Abstract
This paper discusses a new system using a microcomputer for diagnosing a large-scale analog control system in an electric power plant or an industrial plant. When a trouble occurs in the control system, this diagnosis system can instruct the operators correct actions for the load operation and can indicate fault locations for the repair work.
The features of the diagnosis system are the following: (1) to detect failures in the control devices (such as sensors, actuators and operational modules) by using signal processing methods such as reference checks, static correlation checks, and reasonableness checks; and (2) to locate faulty control loops for operators to act against a plant shutdown by using a decision table method.
The diagnosis system has been applied to the automatic boiler control system of an actual thermal power plant. In this paper, we describe the results of diagnosis of an artificial trouble, and the results of a statistical analysis for effects of the signal processing.
