A Reliability Evaluation Model for the Power Devices Used in Power Converter Systems Considering the Effect of the Different Time Scales of the Wind Speed Profile

Abstract

This paper presents a reliability assessment model for the power semiconductors used in wind turbine power converters. In this study, the thermal loadings at different timescales of wind speed are considered. First, in order to address the influence of long-term thermal cycling caused by variations in wind speed, the power converter operation state is partitioned into different phases in terms of average wind speed and wind turbulence. Therefore, the contributions can be considered separately. Then, in regards to the reliability assessment caused by short-term thermal cycling, the wind profile is converted to a wind speed distribution, and the contribution of different wind speeds to the final failure rate is accumulated. Finally, the reliability of an actual power converter semiconductor for a 2.5 MW wind turbine is assessed, and the failure rates induced by different timescale thermal behavior patterns are compared. The effects of various parameters such as cut-in, rated, cut-out wind speed on the failure rate of power devices are also analyzed based on the proposed model.

Enhance Reliability of Semiconductor Devices in Power Converters

“…Electronics 2020, 9, x FOR PEER REVIEW 25 of 37 different thermal swings is found by using simple linear damage models such as the Palmgren-Miner model [135]. As analyzed in [136,137], correct transforming the mission profile of the converter in the real application as wind power into the corresponding loading profile of the power devices is a challenging task. According to the main causes of loading in a power converter of wind turbine applications, the thermal behavior of power electronic components can be generally classified into three times constant: long term, medium term, and short term.…”