**Acknowledgements**

The author wishes to thank his CPqD colleagues Claudio Floridia, Danilo C. Dini, Rivael S. Penze, Fabio R. Bassan, and João P. V. Fracarolli. Many PoF projects cited in this work were funded by ANEEL (Brazilian Electricity Regulatory Agency). CNPq (National Counsel of Technological and Scientific Development) sponsors the author under scholarship DT.
