The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
M A Rahman - One of the best experts on this subject based on the ideXlab platform.
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starting performances of delta modulated inverter fed Submersible induction Motors
IEEE Transactions on Industry Applications, 1992Co-Authors: M A Choudhury, M A RahmanAbstract:An analysis of the starting performance of tuned delta-modulated inverter-fed Submersible Motors is presented. Submersible Motors are induction Motors having unique constructional features. These Motors are required to operate in one of the harshest environmental conditions. The operating characteristics of a Submersible motor pump system require a soft starting facility and variable speed operation. To satisfy both requirements, a delta-modulated inverter supply is proposed, and its starting performance is presented. The soft starting characteristic of the motor was obtained by the inherent V/f, control of the delta-modulated inverter. The analysis was carried out using time domain representation of inverter voltages and the d-q axis model of the motor. The time domain representation of inverter voltages was done using gate functions. The starting performances of the Submersible motor improved substantially. Although the analysis and results presented are for a Submersible model, these are equally applicable for any type of polyphase induction motor. >
M A Choudhury - One of the best experts on this subject based on the ideXlab platform.
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starting performances of delta modulated inverter fed Submersible induction Motors
IEEE Transactions on Industry Applications, 1992Co-Authors: M A Choudhury, M A RahmanAbstract:An analysis of the starting performance of tuned delta-modulated inverter-fed Submersible Motors is presented. Submersible Motors are induction Motors having unique constructional features. These Motors are required to operate in one of the harshest environmental conditions. The operating characteristics of a Submersible motor pump system require a soft starting facility and variable speed operation. To satisfy both requirements, a delta-modulated inverter supply is proposed, and its starting performance is presented. The soft starting characteristic of the motor was obtained by the inherent V/f, control of the delta-modulated inverter. The analysis was carried out using time domain representation of inverter voltages and the d-q axis model of the motor. The time domain representation of inverter voltages was done using gate functions. The starting performances of the Submersible motor improved substantially. Although the analysis and results presented are for a Submersible model, these are equally applicable for any type of polyphase induction motor. >
Xiaohua Bao - One of the best experts on this subject based on the ideXlab platform.
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efficiency improvement for Submersible Motors by optimizing the ratio of diameter to shaft length
IEEE Transactions on Magnetics, 2021Co-Authors: Xiaohua BaoAbstract:Aiming to improve the efficiency of the water-filled Submersible motor, the method of optimizing the ratio of diameter to shaft length and air-gap length of the motor is proposed to reduce the water friction loss of the water-filled Submersible motor. By analyzing the composition of the mechanical loss and the research status of the water friction loss of the water-filled Submersible motor, the optimization methods of the water-filled Submersible motor efficiency are determined. Two-dimensional time-harmonic field solutions are employed in this paper to accurately estimate the electromagnetic performance of the Submersible motor, which costs less time and computational resources compared to the transient solution. By fitting the curves of water friction loss and electromagnetic losses with the optimized parameters, the influence of the ratio of diameter to shaft length and the length of the air-gap on the efficiency of the motor is analyzed. Finally, the parameters of the motor are determined, with the consideration of the influence of the radial to axial ratio and the air-gap length on the performance parameters of the motor and the requirements of actual working conditions. The results show that the two methods can effectively reduce the water friction loss of the water-filled Submersible motor and improve the efficiency of the water-filled Submersible motor in the motor design stage.
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analysis of electromagnetic stiffness in Submersible Motors with inclined rotor eccentricity
International Conference on Electrical Machines and Systems, 2014Co-Authors: Yong Fang, Na Liang, Xiaohua BaoAbstract:The electromagnetic stiffness is an important parameter in electromechanical coupling system, and it depends on whether there is eccentricity in motor air-gap. In this paper, the electromagnetic stiffness is proposed. The slipping surface technique is cited. The Submersible Motors with inclined rotor is applied, and the influence of eccentricity rotor on electromagnetic stiffness is calculated theoretically and compared by finite element simulation, based on which the calculation modeling of electromagnetic stiffness is built. Furthermore the distribution of magnetic field energy as well as electromagnetic stiffness along the machine axis, in the Submersible Motors with inclined rotor, is obtained. The variation of magnetic field energy with eccentricity angle reflecting eccentricity level, and the relationship between electromagnetic stiffness and inclined angle alpha, are obtained respectively. Finally the reliability of model by comparing the simulation results with numerical analysis is presented. The investigation in this paper supports references in the eccentricity fault diagnosis for Submersible Motors and theoretical basis for study of rotor dynamics.
