Reliability evaluation of insulation subjected to harmonic voltages within the limits set by international standards

This paper aims at providing reliability evaluation tools for the insulation of power system components subjected to low-order harmonic voltages that match the voltage distortion limits set by International Standards. This goal does make sense from the technical-scientific viewpoint. Indeed, as shown in the first part of the paper, even in a distorted regime that matches such limits the peak and shape factors of the distorted voltage may be high enough to accelerate insulation aging, and reduce rated life and reliability of components. Thus, in the second part of the paper the so-called "harmonic voltage safety indices" are found for assessing whether power system components are at risk under a given distorted voltage waveform, even if it complies with the voltage distortion limits set by International Standards. These reliability evaluation tools are applied to LV/MV capacitors and cables, but can be extended to other insulations, e.g. those of induction motors and transformers.

[1]  Elio Chiodo,et al.  Mathematical and Physical Properties of Reliability Models in View of their Application to Modern Power System Components , 2011 .

[2]  S. M. Rowland,et al.  The Relationship Between Insulation Ageing and Power Network Performance , 2007, 2007 IEEE International Conference on Solid Dielectrics.

[3]  Davide Fabiani,et al.  The effect of nonsinusoidal voltage on intrinsic aging of cable and capacitor insulating materials , 1999 .

[4]  G. Nahler,et al.  : Accelerated testing , 1999 .

[5]  Gian Carlo Montanari,et al.  Progress in electrothermal life modeling of electrical insulation during the last decades , 2002 .

[6]  J. C. Das,et al.  Power System Harmonics , 2015 .

[7]  S. Bahadoorsingh,et al.  A Framework Linking Knowledge of Insulation Aging to Asset Management - [Feature Article] , 2008, IEEE Electrical Insulation Magazine.

[8]  Daniele Gallo,et al.  On the effects on MV/LV component expected life of slow voltage variations and harmonic distortion , 2002, 10th International Conference on Harmonics and Quality of Power. Proceedings (Cat. No.02EX630).

[9]  Davide Fabiani,et al.  Models for degradation of self-healing capacitors operating under voltage distortion and temperature , 2000, Proceedings of the 6th International Conference on Properties and Applications of Dielectric Materials (Cat. No.00CH36347).

[10]  R. Brook,et al.  Cumulative Damage in Fatigue: A Step towards Its Understanding , 1969 .

[11]  Daniele Gallo,et al.  Predicting voltage stress effects on MV/LV components , 2003, 2003 IEEE Bologna Power Tech Conference Proceedings,.

[12]  G. Mazzanti,et al.  The effects of voltage waveform factors on cable life estimation using measured distorted voltages , 2006, 2006 IEEE Power Engineering Society General Meeting.

[13]  F. Mauseth,et al.  Diagnostic testing of thermally aged medium voltage XLPE cable joints , 2012, 2012 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[14]  Davide Fabiani,et al.  Power electronics and electrical insulation systems - part 2: life modeling for insulation design , 2010, IEEE Electrical Insulation Magazine.

[15]  F. Mauseth,et al.  Water tree growth of wet XLPE insulation stressed with DC and high frequency AC , 2012, 2012 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[16]  Nikos D. Hatziargyriou,et al.  Technical requirements for the connection of dispersed generation to the grid , 2001, 2001 Power Engineering Society Summer Meeting. Conference Proceedings (Cat. No.01CH37262).

[17]  G. Mazzanti.  Distortion limits in international standards vs. reliability of power components: Always on the safe side as to low-order voltage harmonics? , 2012, 2012 IEEE Power and Energy Society General Meeting.