Diagnosis and fault-tolerant control of 3-phase AC-DC PWM converter system

摘要

There is a possibility of open-switch fault of 3-phase AC-DC PWM (Pulse Width Modulation) converter due to some troubles of the switching devices. In this case, the converter causes the unbalanced input AC currents including harmonics and the ripple of DC-link voltage. This paper proposes the phase detection method of open-switch fault and the fault-tolerant control algorithm to minimize the unbalance of the input AC current and the ripple voltage of the DC-link in 3-phase AC-DC PWM converter. In particular, open-switch fault case of one switch among six switches of PWM converter is analyzed. The usefulness of this paper is verified through the computer simulation and experimentation, respectively.