Simple model of a sin-cos-resolver, i.e. sensing the angle of
the flange phi (w.r.t. the optional support) and
multiplied by p, providing 4 signals:
y[1] = offset + amplitude*cos(p*(phi - phi0))y[2] = offset - amplitude*cos(p*(phi - phi0))y[3] = offset + amplitude*sin(p*(phi - phi0))y[4] = offset - amplitude*sin(p*(phi - phi0))Thus the sine and cosine signals have p periods per
mechanical revolution. Adding an offset >
amplitude, the loss of one track can be determined.
Subtracting the negated signal from the signal, the offset is
removed and a cosine and a sine with doubled amplitude are
accessible. From this signal, the angle within one pole pair of a
machine can be determined for field oriented control. Block
SinCosEvaluation can be used.
This model can be used to export FMUs of drives to develop control strategies in other environments. When switching to a real drive, the same inputs as from the FMU can be used.
Note that phi0 has to be set that way, that in
shaft position phi0 the flux linkage of phase 1 is a
maximum. In order to sense the mechanical angle of the shaft
p = 1 has to be set.