This block implements some logic for appropriate PWM signal generation for the three half bridges of the motor controller. The actual dutyCycle is updated only when bridgeModeIn[3]
changes, i.e. the motor commutates or an active event occurs.
The PWM period can be either fixed pulseWidth.periodTime = periodPsc / PwmClockFrequency
or variable by setting the parameter PwmVarFrequency
to false or true. When the variable PWM frequency method is selected, the PWM period is calculated by periodPsc = DefaultPeriodPsc / ( 4 * dutyCycle * (1 - dutyCycle))
. So the PWM period is increased when very high or very low duty cycles are applied keeping the current ripple constant at all duty cycles