This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different he...This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different heuristic optimization techniques including PID-PSO, Fuzzy-PSO and GA-PSO to improve the DSIM speed controlled loop behavior. The GA and PSO algorithms are developed and implemented into MATLAB. As a result, fuzzy-PSO is the most appropriate scheme. The main performance of fuzzy-PSO is reducing high torque ripples, improving rise time and avoiding disturbances that affect the drive performance.展开更多
In this paper, responses of a new dual-induction resistivity logging-while-drilling （LWD） tool in 3D inhomogeneous formation models are simulated by the vectorfinite element method （VFEM）, the influences of the bo...In this paper, responses of a new dual-induction resistivity logging-while-drilling （LWD） tool in 3D inhomogeneous formation models are simulated by the vectorfinite element method （VFEM）, the influences of the borehole, invaded zone, surroundingstrata, and tool eccentricity are analyzed, and calibration loop parameters and calibrationcoefficients of the LWD tool are discussed. The results show that the tool has a greater depthof investigation than that of the existing electromagnetic propagation LWD tools and is moresensitive to azimuthal conductivity. Both deep and medium induction responses have linearrelationships with the formation conductivity, considering optimal calibration loop parametersand calibration coefficients. Due to the different depths of investigation and resolution, deepinduction and medium induction are affected differently by the formation model parameters,thereby having different correction factors. The simulation results can provide theoreticalreferences for the research and interpretation of the dual-induction resistivity LWD tools.展开更多
To minimize the reactive power of the converter of the control winding in the novel dual stator-winding induction generator based on the PWM converter, design features of the induction generator with a rectified load ...To minimize the reactive power of the converter of the control winding in the novel dual stator-winding induction generator based on the PWM converter, design features of the induction generator with a rectified load are proposed. The optimization method of excited capacitors to minimize the reactive power of the control winding at a variable speed is given. The calculation capacity of the machine with a diode bridge rectifier load is proposed. To achieve global searching, the integrated method with the improved real-coded genetic algorithm and the twodimensional finite element method （FEM） is introduced. Design results of the sample show that reactive power can be reduced by the method, and the converter capacity can be decreased to 1/3 of output rated power at the speed ratio of 1 ： 3, thus reducing the volume and the mass of the inverter.展开更多
Nature inspired deformable heterogeneous smart hydrogels have attracted much attention in many fields such as biomedicine devices and soft actuators.However,normal spatial heterogeneous hydrogel structures can only re...Nature inspired deformable heterogeneous smart hydrogels have attracted much attention in many fields such as biomedicine devices and soft actuators.However,normal spatial heterogeneous hydrogel structures can only respond to single factor and take one action as set in fabrication.Herein,we report a pre-stretched metal-liganded shape memory hydrogel with fiber reinforced,P(AAc-co-AAm)/CCNFs-Fe3+(CCNFs:carboxylated cellulose nanofibers,AAc:acrylic acid,AAm:acrylamide),which can conduct shape deformation by solvent induction and ultraviolet(UV)light.The deformation pattern could be programmed by the deposing of ferroin ions.Also,the pre-stretched shape memory hydrogels could effectively produce cyclic actuation or complex shape actuation by UV light.More importantly,combining the solvent response with the light response enabled complex reversible actuations,such as simulating the bending and unfolding of fingers.The addition of CCNFs significantly enhanced the mechanical properties of the hydrogels.The hydrogels with 3 wt.%CCNFs showed an elongation at break of about 500%and a significant increase in tensile strength of 8.7-fold to 1.55 MPa after coordination with metal ions,which was able to meet the mechanical requirements of the bionic actuated hydrogels.This work demonstrated that combining light-programmed and light-responsive shape-memory hydrogels,complemented by another independent response property,could achieve complex and reversible programmed actuations.展开更多
The response characteristics of the dual-induction logging tool while drilling in a half-spaceare computed and analyzed when the instrument slots opening direction, instrument height, ground conductivity is changed re...The response characteristics of the dual-induction logging tool while drilling in a half-spaceare computed and analyzed when the instrument slots opening direction, instrument height, ground conductivity is changed respectively. The results show that the haJ^-space response of the different opening direction of instrument slots has a nonlinear change with the increase of the ground conductivity. The effect of half-space response on the instrument slots downward opening direction is greatest and the upward is minimal The half-space response of the deep induction reaches the maximum near the 0.4m height when tool is above ground. The peak position does not change with the ground conductivity changes.These results have a practical significance to determine accurately the sonde error of the dual-induction logging tool while drilling.展开更多
基金Project supported by Faculty of Technology,Department of Electrical Engineering,University of Batna,Algeria
文摘This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different heuristic optimization techniques including PID-PSO, Fuzzy-PSO and GA-PSO to improve the DSIM speed controlled loop behavior. The GA and PSO algorithms are developed and implemented into MATLAB. As a result, fuzzy-PSO is the most appropriate scheme. The main performance of fuzzy-PSO is reducing high torque ripples, improving rise time and avoiding disturbances that affect the drive performance.
