Time delay as a diagnostic technique for power drives

A novel technique to evaluate changes over time of trigger circuit parameters, especially the power transistors of standard power electronic converters is proposed. This technique takes advantage of existing instrumentation and provides a key novel feature to assess the aging status of power electronic circuits and electric machines as a result of transistor degradation. We propose the use of a low-cost digital circuit, capable of time delay tracking. A simplified platform for the implementation of the time delay tracking and its experimental evaluation are presented. Experimental data is included and the viability of the diagnostic technique as a practical real-time device health-state indicator assessed.