FAULT DIAGNOSIS METHOD FOR FREE-WHEELING DIODE OF DUAL-SWITCH POWER CONVERTER OF SWITCHED RELUCTANCE MOTOR

摘要

A fault diagnosis method for a free-wheeling diode of a dual-switch power converter of a switched reluctance motor. Two current sensors are provided on an each-phase dual-master-switch power converter, one current sensor (LEM1) is used for detecting a total current (iT) of lower master switch diodes (S4-S6) of a direct current bus, and the other current sensor (LEM2) is used for detecting a total current (iD) fed back by lower free-wheeling diodes (VD4-VD6) of the direct current bus. On or OFF of upper and lower master switch diodes (S1-S6) are controlled to determine a short-circuit fault occurring in upper free-wheeling diodes (VD1-VD3), a short-circuit fault occurring in the lower free-wheeling diodes (VD4-VD6), a short-circuit fault occurring in the upper and the lower free-wheeling diodes, an open-circuit fault occurring in the upper free-wheeling diodes, an open-circuit fault occurring in the lower free-wheeling diodes, or an open-circuit fault occurring in the upper and the lower free-wheeling diodes. By means of the method, accurate fault detection, distinguishing of a fault type, and positioning of a fault phase of a free-wheeling diode are achieved, and implementation of fault-tolerant control of a free-wheeling diode is facilitated.