@article{BragardSoltauThomasetal.2015,
  author    = {Michael Bragard and N. Soltau and S. Thomas and R. W. De Doncker},
  title     = {The balance of renewable sources and user demands in grids : power electronics for modular battery energy storage systems},
  journal   = {IEEE transactions on power electronics},
  volume    = {25},
  number    = {12},
  pages     = {3049 -- 3056},
  doi       = {10.1109/TPEL.2010.2085455},
  year      = {2015},
}