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influence of thermal expansion on eccentricity and critical speed in dry Submersible induction Motors
Journal of Electrical Engineering & Technology, 2014Co-Authors: Xiaohua BaoAbstract:Rotor eccentricity is one of the major factors that directly influence the security of horizontal electrical machines, and the critical speed of the shaft has a close relationship with vibration. This paper deals with the influence of thermal expansion on the rotor eccentricity and critical speed in large dry Submersible Motors. The dynamic eccentricity (where the rotor is still turning around the stator bore centre but not its own centre) and critical speed of a three-phase squirrel- cage Submersible induction motor are calculated via hybrid analytical/finite element method. Then the influence of thermal expansion is investigated by simulation. It is predicted from the study that the thermal expansion of the rotor and stator gives rise to a significant air-gap length decrement and an inconspicuous slower critical speed. The results show that the thermal expansion should be considered as an impact factor when designing the air gap length.
Yahui Zhang - One of the best experts on this subject based on the ideXlab platform.
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comprehensive diagnosis of rotor faults of Submersible Motors on offshore platforms
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai Yang, Fan YangAbstract:Aiming at the problem of the harsh operating environment and frequent failures of key electrical components of offshore platforms, this paper proposes a new method for diagnosing rotor faults of Submersible Motors by combining current signals, radial electromagnetic force signals, and unbalanced magnetic pull signals, and combining notch technology to eliminate spectrum leakage. Through real-time monitoring of fault characteristic frequency signals, the running status of the motor can be judged, which is convenient for timely repair and replacement of equipment, and improves the operational reliability of offshore power systems.
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detecting broken bars in Submersible Motors under variable frequency power supply and harmonic management of power grid
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai Yang, Fan Yang, Yifei ZhengAbstract:Aiming at the problem of frequent broken bars of Submersible Motors powered by variable frequency power supply and generating harmonics to the power grid, this paper presents a comprehensive diagnostic method based on the current spectrum of the grid side, the rectifier DC side and the motor stator side and uses the active power filtering scheme to perform harmonic compensation on the grid-side current to improve grid quality. The simulation model is built in MATLAB / Simulink to verify the effectiveness of the proposed method.
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dynamics analysis of rotary shafts of Submersible Motors on offshore platforms
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai YangAbstract:Aiming at the problem that the slender shaft structure of the motor in the electric Submersible pump can easily cause system resonance during the oil production process, this paper uses modal analysis to improve the mechanical structure of the shaft, and then draws a Campbell diagram and performs stress analysis on the improved shaft structure, which can extend the life of the Submersible motor.
Kai Yang - One of the best experts on this subject based on the ideXlab platform.
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comprehensive diagnosis of rotor faults of Submersible Motors on offshore platforms
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai Yang, Fan YangAbstract:Aiming at the problem of the harsh operating environment and frequent failures of key electrical components of offshore platforms, this paper proposes a new method for diagnosing rotor faults of Submersible Motors by combining current signals, radial electromagnetic force signals, and unbalanced magnetic pull signals, and combining notch technology to eliminate spectrum leakage. Through real-time monitoring of fault characteristic frequency signals, the running status of the motor can be judged, which is convenient for timely repair and replacement of equipment, and improves the operational reliability of offshore power systems.
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detecting broken bars in Submersible Motors under variable frequency power supply and harmonic management of power grid
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai Yang, Fan Yang, Yifei ZhengAbstract:Aiming at the problem of frequent broken bars of Submersible Motors powered by variable frequency power supply and generating harmonics to the power grid, this paper presents a comprehensive diagnostic method based on the current spectrum of the grid side, the rectifier DC side and the motor stator side and uses the active power filtering scheme to perform harmonic compensation on the grid-side current to improve grid quality. The simulation model is built in MATLAB / Simulink to verify the effectiveness of the proposed method.
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dynamics analysis of rotary shafts of Submersible Motors on offshore platforms
International Conference on Electrical Machines and Systems, 2020Co-Authors: Yahui Zhang, Kai YangAbstract:Aiming at the problem that the slender shaft structure of the motor in the electric Submersible pump can easily cause system resonance during the oil production process, this paper uses modal analysis to improve the mechanical structure of the shaft, and then draws a Campbell diagram and performs stress analysis on the improved shaft structure, which can extend the life of the Submersible motor.
