Fault Tolerant Three-Phase AC Motor Drive Topologies: A Comparison of Features, Cost, and Limitations

TLDR

The paper reviews two‑phase and unipolar control methods used in fault‑tolerant inverters. The study compares fault‑tolerant three‑phase AC motor drive topologies that maintain output capacity during inverter faults such as switch or phase‑leg short‑circuit and single‑phase open‑circuit. The authors identify the dq‑space voltage and current limits for each topology under fault, normalize the fault power capacity to a standard inverter, and use a silicon overrating cost factor to compare switching‑device costs.

Abstract

This paper compares the many fault tolerant three-phase ac motor drive topologies that have been proposed to provide output capacity for the inverter faults of switch short or open-circuits, phase-leg short-circuits, and single-phase open-circuits. Also included is a review of the respective control methods for fault tolerant inverters including two-phase and unipolar control methods. The output voltage and current space in terms of dq components is identified for each topology and fault. These quantities are then used to normalize the power capacity of each system during a fault to a standard inverter during normal operation. A silicon overrating cost factor is adopted as a metric to compare the relative switching device costs of the topologies compared to a standard three-phase inverter.