This review article is mainly oriented to the control and applications of modular multilevel converters (MMC). The main topologies of the switching modules are presented, for normal operation and for the elimination of DC faults. Methods to keep the capacitor voltage balanced are included. The voltage and current modulators, that are the most internal loops of control, are detailed. Voltage control and current control schemes are included which regulate DC link voltage and reactive power. The cases of unbalanced and distorted networks are analyzed, and schemes are proposed so that MMC contribute to improve the quality of the grid in these situations. The main applications in high voltage direct current (HVDC) transmission along with other medium voltage (MV) and low voltage (LV) applications are included. Finally, the application to offshore wind farms is specifically analyzed.

Project-based learning (PBL) and cooperative learning are, in various aspects, very superior education methodologies compared to other traditional ones. They are highly appropriate methodologies for elective courses, as they exert a strong attraction on the students, quite apart from their educational advantages. This paper describes how PBL and cooperative learning have been used to teach the topics of power supplies and photovoltaic electricity within two elective undergraduate courses. A project is carried out for each of the two topics. Moodle is used as the e-learning platform to provide the course materials and the wiki resource and to allow the submission of assignments. The simulation is done by means of Simulink. Work has been done to develop skills for project planning, group management of the work, technical document writing and presentations in public. The methodology has been seen to be successful, as all the students who have followed it over the last few years have passed the courses in which it was included, Design of Industrial Applications and Industrial Electronics. Examples of the rubrics for assessing the projects and examples of the projects themselves are also included.

This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results are analyzed by comparison to previous academic years and by satisfaction surveys. The new course design applies the jigsaw cooperative learning strategy to have students learn the theory of converters, solve problems, and perform simulations, before carrying out projects that solve real-world problems, such as the power converter for a competition solar vehicle (2014/15 course) and power converters for an air conditioner with inverter technology (2015/16 course). Rubrics were used to evaluate the students' work reports and the simulations. The project deliverables are presented and assessed in two design reviews, the first version covering the design and an open loop simulation, and the second covering the closed loop simulation and verification of specifications.