A Fault Verification Method Based on the Substitution Theorem and Voltage-Current Phase Relationship

Abstract

This paper presents a new fault verification method for diagnosis of parametric faults in linear analog circuits. Although there has been much research on fault verification methods there are still some open problems, such as low testability and extensive computational procedures in the case of multiple faults. The proposed method is based on the substitution theorem. It deals with the branch currents and voltages as opposed to the standard branch fault verification method, which only considers the branch current deviations. In this way, both the magnitude and phase angle of the faulty currents are taken into consideration, allowing us to check the physical meaning of the faulty currents. The fault detection procedure is based on the frequency domain measurements and the use of the sinusoidal excitation. The presented approach enhances the diagnosability, reduces on-line computations and decreases the number of required test nodes by one. The feasibility of the method is demonstrated through measurement experiments.