Post-Fault Compensation Control Strategy for Multi-Three-Phase PMSM under Open-Circuit and Short-Circuit Condition

This paper presents two post-fault compensation strategies for the distributed current control of a nine-phase Permanent-Magnet Synchronous Machine (PMSM). The dynamic performance in faulty condition is guaranteed by keeping the current loop bandwidths constant. The two faults under investigation are Open-Circuit (OC) and Short-Circuit (SC) of one set of the three-phase windings. The decoupled mathematical model of the machine in post-fault conditions are derived prior to the control strategies are designed. The Vector Space Decomposition (VSD) is used and the design for the controllers is revised. While short-circuiting one set of three-phase windings, in order to eliminate different electromagnetic interactions, different lag compensators for different healthy modules are introduced. The proposed post-fault control strategies are compared against the step response in nominal condition and further validated by means of Matlab/Simulink (R) simulations, where three Two-Level Three-Phase Voltage Source Inverters (2L-3P-VSIs) are used to supply the machine.