A suitable control technique for fault-tolerant converters in Distributed Generation

The penetration of Distributed Generation (DG) in power systems is deeply changing the existing distribution networks which is becoming a very sophisticated and complex systems incorporating both active (generators) and passive systems (distribution systems, converters and loads). The necessary simplification can be obtained dealing with small networks, namely Micro-Grids, reproducing, in a smaller scale, the structure and the problems of large networks including production, transmission and distribution of the electrical energy. In order to achieve an adequate level of reliability, fault-tolerant operations of micro-grids become very important. This result can be achieved only using power converters with fault-tolerance capabilities. Therefore, this paper, presents a control algorithm for fault tolerant converters suitable for micro-grids. After describing the model of the power converter reformulated in terms of healthy leg binary variable, the paper shows how this control preserves power quality when the converter works in the linear range. The effectiveness of the proposed approach is shown through computer simulations.