1,720,981 research outputs found
Speed and Position Estimation for PM Synchronous Motor with Back-EMF Observer
No full textThis paper presents a sensorless scheme for PM synchronous motors, based on back-EMF observer. It provides full analytical description of the back-EMF observer, and the calculation of the position estimation error, taking into account the variation of the electrical parameters of the motor, i.e. stator resistance and synchronous inductance, and the variation of the feeding voltage. The knowledge of such characteristics could be used to improve the performance and the robustness of the sensorless drive by a specific real-time compensation mechanism. Verifications and comparisons are carried out in three steps: a) a time-continuous simulation model (using Matlab-Simulink) is developed to confirm the analytical results; b) a real time simulator of the sensorless drive is used, to evaluate the influence of the time-discrete implementation; c) an experimental BSP based implementation is used to compare actual results
Sensorless Control of Permanent Magnet Synchronous Motors with Luenberger Observer: Theoretical Issues and Implementation
No full textStima di velocità e posizione per motori sincroni a magneti permanenti mediante osservatore di back-EMF
No full textSensorless Control of PM Synchronous Motors with Luenberger Observer: Theoretical Issues and Implementation Results
No full textSpeed and Position Estimation for PM Synchronous Motor with Back-Emf Observer
No full textThis paper presents a sensorless scheme for PM synchronous motors, based on back-EMF observer. It provides full analytical description of the back-EMF observer, and the calculation of the position estimation error, taking into account the variation of the electrical parameters of the motor, i.e. stator resistance and synchronous inductance, and the variation of the feeding voltage. The knowledge of such characteristics could be used to improve the performance and the robustness of the sensorless drive by a specific real-time compensation mechanism. Verifications and comparisons are carried out in three steps: a) a time-continuous simulation model (using Matlab-Simulink) is developed to confirm the analytical results; b) a real time simulator of the sensorless drive is used, to evaluate the influence of the time-discrete implementation; c) an experimental DSP based implementation is used to compare actual results
Speed and Position Estimation for PM Synchronous Motor using self-compensated Back-EMF Observers
No full textPrecise motion control requires high-accuracy and highbandwidth feedback speed information, often calculated by direct measurement of the rotor position available through the incremental encoder equipping the drive. The resolution of the encoder heavily affects the cost of the drive and the accuracy and bandwidth of the calculated speed. The limitations introduced by a low resolution encoder can be partially reduced by a proper speed calculation (or estimation) algorithm, that therefore plays a key role in modern drive systems. In this paper a comparative analysis of state of-art speed measurement and estimation algorithms suitable for low-resolution incremental encoder equipped drives is presented, aiming at highlighting the specific feature of each one, both from the performance point of view, and from the computational requirements needed for actual implementation. The paper proposes itself as a guide for engineers in the complex choice of the best solution for each application
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Extended Torque-Speed Region Sensor-Less Control of Interior Permanent Magnet Synchronous Motors
No full textIn this paper a sensor-less speed controller for an Interior Permanent Magnet synchronous motor is presented. It allows to fully exploit the torque-speed characteristic of the motor, also in the flux-weakening region. It is based on the estimation of a generalized back-EMF space vector by means of a Luenberger state and disturbance observer. The estimated rotor-magnet position and speed are then employed inside an optimised vector control scheme of direct and quadrature motor currents trajectories. Test results are presented, in order to verify the performance and demonstrate the effectiveness of the proposed solution
Speed and Position Estimation for PM Synchronous Motor using Self-Compensated Back-EMF Observers
No full textThe paper deals with the self-compensation of the intrinsic estimation error in back-EMF based rotor position observers for PM synchronous motors. The self-compensation is based on the analytical calculation of the rotor position estimation error for two types of popular back-EMF observers, such as the standard-linear Luenberger observer and the nonlinear sliding mode observer. Once the compensation characteristics are derived, they are included in the observer itself by a proper mechanism in order to cancel the position error affecting the estimation, thus providing the real-time self-compensation scheme. As a consequence, the performance and the robustness of the transducer-less drive can be improved, both at steady state and transient operations. Test results are presented to verify the effectiveness of the method in several operating conditions: both simulation results using a time-continuous Matlab/ Simulink model, and experimental results using a DSP based transducer-less driv
- …
