For a Voltage Source Inverter (VSI), an LCL filter is one of the preferred filter methods for obtaining a close to pure sinusoidal output. Even though the LCL filter itself generate harmonic distortion in the output, many methods have been investigated to counteract this distortion. The method of using a damping resister in series with the LCL filter capacitor has proven effective, but at the cost of a significant amount of power losses. In this project three active damping methods, PR control, Notch filter and Virtual Resistor, are studied, and the Virtual Resistor chosen to replace the damping resistor. A PI controller and the Virtual Resistor is designed and tested, both through simulations and lab. testing, and the LCL filter model is subsequently validated. Meanwhile the concept of Adaptive Virtual Resistance is also explored, and a algorithm for Minimal Distortion Tracking is developed and tested through simulations.