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AC Motors and Generators
Published in Muhammad H. Rashid, Ahmad Hemami, Electricity and Electronics for Renewable Energy Technology, 2017
The electromotive force (voltage) generated in a motor winding is called back electromotive force (BEMF) or counter electromotive force (CEMF). If this BEMF in a single-phase motor (or each phase of a three-phase motor) is represented by E, and the voltage applied to a motor is denoted by V, then using Ohm’s law, we have V−E=ZI where Z is the impedance of the winding. The BEMF greatly reduces the net voltage across the winding and the current through the winding. Value of E depends on motor speed (as well as other parameters) and becomes larger as speed increases. If the rotor is prevented from turning, then E drops to 0.
Power System Fundamentals
Published in Stephen W. Fardo, Dale R. Patrick, Electrical Power Systems Technology, 2020
Stephen W. Fardo, Dale R. Patrick
The property of inductance (L) is very commonly encountered in electrical power systems. This circuit property, shown in Figure 2-11A, adds more complexity to the relationship between voltage and current in an AC circuit. All motors, generators, and transformers exhibit the property of inductance. The occurrence of this property is due to a counter electromotive force (cemf), which is produced when a magnetic field is developed around a coil of wire. The magnetic flux produced around the coils affects circuit action. Thus, the inductive property (cemf) produced by a magnetic field offers an opposition to change in the current flow in a circuit.
Power System Fundamentals
Published in Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo, Electrical Power Systems Technology, 2021
Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo
The property of inductance (L) is very commonly encountered in electrical power systems. This circuit property, shown in Figure 2-11A, adds more complexity to the relationship between voltage and current in an AC circuit. All motors, generators, and transformers exhibit the property of inductance. The occurrence of this property is due to a counter electromotive force (cemf), which is produced when a magnetic field is developed around a coil of wire. The magnetic flux produced around the coils affects circuit action. Thus, the inductive property (cemf) produced by a magnetic field offers an opposition to change in the current flow in a circuit.
A new fractional-order developed type-2 fuzzy control for a class of nonlinear systems
Published in International Journal of Systems Science, 2021
Akram Sedaghati, Naser Pariz, Mehdi Siahi, Roohollah Barzamini
The mathematical of voltage balance of three-phase winding are given as where , and are voltages of the stator phase winding, represents the resistance of stator phase winding, , and are the stator phase winding currents, , and are the stator phase winding counter electromotive force, L represents phase winding self-induction and M is the mutual inductance between two phases. The dynamics of speed is given as follows: where u is the control signal, B is the coefficient of viscous friction, P represents the number of pules, J is the inertia moment of rotor, f and are defined as follows: where is the load torque and is the permanent magnet linkage flux. The parameters are given in Table 5. The other parameters are same as Example 7.1.
On dealing with harmonic uncertainties in the class of active disturbance rejection controllers
Published in International Journal of Control, 2021
Momir R. Stanković, Rafal Madonski, Sally Shao, Davorin Mikluc
A cascade combination of the converter and the motor parts (assuming motor nonzero armature inductance), illustratively depicted in Figure 10, results in a following average dynamic model of the considered buck converter-fed DC motor system: where is the duty cycle (system input), v [V] is the output capacitor voltage, i [A] is the current across the inductor, R [Ω] is the output load resistance, L [H] is the inductance of the input circuit, C [F] is the capacitance of the output filter and E [V] is the value of external voltage source, [rad/s] is the angular velocity of the motor shaft (system output), which may be subject to an unknown (possibly nonlinear and time-varying) torque perturbation input τ [Nm], [V] is the motor armature voltage, [A] is the armature current, [V/A-rad/ s] is the constant due to counter-electromotive force, [V/A-rad/ s] is the motor torque constant, [H] is the armature inductance, [Ω] is the armature resistance, J [kg·m] is the rotor and load inertia, and [Nm/rad/ s] is the viscous friction coefficient.
Variational approach for robust design and sensitivity analysis of mechatronic systems
Published in Journal of the Chinese Institute of Engineers, 2020
Hana Siala, Faïda Mhenni, Jean-Yves Choley, Maher Barkallah, Jamel LouatI, Mohamed Haddar
Moreover, the electric motor performs electromechanical power conversion between the electrical and rotational mechanical domains. In fact, Equations (9) and (10) are used to express the electromechanical coupling. The current in the motor winding creates a Laplace force, which is reflected by a motor torque . Equation (10) expresses the relationship between the angular speed and the counter- electromotive force E.