The active PFC is simply a boost converter, with the boost voltage chosen to be above the peak rectified AC input voltage.
I've drawn a simple picture below ... I think you are talking about the inductor value for T1, which is coupled to a sense/reset winding.
You are saying you don't know the values of these windings.
The value for the inductor's main winding is chosen like any other boost converter inductor. The PFC controller will control the gate of the switch Q1 to charge the bus capacitor C
bus up to the bus voltage; it will do so while maintaining inductor current to closely follow the voltage cycle of the rectified input. It will gate the voltage onto the DC bus at a high frequency, like 20khz to 50khz, charging the capacitor in small bursts timed with the voltage waveform. This high frequency ripple can be filtered out of the AC line with standard passive AC filtering before the bridge rectifier. I didn't draw the AC line filter here, but I'm sure you've seen them before, and I've even drawn one on the forum in the past,
over here.When the PFC controller's gate is on, the induced voltage in the reset winding is sensed by the PFC controller to determine where in the cycle it is, i.e. the peaks and valleys of the cycle. When the PFC controller switches the gate off, the inductor current collapses in the primary winding and reverses in the reset winding, which is fed back into the PFC controller and used to reset the core.
The datasheet for your chosen PFC controller should show a minimum and maximum voltage allowable for that pin's input. On one datasheet I looked at, this was specified as min -25V, max +25V. So you would size the turns ratio of T1 to ensure that it is no more than 25V referenced to ground, based on what you calculate your primary turns should be, which would be the number of turns required on your chosen core to get the calculated inductor value (for your bus voltage and current)
Does that help?