ROTARY MACHINE QUALITY DIAGNOSTIC SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a system capable of diagnosing the presence or absence of abnormality occurring in an operating rotary machine without stopping the rotary machine while a load is connected.SOLUTION: A rotary machine quality diagnostic system diagnoses quality of a rotary machine during operation by: measuring current flowing to each phase of a normal rotary machine that operates by being connected to a load, with respect to each of differently-sized loads; obtaining a feature quantity of each load; obtaining a basic line of a region where the feature quantities are distributed; defining a probability density function of an index to be used for determining the quality of the rotary machine, as a function of distance from the line; deciding a value of a standard deviation in the probability density function so that the index takes a specific value when the distance between the feature quantity and the line becomes a certain value; storing this value in a computer; obtaining the distance between a feature quantity obtained in diagnosing the rotary machine and the line when the feature quantity is obtained; using a value of the distance and the preliminarily-obtained value of the standard deviation to calculate a failure probability showing a determination index; and setting a threshold to the value.