Research Of Fault Diagnosis On Converter System In Electric Haul Truck

Electric haul truck as ultra-class haulers among mining equipment plays a vital role in the history of industrial development like mine production, water conservancy and hydropower and other industries related. But while severe operation surroundings lead to high failure rate and increasing maintenance cost, making production efficiency declined and project progress slowed. And these failures which locates in electrical section is noticeable and receives attention and research widely.Based on the bond graph theory and its application in modeling hybrid system and failure diagnosis, this paper builds the model of the power converter, the electrical part of electric haul truck and then studies its fault analog and diagnosis, and open circuit at switch in particular. Firstly, in order to keep time-invariant preferred causality at bond graph model, it has been proposed to approximate the diode characteristic in rectifier via a piecewise function that accounts for the ON/OFF-resistance. Further, bond graph model of conversion system based on such representation and the other is then presented from which analytical redundancy relations, as an effective failure diagnosis approach, is illustrated by modeling and simulation of some fault scenarios to detect and isolate these faults through evaluating and combing one or more independent residuals in fault signature matrix. And the simulation verification shows that all the conclusions involved are remarkably right. Additionally, and innovatively, by the means of failure information and diagnosis result, two redundant constructions with signal pre-processing unit about rectification and invert respectively are given to insure its performance unchanged under potential trouble mentioned in this paper.The presented approach is not confined to power electronic systems but can also be used for hybrid systems in other domains. In further work, the RL-load may be replaced by a bond graph model of an alternating current motor to study the effect of switch failures on the dynamic behavior of the motor.