EPE Association: EPE 2020 - DS1b-1: Reliability & Life-Time-1

EPE 2020 - DS1b-1: Reliability & Life-Time-1
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 01: Devices, Packaging and System Integration > EPE 2020 - DS1b-1: Reliability & Life-Time-1

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   Component-level Reliability Assessment of a Direct-drive PMSG Wind Power Converter Considering Long-term and short-term thermal cycles
By Shuaichen YE [View]
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Abstract: The lifespan of a wind power system is highly influenced by the reliable operation of its power converter. This paper investigates the failure rate and annual consumed damage for a 2 MW direct-drive permanent magnet synchronous generator (PMSG) based power converter in a wind power generation system. The reliability assessment mainly focuses on the component level, namely, diodes and IGBTs, in the machine-side converter (MSC). Annual damages and power cycles for semiconductors are calculated separately under long-term thermal cycles (several minutes to several hours) and short-term thermal cycles (dozens to hundreds of milli-second). A comparison result between different thermal cycles are given and discussed in detail. To ensure an effective lifetime evaluation of the entire converter system, a Monte Carlo method is used to generate the lifetime distributions and entire unreliability functions for power semiconductors. Final B10 and B1 lifetimes can be easily observed from the cumulative distribution functions (CDFs).

   Influence of Wire-Bonding Layout on Reliability in IGBT Module
By Lubin HAN [View]
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Abstract: The wire-bonding layouts influence the profiles of current density, ohmic loss and junction temperature. The temperature profile across IGBT chip is different when the wire-bonding layouts are different. Reasonable wire-bonding layout could reduce the maximum junction temperature (Tjmax) of the chip and slow down the aging process of the solder and bonding wires. The uniform wire-bonding layout is proposed in this paper to improve the packaging reliability of the power module. To analyze the influence of wire-bonding layouts on reliability, the centralized wire-bonding layout and uniform wire-bonding layout of bonding wires are compared. The results of the electro-thermal simulation show that using uniform wire-bonding layout reduces the Tjmax of the chip by 1~3 °C. What's more, as distance between wire-bonding point and chip center increases, there is a minimum value of Tjmax in the uniform wire-bonding layout. The analytical model is deduced to study the phenomenon. To verify the simulation and theoretical analysis results, the IGBT modules with centralized wire-bonding layout and uniform wire-bonding layout of bonding wire are tested by power cycling tests (PCT). The experimental results show that the Tjmax of the module with uniform wire-bonding layout of bonding wire is 3.3 °C lower than that of the module with centralized wire-bonding layout. Correspondingly, with the help of LESIT lifetime model, the calculated lifetime of the IGBT module with uniform wire-bonding layout increases by 1/3, compared with centralized wire-bonding layout.

   Maintenance Scheduling in Power Electronic Converters Considering Wear-out Failures
By Saeed PEYGHAMI [View]
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Abstract: Power electronic converters are one of failure sources in energy systems, and hence drivers of downtime costs in power systems. Different approaches can be employed for converter reliability enhancement including design/control for reliability methods, condition monitoring and fault diagnosis, and maintenance strategies. This paper proposes optimal preventive maintenance strategies based on wear-out failure model of converter components. The proposed approaches employ two different performance measures at converter-level and system-level. The converter-level measures take into account planned and unplanned maintenance times or costs in a single unit or small-scale system. Moreover, the system-level measure considers not only maintenance times, but also energy losses and additional maintenance costs induced by aging of the converter components. The outcome is optimal replacement time of converter and its components, which depends on the employed performance measure. Optimal replacement scheduling is of importance for risk management and decision-making during planning of modern power electronic based power systems. The applicability of the proposed approaches is illustrated by numerical analysis in a photovoltaic system.

   Mechanistic Power Module Degradation Modelling Concept with Feedback
By Martin FOGSGAARD [View]
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Abstract: A platform will be presented based on physics-of-failure-based models. The platform gives an overview of the couplings between simulation, health monitoring and online lifetime prediction of a power module. The platform is modular and is not tied to any specific software product to make it as generally applicable as possible.

   System-Level Reliability Analysis of a Repairable Power Electronic-Based Power System Considering Non-Constant Failure Rates
By Amirali DAVOODI [View]
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Abstract: Conventionally, for reliability studies in power systems, a constant failure rate is assumed for generation units. If these units consist of power electronic converters, due to the aging of power components, this assumption might not be valid and will lead to the unrealistic prediction of reliability. On the other hand, at the system-level, commonly-used reliability calculation tools, such as Monte Carlo Simulation (MCS) and Continuous Markov Process (CMP), are either time-consuming or unable to be applied to the systems with non-constant failure rates. Therefore, in this paper, a methodology is proposed to calculate system-level reliability for a Power-Electronic-based Power System (PEPS), consisting of several converters with non-constant failure rates. By doing so, not only is the effect of mission profiles integrated into the system-level reliability model, but also the wear-out failures and corrective maintenance are considered. Finally, for a case study PEPS, the system-level indices are calculated using the proposed method. It is shown that assuming constant failure rates for PEPS units is inaccurate and misleading. Moreover, the impact of various factors, e.g., mission profile, repair rate, topology, and rating of converters, on the system-level reliability is investigated and analyzed.

