Field-Experience Based Root-Cause Analysis of Power-Converter Failure in Wind Turbines

Abstract

The frequent power-converter failure experienced in wind turbines has a strong economic impact through both the related turbine unavailability and the maintenance cost. Up to now, the prevailing mechanisms and causes underlying the converter failure in wind turbines are mostly unknown. Their identification is, however, a prerequisite for the development of effective solutions. This paper describes a multi-track empirical approach to failure analysis including systematic field-data evaluation, exploration of the real converter operating environment, and post-operational laboratory investigation of converter hardware. The analysis is carried out for two widelyused multi-MW wind turbines with low-voltage, IGBT-based converters (topology 1: doubly-fed induction generator with partially rated converter, topology 2: induction generator with fully-rated converter). The findings suggest that the principle failure mechanisms of power electronics found in other applications, namely solder degradation and bond-wire damage, play a minor role in the investigated types of wind turbines. Instead, the analysis reveals indications of insufficient protection of the converter hardware against the environment (salt, condensation, and insects) as well as indications of electrical overstress.Index Terms-wind turbine, converter, reliability, failure, root-cause analysis, power electronics I. INTRODUCTIONOWER converters are a frequent source of failure in modern wind turbines. In a reliability field-study on pitchcontrolled, variable-speed onshore wind turbines with rated capacity ≥850 kW, in which more than 31000 downtime events were evaluated, the frequency converters were found to Manuscript

Reducing cost uncertainty in the drivetrain design decision with a focus on the operational phase

“…Failure rate Weibull distribution/Triangulation (Fischer and Wenske, 2015;Fischer et al, 2015;Ozturk et al, 2018;Shafiee and Dinmohammadi, 2014;Ribrant Johan, 2006;Dinmohammadi and Shaffiee, 2013;Arabian-Hoseynabadi et al, 2010;Carroll et al, 2017;Berger, 2016;Reder et al, 2016;Carroll et al, 2016 Referring to Formula (2) the estimation of O&M effort (OME) is constituted by material, labour, and crane expenses (compare 170 Table 1). Minor repair is repair which leads to material cost up to 1,000 €.…”

“…;Dinwoodie* and D. McMillan, 2012;Pinar Pérez et al, 2013;Wilson and McMillan, 2014;Carroll et al, 2014a;Tavner and Spinato, 2008) DowntimeNormal distribution(Fischer and Wenske, 2015;Samet Ozturk, Vasilis Fthenakis and Stefan Faulstich;Ribrant Johan, 2006;Carroll et al, 2017;Reder et al, 2016;Dinwoodie* and D. McMillan, 2012;Pinar Pérez et al, 2013;Carroll et al, 2016) Failure severity Uniformly distributed random number(Carroll et al, 2015b) Duration of repair Triangulation/constant(Carroll et al, 2016;Carroll et al, 2017) Overview of model structure…”

Modeling of Doubly Fed Induction Generator for Vertical Axis Wind Turbine

“…Fig. 1 presents the optimal control strategy using the grid load, approaching the charging control by rotor voltages of DFIM at operating points as well as controlling converters by the grid loading [9,12].…”

A fuzzy TOPSIS and Rough Set based approach for mechanism analysis of product infant failure

“…Motamedi et al (2014) proposed a knowledge-assisted BIM (Building Information Modeling)-based visual analytics approach for failure root-cause detection in FM (facilities management), in which various sources of building knowledge such as fault trees and relationships between components are formally represented. Fischer et al (2015) described a multi-track empirical approach to failure analysis including systematic field-data evaluation, exploration of the real converter operating environment, and post-operational laboratory investigation of converter hardware.…”