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