Predictive Control applied in 4 Leg NPC Inverters

Power electronics applications started with the purpose of driving electric motors. The nature of this application generally implies no need of a neutral cable. In consequence classic inverters have three legs, one for each phase. However, in medium and low voltage energy distribution, it is common to use three phases plus a fourth neutral wire. This case becomes especially relevant for renewable energy and distributed generation. The use of three leg inverters for four wire applications has a number of drawbacks which could be improved by using the four leg NPC topology. In this book these improvements are explained and tested using a predictive controller. The experimental results are presented, as well as the description of the hardware and firmware which was implemented. The analyses presented in this book might be interesting for exploring the application of multilevel topologies in energy distribution. It is also useful as an implementation example of predictive control in power electronics.