• fast-switching converters
• high-dynamics systems
• power electronics
• Real-time control
• wide-bandgap semiconductors

Nowadays, power electronics is becoming more and more important in many applications fields, from power systems to industry to transportation to consumer appliances. In fact, on one hand the possibility to adjust power supply for motors and other devices is more and more requested, whereas on the other hand the technology is evolving offering better and better performances in terms of energy efficiency, control capability, compactness and lightweight. Recently, new power devices based on wide bandgap semiconductors permitted to substantially increase the operation frequency by drastically reducing commutation time and thus switching losses. This may turn out highly beneficial both for reducing the size of reactive filter elements and for improving the overall performances, provided that a suited control system is get ready.
One of the applications of fast switching converters consists in operating as active filters to alleviate the problems created in power systems by the presence of non-linear devices also drawing reactive power and possibly unbalanced currents, including older converters such as diodes and SCR based rectifiers. In this thesis, developed in collaboration with the PEMC group of the University of Nottingham, such type of application is addressed referring to a shunt power filter for harmonic current and reactive power compensation in a single-phase AC grid. The converter structure is first defined and analyzed, developing a theoretical model taking into account the system features to obtain a first rough preliminary design. Then, a simulation model is implemented using the PLECS/Simulink software to validate and refine the operation of the active filter, especially focusing on the stability and effectiveness of the the control strategy. Afterwards, the design of a prototype of the converter is finalized, using the Altium software for defining the layout of the PCBs. The manufacturing and assembly of the prototype designed are then described. A suited microcontroller is then selected and programmed to implement the control strategy selected for managing the control of the entire system. Finally, the results obtained from some experimental tests carried out on the prototype active filter are presented and commented.