The analysis of salient
pole synchronous motor is based on the Blondel’s two reaction. The
direct and quadrature axis components of current and reactance are same
as defined earlier for the synchronous generators. Thus,
Xd = Direct axis reactance
Xq = Quadrature axis reactance
Id = Direct axis component of Ia
Iq = Quadrature axis component of Ia
The complete phasor diagram of lagging p.f. is shown in the Fig. 1.
|Fig. 1 Phasor diagram for lagging p.f.|
From the phasor diagram it can be derived that,
Note : For the proof of above results refer example 2.
The complete phasor diagram of leading p.f. is shown in the Fig. 2.
|Fig. 2 Phasor diagram for leading p.f.|
For this leading p.f. case,
Note : ? should be taken negative for the leading power factor for calculating other parameters.
While the mechanical power developed per phase is given by,
Total Pm = 3 x Pm
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