Primary drivers behind the widespread integration of renewable energies comprise a marriage of the ever-increasing energy demand and a desire for the reduction of carbon footprints. Since renewables are normally coupled to power grids through power electronic converters, power systems gradually evolve into more-electronics power systems. Despite clear efficiency and control benefits, power electronics can bring in concerns to power systems. For one hand, it is difficult to ensure high-quality power supplies. For the other hand, power electronics may introduce instability issues. this report aims to investigate and address several power quality and stability challenges in the hope of smoothing the transformation towards future smart grids. As the trend of renewable integration continues, new challenges and opportunities will emerge in more-electronics power systems. In this report, potential future research directions will be pointed out.