EPE 2020 - DS1b-1: Reliability & Life-Time-1
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 01: Devices, Packaging and System Integration > EPE 2020 - DS1b-1: Reliability & Life-Time-1
	[return to parent folder]

	Component-level Reliability Assessment of a Direct-drive PMSG Wind Power Converter Considering Long-term and short-term thermal cycles By Shuaichen YE	[View] [Download]
Abstract: The lifespan of a wind power system is highly influenced by the reliable operation of its power converter. This paper investigates the failure rate and annual consumed damage for a 2 MW direct-drive permanent magnet synchronous generator (PMSG) based power converter in a wind power generation system. The reliability assessment mainly focuses on the component level, namely, diodes and IGBTs, in the machine-side converter (MSC). Annual damages and power cycles for semiconductors are calculated separately under long-term thermal cycles (several minutes to several hours) and short-term thermal cycles (dozens to hundreds of milli-second). A comparison result between different thermal cycles are given and discussed in detail. To ensure an effective lifetime evaluation of the entire converter system, a Monte Carlo method is used to generate the lifetime distributions and entire unreliability functions for power semiconductors. Final B10 and B1 lifetimes can be easily observed from the cumulative distribution functions (CDFs).

	Influence of Wire-Bonding Layout on Reliability in IGBT Module By Lubin HAN	[View] [Download]
Abstract: The wire-bonding layouts influence the profiles of current density, ohmic loss and junction temperature. The temperature profile across IGBT chip is different when the wire-bonding layouts are different. Reasonable wire-bonding layout could reduce the maximum junction temperature (Tjmax) of the chip and slow down the aging process of the solder and bonding wires. The uniform wire-bonding layout is proposed in this paper to improve the packaging reliability of the power module. To analyze the influence of wire-bonding layouts on reliability, the centralized wire-bonding layout and uniform wire-bonding layout of bonding wires are compared. The results of the electro-thermal simulation show that using uniform wire-bonding layout reduces the Tjmax of the chip by 1~3 °C. What's more, as distance between wire-bonding point and chip center increases, there is a minimum value of Tjmax in the uniform wire-bonding layout. The analytical model is deduced to study the phenomenon. To verify the simulation and theoretical analysis results, the IGBT modules with centralized wire-bonding layout and uniform wire-bonding layout of bonding wire are tested by power cycling tests (PCT). The experimental results show that the Tjmax of the module with uniform wire-bonding layout of bonding wire is 3.3 °C lower than that of the module with centralized wire-bonding layout. Correspondingly, with the help of LESIT lifetime model, the calculated lifetime of the IGBT module with uniform wire-bonding layout increases by 1/3, compared with centralized wire-bonding layout.

	Maintenance Scheduling in Power Electronic Converters Considering Wear-out Failures By Saeed PEYGHAMI	[View] [Download]
Abstract: Power electronic converters are one of failure sources in energy systems, and hence drivers of downtime costs in power systems. Different approaches can be employed for converter reliability enhancement including design/control for reliability methods, condition monitoring and fault diagnosis, and maintenance strategies. This paper proposes optimal preventive maintenance strategies based on wear-out failure model of converter components. The proposed approaches employ two different performance measures at converter-level and system-level. The converter-level measures take into account planned and unplanned maintenance times or costs in a single unit or small-scale system. Moreover, the system-level measure considers not only maintenance times, but also energy losses and additional maintenance costs induced by aging of the converter components. The outcome is optimal replacement time of converter and its components, which depends on the employed performance measure. Optimal replacement scheduling is of importance for risk management and decision-making during planning of modern power electronic based power systems. The applicability of the proposed approaches is illustrated by numerical analysis in a photovoltaic system.

	Mechanistic Power Module Degradation Modelling Concept with Feedback By Martin FOGSGAARD	[View] [Download]
Abstract: A platform will be presented based on physics-of-failure-based models. The platform gives an overview of the couplings between simulation, health monitoring and online lifetime prediction of a power module. The platform is modular and is not tied to any specific software product to make it as generally applicable as possible.

	System-Level Reliability Analysis of a Repairable Power Electronic-Based Power System Considering Non-Constant Failure Rates By Amirali DAVOODI	[View] [Download]
Abstract: Conventionally, for reliability studies in power systems, a constant failure rate is assumed for generation units. If these units consist of power electronic converters, due to the aging of power components, this assumption might not be valid and will lead to the unrealistic prediction of reliability. On the other hand, at the system-level, commonly-used reliability calculation tools, such as Monte Carlo Simulation (MCS) and Continuous Markov Process (CMP), are either time-consuming or unable to be applied to the systems with non-constant failure rates. Therefore, in this paper, a methodology is proposed to calculate system-level reliability for a Power-Electronic-based Power System (PEPS), consisting of several converters with non-constant failure rates. By doing so, not only is the effect of mission profiles integrated into the system-level reliability model, but also the wear-out failures and corrective maintenance are considered. Finally, for a case study PEPS, the system-level indices are calculated using the proposed method. It is shown that assuming constant failure rates for PEPS units is inaccurate and misleading. Moreover, the impact of various factors, e.g., mission profile, repair rate, topology, and rating of converters, on the system-level reliability is investigated and analyzed.