Condition monitoring

About: Condition monitoring is a research topic. Over the lifetime, 13911 publications have been published within this topic receiving 201649 citations.

Review of Physicochemical-Based Diagnostic Techniques for Assessing Insulation Condition in Aged Transformers

Abstract: A power transformer outage has a dramatic financial consequence not only for electric power systems utilities but also for interconnected customers. The service reliability of this important asset largely depends upon the condition of the oil-paper insulation. Therefore, by keeping the qualities of oil-paper insulation system in pristine condition, the maintenance planners can reduce the decline rate of internal faults. Accurate diagnostic methods for analyzing the condition of transformers are therefore essential. Currently, there are various electrical and physicochemical diagnostic techniques available for insulation condition monitoring of power transformers. This paper is aimed at the description, analysis and interpretation of modern physicochemical diagnostics techniques for assessing insulation condition in aged transformers. Since fields and laboratory experiences have shown that transformer oil contains about 70% of diagnostic information, the physicochemical analyses of oil samples can therefore be extremely useful in monitoring the condition of power transformers.

Condition monitoring of electrical drives

Abstract: This paper outlines an approach to the monitoring of electrical drives by the method of axial flux sensing. It is shown that it is possible to detect a variety of faults using a single noninvasive sensor. A prototype system design incorporating several novel features is also discussed, and experimental results presented.

A Voltage-Based Approach Without Extra Hardware for Open-Circuit Fault Diagnosis in Closed-Loop PWM AC Regenerative Drives

Abstract: The widespread use of electric drives has led to an increasing interest in their condition monitoring and fault diagnostics. With respect to power-switch open-circuit fault diagnosis, the majority of the proposed voltage-based approaches require additional hardware, increasing the system cost. As a result, industry acceptance may be low. This paper proposes a new voltage-based approach-without additional sensors-for open-circuit fault diagnosis in closed-loop controlled pulsewidth-modulation (PWM) ac voltage source converters, by using the information contained in the reference voltages available from the control system. The robustness against false alarms of the proposed technique is improved by employing a voltage observer, in order to estimate the actual converter voltages. It has been proven that the algorithm is insensitive to parameter errors; thus, its effectiveness is not compromised. In order to assess the applicability of the diagnostic technique, it is integrated into the control system of a permanent-magnet-synchronous-machine drive, with regenerative capabilities, together with three of the most widely used PWM control strategies: hysteresis current control, direct torque control, and space vector modulation. The technique performance is analyzed in detail by means of several experimental results.