Slip Compensation is a VFD control mode that controls the motor speed by estimating the motor slip according to the applied load.  The output frequency is automatically corrected to compensate for the estimated slip. The slip frequency is calculated based on the programmed motor slip, full load current, and no load current. The output current monitored by the VFD is the variable use for calculating the load and, in turn, increases or decreases the overall slip frequency. Refer to the below variables and formula.

The below diagram shows that as load (current and slip) increase and speed decreases the slip compensation function will increase output frequency in order to overcome the load.