基金supported by the National Oil and Gas Major Projects(No.2011ZX05020-002)
文摘In this paper, responses of a new dual-induction resistivity logging-while-drilling （LWD） tool in 3D inhomogeneous formation models are simulated by the vectorfinite element method （VFEM）, the influences of the borehole, invaded zone, surroundingstrata, and tool eccentricity are analyzed, and calibration loop parameters and calibrationcoefficients of the LWD tool are discussed. The results show that the tool has a greater depthof investigation than that of the existing electromagnetic propagation LWD tools and is moresensitive to azimuthal conductivity. Both deep and medium induction responses have linearrelationships with the formation conductivity, considering optimal calibration loop parametersand calibration coefficients. Due to the different depths of investigation and resolution, deepinduction and medium induction are affected differently by the formation model parameters,thereby having different correction factors. The simulation results can provide theoreticalreferences for the research and interpretation of the dual-induction resistivity LWD tools.
文摘To minimize the reactive power of the converter of the control winding in the novel dual stator-winding induction generator based on the PWM converter, design features of the induction generator with a rectified load are proposed. The optimization method of excited capacitors to minimize the reactive power of the control winding at a variable speed is given. The calculation capacity of the machine with a diode bridge rectifier load is proposed. To achieve global searching, the integrated method with the improved real-coded genetic algorithm and the twodimensional finite element method （FEM） is introduced. Design results of the sample show that reactive power can be reduced by the method, and the converter capacity can be decreased to 1/3 of output rated power at the speed ratio of 1 ： 3, thus reducing the volume and the mass of the inverter.
基金funded supported by the Key Research Program of Frontier Sciences of CAS(Nos.ZDBS-LY-SLH036 and QYKJZD-SSW-SLH02).
文摘Nature inspired deformable heterogeneous smart hydrogels have attracted much attention in many fields such as biomedicine devices and soft actuators.However,normal spatial heterogeneous hydrogel structures can only respond to single factor and take one action as set in fabrication.Herein,we report a pre-stretched metal-liganded shape memory hydrogel with fiber reinforced,P(AAc-co-AAm)/CCNFs-Fe3+(CCNFs:carboxylated cellulose nanofibers,AAc:acrylic acid,AAm:acrylamide),which can conduct shape deformation by solvent induction and ultraviolet(UV)light.The deformation pattern could be programmed by the deposing of ferroin ions.Also,the pre-stretched shape memory hydrogels could effectively produce cyclic actuation or complex shape actuation by UV light.More importantly,combining the solvent response with the light response enabled complex reversible actuations,such as simulating the bending and unfolding of fingers.The addition of CCNFs significantly enhanced the mechanical properties of the hydrogels.The hydrogels with 3 wt.%CCNFs showed an elongation at break of about 500%and a significant increase in tensile strength of 8.7-fold to 1.55 MPa after coordination with metal ions,which was able to meet the mechanical requirements of the bionic actuated hydrogels.This work demonstrated that combining light-programmed and light-responsive shape-memory hydrogels,complemented by another independent response property,could achieve complex and reversible programmed actuations.
文摘The response characteristics of the dual-induction logging tool while drilling in a half-spaceare computed and analyzed when the instrument slots opening direction, instrument height, ground conductivity is changed respectively. The results show that the haJ^-space response of the different opening direction of instrument slots has a nonlinear change with the increase of the ground conductivity. The effect of half-space response on the instrument slots downward opening direction is greatest and the upward is minimal The half-space response of the deep induction reaches the maximum near the 0.4m height when tool is above ground. The peak position does not change with the ground conductivity changes.These results have a practical significance to determine accurately the sonde error of the dual-induction logging tool while drilling.
