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A compound DC motor connects the armature and fields windings in a shunt and a series combination to give it characteristics of both a shunt and a series DC motor. [5] This motor is used when both a high starting torque and good speed regulation is needed. The motor can be connected in two arrangements: cumulatively or differentially.
A DC motor consists of two parts: a rotor and a stator. [3] The stator consists of field windings while the rotor (also called the armature) consists of an armature winding. [ 4 ] When both the armature and the field windings are excited by a DC supply, current flows through the windings and a magnetic flux proportional to the current is produced.
In the subject area of control theory, an internal model is a process that simulates the response of the system in order to estimate the outcome of a system disturbance. The internal model principle was first articulated in 1976 by B. A. Francis and W. M. Wonham [1] as an explicit formulation of the Conant and Ashby good regulator theorem. [2]
To translate this model to a rotating motor, one can simply attribute an arbitrary diameter to the motor armature e.g. 2 m and assume for simplicity that all force is applied at the outer perimeter of the rotor, giving 1 m of leverage.
Magnetic field (green) induced by a current-carrying wire winding (red) in a magnetic circuit consisting of an iron core C forming a closed loop with two air gaps G in it. In an analogy to an electric circuit, the winding acts analogously to an electric battery, providing the magnetizing field , the core pieces act like wires, and the gaps G act like resistors.
When an electric motor, AC or DC, is first energized, the rotor is not moving, and a current equivalent to the stalled current will flow, reducing as the motor picks up speed and develops a back EMF to oppose the supply. AC induction motors behave as transformers with a shorted secondary until the rotor begins to move, while brushed motors ...
These apparent advantages of the DTC are offset by the need for a higher sampling rate (up to 40 kHz as compared with 6–15 kHz for the FOC) leading to higher switching loss in the inverter; a more complex motor model; and inferior torque ripple. [1] The direct torque method performs very well even without speed sensors. However, the flux ...
The key feature of the Ward Leonard control system is the ability to smoothly vary the speed of a DC motor, including reversing it, by controlling the field and hence the output voltage of a DC generator, as well as the field of the motor itself. As the speed of a DC motor is dictated by the supplied voltage, this gives simple speed control ...