Collection of selected, peer reviewed papers from the 2015 9th international power engineering and optimization conference (PEOCO2015), march 18-19, 2015, melaka, malaysia. The 141 papers are grouped as follows: chapter 1: applications of artificial intelligence in power engineering; chapter 2: electrical drives and power electronics; chapter 3: electrical machines and apparatus;chapter 4: quality and reliability of power, protection and electromagnetic compatibility in power systems; chapter 5: planning, operation and economics of power systems; chapter 6: energy policy and engineering management of renewable energy systems;chapter 7: applied decisions in energy and power research
{{comment.content}}