SENSORLESS FIELD ORIENTED CONTROL OF BRUSHLESS ...

General Electromechanical Models
There are essentially only two pieces missing from the complete electromechanical model of a
three-phase motor: the contribution of the other two phases and the mechanical model. First, we
only consider a single phase, as the earlier parts of this chapter have done. The electromechanical
simulation diagram for a motor with only one phase, plus its mechanical load, can be obtained by
examining Figure 2.18 (Equation 2.25), Figure 2.23 (Equation 2.34), and Figure 2.25 (Equation
2.39). This is shown in Figure 2.27, where the variables are as follows:
R armature resistance
L self inductance (Figure 2.27)
Ls synchronous inductance (Figure 2.28)
b friction (rotor & load)
J inertia (rotor & load)
v applied terminal voltage
i armature current
T developed electromagnetic torque
TL load torque (rotor & load)
ω rotational velocity
In all block diagrams in this report, the polarity of a vector or signal is always shown to the
arrow’s own left.
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