The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the...The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the high-power shipping during the design stage, the steady-state analysis is as important as the dynamic analysis generally. A mathematical model of the brushless DC propulsion motor is established according to the state-space method for the dynamic and steady-state performance analysis. The state-space mathematical model is a set of linear differential equations, so the steady-state currents of the armature windings can be gained directly by the symmetrical boundary conditions and the eigenvalues of the system matrix. The steady-state simulation results are compared with the dynamic ones to validate the correctness of this eigenvector method.展开更多
In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor （LI...In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor （LIM）. And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM （thrust and normal force, input current, efficiency and power factor）, and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system.展开更多
文摘The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the high-power shipping during the design stage, the steady-state analysis is as important as the dynamic analysis generally. A mathematical model of the brushless DC propulsion motor is established according to the state-space method for the dynamic and steady-state performance analysis. The state-space mathematical model is a set of linear differential equations, so the steady-state currents of the armature windings can be gained directly by the symmetrical boundary conditions and the eigenvalues of the system matrix. The steady-state simulation results are compared with the dynamic ones to validate the correctness of this eigenvector method.
文摘In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor （LIM）. And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM （thrust and normal force, input current, efficiency and power factor）, and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system.
