Seung-Koo Baek, “5상 유도전동기 구동을 위한 인버터의 고장진단 및 허용제어기법,” 아주대학교 공학박사 학위 논문, 2017. > Paper

This paper proposes a fault diagnosis and an improved fault-tolerant control scheme for an open fault in the five-phase inverter driving

system. The five-phase induction machine has the merit of fault-tolerant control compared with the three-phase induction machine 

due to its increased in a number of phases. In this paper, open fault patterns are analyzed using the concept of d-q spaces. The 

trajectory of stationary d-q axis current can be used to verify whether the fault occurs or not according to the each switch situation. In 

order to detect an open fault, two parameters of fault_mag and fault_θ_error are defined. This method can verify the information in 

both the faulted phase and switch position during the one cycle. The fault-tolerant control is used to operate the five-phase induction 

machine under the open fault condition in any phase. Current control using synchronous frame transformation matrix is considered 

under asymmetric phase condition. In addition, re-defined output concept for four healthy phase is proposed. The proposed fault- 

tolerant algorithm contributes to reducing the torque and current ripple at any phase open fault condition. The simulations are carried 

out to analytically approach and verify the effectiveness of the proposed methods for an open switch fault diagnosis and fault-tolerant 

control scheme. Its validity has been proven through the experimental setups using 1.5 kW five-phase induction machine.