This paper deals with power quality problems encountered in weak AC microgrids and solutions for mitigation. A power electronic converter can be used as an effective power quality conditioner to compensate non-idealities in currents drawn from the grid. A power quality conditioner consisting of three power converters connected to a common DC link is analysed. One of these converters acts as an active power filter for removing unwanted harmonics in grid currents feeding a non-linear load. The other two converters instead remove the harmonics from the voltage at the terminals of a sensitive load. The control of the shunt converter is designed to be fast enough for power quality servicing but also has a fast disturbance rejection capability. Simulation and experimental results validating the concept are provided along with obtained total harmonic distortion improvements.