Exploring the Causes of Power-Converter Failure in Wind Turbines based on Comprehensive Field-Data and Damage Analysis

Katharina Fischer,Jan Wenske,Arne Bartschat,Max-Hermann Poech,Christian Broer,Bernd Tegtmeier,Karoline Pelka,Axel Mertens,Sebastian Puls

doi:10.3390/en12040593

Abstract

Power converters are among the most frequently failing components of wind turbines. Despite their massive economic impact, the actual causes and mechanisms underlying these failures have remained in the dark for many years. In view of this situation, a large consortium of three research institutes and 16 companies, including wind-turbine and component manufacturers, operators and maintenance-service providers has joined forces to identify the main causes and driving factors of the power-converter failures in wind turbines to create a basis for effective remedial measures. The present paper summarizes and discusses the results of this research initiative, which have been achieved through the evaluation of converter-specific failure and operating data of a large and diverse worldwide wind-turbine fleet, field measurements as well as post-mortem investigation of returned converter components. A key conclusion of the work is that the thermal-cycling induced fatigue of bond-chip contacts and die-attach solder, which is a known issue in other fields of power-electronics applications and which has been widely assumed to be the principle damage mechanisms also in wind turbines, is no relevant contributor to the observed converter failures in this application. Instead, the results indicate that environmental factors such as humidity and contamination but also design and quality issues as well as human errors play an important part in the incidence of these failures.

Highlights

Power-electronic converters are key components in variable-speed wind turbines (WTs)
The field-data compiled and evaluated in the Innovation Cluster covers WTs with different generator-converter concepts, of a multitude of manufacturers and at sites with a variety of wind regimes. The latter has not been taken into consideration in our previous presentations and comparisons of converter failure rates
WTsthe in excited synchronous generator (EESG)‐based our dataset)WTs exhibit low converter rates mainly tomainly the fact that in our dataset) exhibit particularlyfailure low converter failuredue rates due to they the might be operating at full load

Summary

Introduction

Power-electronic converters are key components in variable-speed wind turbines (WTs). They are among the most frequently failing components of WTs. At the same time, they are among the most frequently failing components of WTs This has been shown by numerous system-level studies evaluating the reliability of wind turbines in different parts of the world. According to the RELIAWIND study based on data from 373 WTs with a total of 1115 WT operating years from 2004–2010, the power converter ranks second with regard to both the failure rate and the resulting downtime [1,2]. A study evaluating >5800 failures in wind farms in China during. Recent system-level reliability data collected within the SPARTA initiative during 2015–2016, which 2010–2012 identified the frequency converter as the by far most frequently failing component [3].

Results

Discussion

Conclusion