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UAS Subsystem Nexus
Published in R. Kurt Barnhart, Douglas M. Marshall, Eric J. Shappee, Introduction to Unmanned Aircraft Systems, 2021
Michael T. Most, Samuel Stewart
In a brushed motor design, the (stationary) stator field may be produced using either permanent magnets or multiple turns of current carrying wire to wind the field poles or field pieces. The stator field remains stationary. The timing of the switching operation that controls the orientation of the magnetic field associated with the rotor is accomplished by a mechanical device known as the commutator. The commutator is divided into discrete segments, electrically insulated by a dielectric material such as mica. Opposing segments (i.e., located 180° apart on the commutator) are the terminating points of the ends of one winding. Stationary carbon brushes convey current from the external power source to the armature windings by contacting commutator segments. As current flows into one segment and out of the opposing one, a magnetic field is created in the rotor (armature) winding and oriented in such a way that the interacting attractive and repulsive magnetic forces of the armature and stator fields cause the rotor to develop torque. As the armature rotates, the brushes contact another pair of commutator segments to energize the windings. The direction of the current flow and polarity and orientation of the associated magnetic fields are controlled by the commutation process in such a way that a torque force develops to rotate the armature on its bearings.
Energy Conservation Measures for Wastewater Treatment
Published in Frank R. Spellman, Fundamentals of Public Utilities Management, 2020
The driving torque of both direct current (D-C) and A-C motors is derived from the reaction of current-carrying conductors in a magnetic field. In the D-C motor, the magnetic field is stationary and the armature, with its current-carrying conductors, rotates. The current is supplied to the armature through a commutator and brushes. In induction motors, the rotor currents are supplied by electromagnet induction. The stator windings, connected to the A-C supply, contain two or more out-of-time-phase currents, which produce corresponding magnetomotive forces (mmfs). These mmfs establish a rotating magnetic field across the air gap. This magnetic field rotates continuously at constant speed regardless of the load on the motor. The stator winding corresponds to the armature winding of a D-C motor or to the primary winding of a transformer. The rotor is not connected electrically to the power supply.
UAS Subsystem Nexus: The Electrical System
Published in Douglas M. Marshall, R. Kurt Barnhart, Eric Shappee, Michael Most, Introduction to Unmanned Aircraft Systems, 2016
In a brushed motor design, the (stationary) stator field may be produced using either permanent magnets or multiple turns of current carrying wire wound the field poles or field pieces. The stator field remains stationary. The timing of the switching operation that controls the orientation of the magnetic field associated with the rotor is accomplished by a mechanical device known as the commutator. The commutator is divided into discrete segments, electrically insulated by a dielectric material such as mica. Opposing segments (i.e., located 180° apart on the commutator) are the terminating points of the ends of one winding. Stationary carbon brushes convey current from the external power source to the armature windings by contacting commutator segments. As current flows into one segment and out of the opposing one, a magnetic field is created in the rotor (armature) winding and oriented in such a way that the interacting attractive and repulsive magnetic forces of the armature and stator fields cause the rotor to develop torque. As the armature rotates, the brushes contact another pair of commutator segments to energize the windings. The direction of the current flow and polarity and orientation of the associated magnetic fields are controlled by the commutation process in such a way that a torque force develops to rotate the armature on its bearings.
Practical torque sensorless super-twisting control of manipulators based on a novel integral non-singular fast terminal sliding mode with fixed-time convergence
Published in Advanced Robotics, 2023
Mohammad Yazdani, Soheil Ganjefar
is the applied voltage to armature or system control input (V), is the armature resistance , L is the armature inductance (H), is the back electromotive force (V), is the armature current (A), is the rotor position (rad), is the angular speed of the rotor (rad/s), is the motor torque (N/m), is the load torque (N/m), and is the stator-induced magnetic flux (Wb). The differential equation of the above circuits is as follows:
Power loss and efficiency analysis of an onboard three-level brushless synchronous generator
Published in International Journal of Electronics, 2021
Kai Xiong, Yunhua Li, Yun-Ze Li, Ji-Xiang Wang
In order to conduct the power loss and efficiency analysis for a three-level brushless synchronous generator (TLBLSG), models which are used to accurate calculate the fundamental electrical parameters such as voltages, currents, and magnetic flux have been established. Specifically, the electrical parameters in MG are determined by a back iteration algorithm which combines an analytical model of the MG stator loading with a three-phase diode bridge rectifier (TPDBR) and a capacitor, an equivalent circuit model of the MG, and an estimation model of steady-state excitation current based on the open circuit characteristic (OCC). The ME rotor current and PE stator armature current are obtained by a model of induced electromotive force with a TPDBR and an inductance. All the obtained electrical parameters can reflect the speed and load change as well as saturation influence. On the basis of these models, electrical performances of the TLBLSG under different speeds and loads have been investigated and discussed. The main conclusions can be summarised as follows:
Field-programmable analogue arrays for the sensorless control of DC motors
Published in International Journal of Electronics, 2018
J. Rivera, I. Dueñas, S. Ortega, J. L. Del Valle
where is the rotor velocity, i is the armature current, is the load torque, v is the armature input voltage, is the torque constant, j is rotor inertia, is the back-electromotive-force constant, and R and L are the armature resistance and inductance, respectively. The following assumptions related to the mechanical equation will be used in the control design: The load torqueis a smooth, bounded and slowly varying signal (Utkin et al., 2009), such thatand.The rotor velocityis a bounded signal, such that.