This Special Section on ?Optimization of Electrical Machine Designs? summarizes the state-of-the-art on the latest researches carried out on the topic, both in the academic and industrial environments. Basically, all the electrical machine topologies and optimization techniques have been discussed in this Section, suggesting to the readers interesting solutions of several optimization problems related with modern applications. The second part of the special section (the first one has been published in the December 2017 issue of the IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS) includes 20 papers from a total of 44 accepted contributions. The studies included in the Part II are categorized in Table I and are hereafter outlined to some extent in order to help the readers to quickly compare the main peculiarities of the mathematical approaches and the practical implementations.