Open-phase fault-tolerant control of encoderless Y-connected 3-phase induction motors

In encoderless vector control (VC) systems for 3-phase induction motor (IM_3P) drives, an open-phase fault (F_OP) may lead to degradation or shut-down of the drive. An open-phase fault-tolerant control (FTC) for encoderless Y-connected IM_3P drives is proposed in this paper. The FTC is realized based on a modified indirect rotor VC strategy and a developed model reference adaptive system (MRAS). In this paper also the small signal perturbation stability of the MRAS estimator is shown. The proposed scheme by only changing in the control parameters, control variables, and transfer matrices can be utilized for encoderless VC of Y-connected IM_3P drives under normal and F_OP conditions. The effectiveness of the suggested FTC is verified by experiments on a 1HP Y-connected IM_3P drive platform. The experimental results approve that the proposed encoderless FTC system during the F_OP has a better performance compared to conventional encoderless control systems.