Slide bài giảng hình vẽ về máy điện rất hay

Positive direction of travel FIGURE 1.14.. Surface element vector for the Aux surface of Figure 1,13.. The positive direction of travel around this surface is indicated by the curved

Máy điện DC

Từ trường trong khe hở không khí

A /

x2

SS

Br B= Br

air gap

FIGURE 1.4 Soft iron cylindrical core placed inside a hollowed out permanent magnet to produce a radial magnetic field in the air gap.

Động cơ đơn giản

FIGURE 1.5 A single-loop motor From Electromagnetic and Electromechanical

Machines, 3rd edition, L W Matsch and J Derald Morgan, 1986 Reprinted by permisson of John Wiley & Sons.

FIGURE 1.7 (a) DC motor with a field winding (b) Radial magnetie 8eld

strength in the air gap produced by the field current

FIGURE 1.8 (a) 0 < 6g < x From Electromagnetic and Electromechanical Ma- chines, 3rd edition, L W Matsch and J Derald Morgan, 1986 Reprinted by permisson of John Wiley & Sons

Positive

direction

of travel

FIGURE 1.14 Surface element vector for the Aux surface of Figure 1,13 The positive direction of travel around this surface is indicated by the curved arrow

FIGURE 1.16 Computation of the inductance of the rotor loop The surface element vector is dS = —rpd@dz? with a resulting positive direction of travel

as indicated by the curved arrow This direction coincides with the direction of

positive current, that is, 1 > 0.

i

=

=

FIGURE 1.17 Left: Rotor loop Right: Equivalent circuit.

FIGURE 1.19 DC motor drawing and schematic

FIGURE 1.27 A multiloop armature for a DC motor.

insulation

FIGURE 1.28 Commutator for the rotor in Figure 1.27.

FIGURE 1.29 Photo of the rotor of a DC motor (left) and its tachometer (right) Note that the slots for the windings of the DC motor are skewed (see problem 9) Photo courtesy of Professor J D Birdweil of the University of Tennessee.

FIGURE 1.30 (a) Rotor loops and commutator for 4 sets of rotor loops Brushes remained fixed in space, that is, they do not rotate From Electric Machinery Fundamentals, 2nd edition by S J Chapman, McGraw-Hill 1991 Reproduced

with permission of McGraw-Hill Companies

Permanent magnet

Permanent magnet

Air gap

(a) (b) (C)

FIGURE 1.31 (a) Stator of a PM DC motor (b) Stator iron (c) Stator perma-

nent magnet

(a) (b)

FIGURE 1.32 (a} Stator iron for a wound field DC motor (b) Cross-sectional

view of the stator iron with the field windings

FIGURE 1.34 Magnetic field distribution due to the armature current Adapted

from Ref [23]

FIGURE 1.35 Magnetic field due to field and armature currents Adapted from FIGURE 1.55 Magnetic field due to both the field and armature currents

Ref, (23)

FIGURE 1.57 Series-connected DC motor Adapted from Ref [21]

FIGURE 1.58 Equivalent circuit for a series DC motor.

FIGURE 1.59 Shunt connected DC motor Adapted from Ref [21j T

FIGURE 1.60 Equivalent circuit for a shunt DC motor.