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In this paper a leading indicators of failure has been developed to monitor the progression of fretting corrosion in electrical connectors and prognosticate remaining useful life. Connectors subjected to harsh environments may experience vibration resulting in fretting corrosion and degradation in contact resistance over time. Tin coated, rectangul...
Citations
... The final model indicated the direct correlation between the connector reliability function with the cumulative distribution function of the contact resistance distribution. Lall et al. applied the Kalman filter in the form of state space model to predict the remaining useful life of electrical connectors subjected to mechanical loads [18]. Zhao et al. predicted the remaining storage life of electromagnetic relays by combining leave-one-out cross validation with particle filtering method where the contact degradation due to organic and inorganic pollutants was accounted for [19]. ...
... RUL estimation of micro switches based on Bayesian updating and expectation maximization combined with strong tracking filtering was presented in [25], the failure threshold being based on the contact voltage drop between contacts once closed, which is directly related to the contact resistance. In [26], failure indicators based on the change of the electrical resistance of small size socket electrical connectors are applied to predict the RUL of such components based on random vibration tests carried out to produce fretting corrosion degradation. Resistance was measured by applying the resistance spectroscopy technique jointly with phase sensitive detection, and a Kalman filter was applied for estimating the health status of the socket connector. ...
Connections are critical elements in power systems, exhibiting higher failure probability. Power connectors are considered secondary simple devices in power systems despite their key role, since a failure in one such element can lead to major issues. Thus, it is of vital interest to develop predictive maintenance approaches to minimize these issues. This paper proposes an on-line method to determine the remaining useful life (RUL) of power connectors. It is based on a simple and accurate model of the degradation with time of the electrical resistance of the connector, which only has two parameters, whose values are identified from on-line acquired data (voltage drop across the connector, electric current and temperature). The accuracy of the model presented in this paper is compared with the widely applied autoregressive integrated moving average model (ARIMA), showing enhanced performance. Next, a criterion to determine the RUL is proposed, which is based on the inflection point of the expression describing the electrical resistance degradation. This strategy allows determination of when the connector must be replaced, thus easing predictive maintenance tasks. Experimental results from seven connectors show the potential and viability of the suggested method, which can be applied to many other devices.
... In [15], the RUL of microswitches was estimated by applying different methods, including Bayesian updating, expectation maximization, and strong tracking filtering [15]. In [16], the RUL of socket connectors was determined by analyzing the change in the resistance. ...
The ageing process of medium voltage power connectors can lead to important power system faults. An on-line prediction of the remaining useful life (RUL) is a convenient strategy to prevent such failures, thus easing the application of predictive maintenance plans. The electrical resistance of the connector is the most widely used health indicator for condition monitoring and RUL prediction, even though its measurement is a challenging task because of its low value, which typically falls in the range of a few micro-ohms. At the present time, the RUL of power connectors is not estimated, since their electrical parameters are not monitored because medium voltage connectors are considered cheap and secondary devices in power systems, despite they play a critical role, so their failure can lead to important power flow interruptions with the consequent safety risks and economic losses. Therefore, there is an imperious need to develop on-line RUL prediction strategies. This paper develops an on-line method to solve this issue, by predicting the RUL of medium voltage connectors based on the degradation trajectory of the electrical resistance, which is characterized by analyzing the electrical resistance time series data by means of the autoregressive integrated moving average (ARIMA) method. The approach proposed in this paper allows applying predictive maintenance plans, since the RUL enables determining when the power connector must be replaced by a new one. Experimental results obtained from several connectors illustrate the feasibility and accuracy of the proposed approach for an on-line RUL prediction of power connectors.
... Application of the RS method is described in extensive detail in Refs.3456. The RS method for prognostics has been applied to a variety of interconnect alloys (3456 : SAC305, SnPb, and HiPb), interconnect geometries (copper columns3456, HiPb columns/microcoils [16]), and Molex computer connectors [17]. In this paper, the system being studied is SAC305 ball grid array interconnects. ...
This paper compares three prognostic algorithms applied to the same data recorded during the failure of a solder joint in ball grid array component attached to a printed circuit board. The objective is to expand on the relative strengths and weaknesses of each proposed algorithm. Emphasis will be placed on highlighting differences in underlying assumptions required for each algorithm, details of remaining useful life calculations, and methods of uncertainty quantification. Metrics tailored specifically for prognostic health monitoring (PHM) are presented to characterize the performance of predictions. The relative merits of PHM algorithms based on a Kalman filter, extended Kalman filter, and a particle filter all demonstrated on the same data set will be discussed. The paper concludes by discussing which algorithm performs best given the information available about the system being monitored.
Many connections exist in complex electronic equipment, which leads to a long duration of intermittent fault test and difficulty in achieving comprehensive coverage of intermittent fault. The intermittent fault mechanism and the multichannel intermittent fault parameter parallel capture method are investigated. A smaller module covers multiple intermittent connection faults in electronics and prevents missed detections. Based on the test results, a reliability assessment of the connection link with intermittent faults is needed in the next step. The correlation between the intermittent fault parameters and the reliability of connection link is analyzed, and the intermittent fault parameters are used to evaluate the connection link reliability. An aviation electrical connector and solder joint are used for testing. The results show that increases in the intermittent fault parameters are consistent with the trend of reliability degradation, which indicates that the proposed method can be applied to intermittent fault testing and reliability assessment for the connection link of electronic equipment.
The reliability of electrical connectors has a critical impact on electrical systems. Traditionally, this has been characterized by the failure-rate prediction value according to MIL-HDBK-217 in engineering practice. Owing to the limitations and misleading results provided by this approach, a new remaining useful life (RUL) prediction method is presented. This method is aimed at the mechanism of increasing oxide film thickness induced by vibration, which leads to an increase in contact resistance. Moreover, the prediction method is based on failure mechanisms and particle filters, which realizes the combination of a physical model and data-driven method. The particle filters can abundantly employ degradation data and avoid ignoring the failure mechanism. Accelerated degradation testing (ADT) is proposed for effectively assessing the proposed prediction method, in which the random vibration is selected as the accelerated stress. Moreover, the differences in manufacturing processes are considered in the testing. The RULs of circular electrical connectors in two manufacturing processes are obtained under high vibration stress through ADT and data gained from tests. The prediction results are compared with other methods to verify the accuracy and effectiveness of the proposed prediction method.
Intermittent faults in electrical/electronic interconnections are recognised as one of the major sources of No Fault Found (NFF) events. These can be caused due to surface corrosion (e.g. oxidation of pins or fretting wear), bent pins, debris within the female connector, or incorrect installation during initial manufacture and assembly. Unless such issues are narrowed down to a specific root cause, any corrective actions or troubleshooting will be difficult to carry out, and hence its resolution may not make its way into future designs of the system. This leads to further susceptibility to NFF. Intermittent behaviour is often a clear sign of a partially damaged connector, or a connector undergoing a particular degradation mechanism, with the level of intermittency being further aggravated through process variation of harsh environments and parametric faults. In order to further our understanding of the relationship between degradation, operating conditions, intermittent behaviour within the subject, an experimental investigations have been carried out.This paper is a work in progress paper that illustrates a test regime that has been used to stimulate intermittence in electronic connectors whilst subjected to vibration, using both a traditional oscilloscope and bespoke intermittent fault detection equipment, in order to capture an intermittent signature. The results of these experiments provide an insight into the limitations of test equipment and requirements for future intermittent fault detection techniques.
