vibration. Transformer vibration signals under different DC bias are tested by experiment. Vibration signals are separated by Fast-ICA algorithm. Core vibration signal and windings vibration signal are respectively obtained. The research lays the groundwork for further research of transformer DC bias vibration.

Abstract: In this paper, the terminal sliding mode (TSM) control technique is used to solve the solution sought for the maximum power point tracking (MPPT) of wind energy conversion system. In order to realize the control strategy, the wind energy conversion system (WECS) is regarded as a part of the constructed high order system. Based on the constant tip-speed ratio (TSR), selecting the appropriate state variables and treating rotational speed as the object researched, the control scheme for the MPPT of wind turbine can be achieved by using the terminal sliding mode control technique. The simulation carried out shows that the system tracking efficiency can be greatly improved and the power factor and tip speed ratio are very close to the optimal value in this solution.

Abstract: The application of the high-voltage supply system and the motor drive system in electric and hybrid-electric vehicles can leads to a significant increase in electromagnetic compatibility. The influence of traction batteries as part of the electromagnetic interference path must be considered. In this paper models of single cell, cells connected in series and cells connected in parallel are developed based on the measured impedance curve of single cell, the models are formulized in the frequency domain and verified by impedance measurement on Ni-MH batteries, the results allow the simulation of batteries as interference path and the prediction of external electric fields and magnetic fields.

Abstract: Currently specific discharge point cannot be effectively located using common electrometric methods of generator stator winding partial discharge online monitoring. To solve the problem an electrical-sound joint detection method has been proposed. Since accuracy of location would be heavily affected by time delay of ultrasonic wave propagation, background noise and spectrum of partial discharge ultrasonic signal were analyzed first, and ultrasound field distribution and ultrasonic wave propagation were also stimulated. Moreover, an ultrasonic sensors distribution method was proposed to reduce the delay estimation error. The method was verified by field experiments. Experimental results showed that the theoretical analysis was exact and the sensor distribution method was feasible, thus laying foundation for further realizing large generator partial discharge Ultrasonic wave on line monitoring and location.

Abstract: Video-oculography (VOG) is a non-invasive method used for the eye tracking detecting. A most important work of VOG is to accurately estimate the pupil center. However, VOG cannot acquire eye movement when the eye blinks. A Grey forecasting model was proposed to predict the pupil center for the blinking frame of VOG video. The Grey forecasting model used GM(1,1) model to carry on the modeling. Then an experiment is provided. The experiment results show that the predicted data of the Grey forecasting meet the characteristics of the patients with nystagmus. The Grey forecasting model is a viable means of accurately predict the pupil center for blinking in VOG.

Abstract: When do research on the location of partial discharge in power generator’s stator using ultrasonic sensor, there are many problems exist including that ultrasonic signals detection is not obvious or even ultrasonic sensor can not detect ultrasonic signals. This article researches the location distribution in power generator which is favorable for ultrasonic sensor to receive ultrasonic signals. Put forward a placement method of sensor which is applies to the partial discharge location of power generator basing on sonic pressure distribution of ultrasonic signal in the stator’s outer, which is obtained by simulating sound field of power generator stator using ANSYS Multiphysics. The placement method of sensor has laid the foundation for the future research of the partial discharge location of power generator. Through comparing the simulation results and actual experimental test, the authors find that simulation of sonic pressure is similar to experimental results, proving the placement method is validity.

Abstract: In this paper, a remote Distribution Transformer (DT) monitoring system is presented and developed to solve the problems of existing remote monitoring system wiring too much, too complicated, fault diagnosing and maintaining difficulty. The system hardware design based on 16 bit PIC18F458 chip and GSM module TC35i is proposed. The system software design with MySQL and Visual C++6.0 are discussed in detail. A real-time monitoring of parameters such as three-phase voltage, current, power factor and transformer temperature is finally realized. Experiment results show that the system possesses accurate data gathering, strong anti-interference and good operation performance.