A Fault-Tolerant Power Conversion Topology for PMSG based Wind Power Systems

This work aims to investigate a novel fault tolerant topology for Permanent Magnet Synchronous Generator (PMSG) based Wind Power Systems (WPS), where the static power converter consists of two three-phase inverters connected in back to back configuration. The first inverter is used to control the PMSG while the other one is used to deliver power to the grid through an output filter and a line frequency transformer. Essentially, the fault tolerance is achieved by performing a cooperative control strategy when a faulty condition occurs in one of the two drives. Whenever a fault occurs in one of these two parts, the faulty elements are isolated, the faulty part is controlled in open phase mode and the resulting current flowing out the neutral point is redirected to the healthy part which is so exploited as a feedback current path. The proposed Fault Tolerant WPS (FTWPS) requires very limited modifications to the vector control performed in the PMSG as well as to the active and reactive power control implemented in the grid side, by keeping similar performance with respect to the healthy system. The theoretical analysis is supported by experimental tests, validating the effectiveness of the system configuration.