scholarly journals Intelligent long-term performance analysis in power electronics systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Peyghami ◽  
Tomislav Dragicevic ◽  
Frede Blaabjerg
Keyword(s):  
Performance Indicator ◽  
Thermal Characteristics ◽  
Operating Conditions ◽  
System Level ◽  
Power Electronic ◽  
Reliability Modeling ◽  
Artificial Neural Network Ann ◽  
Long Term Performance ◽  
Term Performance

AbstractThis paper proposes a long-term performance indicator for power electronic converters based on their reliability. The converter reliability is represented by the proposed constant lifetime curves, which have been developed using Artificial Neural Network (ANN) under different operating conditions. Unlike the state-of-the-art theoretical reliability modeling approaches, which employ detailed electro-thermal characteristics and lifetime models of converter components, the proposed method provides a nonparametric surrogate model of the converter based on limited non-linear data from theoretical reliability analysis. The proposed approach can quickly predict the converter lifetime under given operating conditions without a further need for extended, time-consuming electro-thermal analysis. Moreover, the proposed lifetime curves can present the long-term performance of converters facilitating optimal system-level design for reliability, reliable operation and maintenance planning in power electronic systems. Numerical case studies evaluate the effectiveness of the proposed reliability modeling approach.

scholarly journals Intelligent Long-Term Performance Analysis in Power Electronics Systems

2020 ◽  
Author(s):  
Saeed Peyghami ◽  
Tomislav Dragicevic ◽  
Frede Blaabjerg
Keyword(s):  
Performance Indicator ◽  
Thermal Characteristics ◽  
Operating Conditions ◽  
System Level ◽  
Power Electronic ◽  
Reliability Modeling ◽  
Artificial Neural Network Ann ◽  
Long Term Performance ◽  
Term Performance

Abstract This paper proposes a long-term performance indicator for power electronic converters based on their reliability. The converter reliability is represented by the proposed constant lifetime curves, which have been developed using Artificial Neural Network (ANN) under different operating conditions. Unlike the state-of-the-art theoretical reliability modeling approaches, which employ detailed electro-thermal characteristics and lifetime models of converter components, the proposed method provides a nonparametric surrogate model of the converter based on limited non-linear data from theoretical reliability analysis. The proposed approach can quickly predict the converter lifetime under given operating conditions without a further need for extended, time-consuming electro-thermal analysis. Moreover, the proposed lifetime curves can present the long-term performance of converters facilitating optimal system-level design for reliability, reliable operation and maintenance planning in power electronic systems. Numerical case studies evaluate the effectiveness of the proposed reliability modeling approach.

Investigation of long-term operation and biomass activity in a membrane bioreactor system

2011 ◽  
Vol 63 (9) ◽  
pp. 1906-1912 ◽  
Author(s):  
Simos Malamis ◽  
Andreas Andreadakis ◽  
Daniel Mamais ◽  
Constantinos Noutsopoulos
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Operating Conditions ◽  
Term Operation ◽  
Solids Retention ◽  
Biomass Activity ◽  
Long Term Performance ◽  
Term Performance

The aim of this work was to evaluate the long-term performance of a Membrane Bioreactor (MBR) that operated continuously for 2.5 years and to assess membrane fouling and biomass activity under various operating conditions. Furthermore, a method for the characterisation of influent wastewater was developed based on its separation into various fractions. The MBR system operated at the solids retention times (SRT) of 10, 15, 20 and 33 days. The increase of SRT resulted in a decrease of the fouling rate associated with the reduction of extracellular polymeric substances. Moreover, the SRT increase resulted in a significant reduction of the Oxygen Uptake Rate (OUR) due to the lower availability of substrate and in a notable decrease of the maximum OUR since high SRT allowed the development of slower growing microorganisms. Biomass consisted of small flocs due to extensive deflocculation caused by intense aeration. Finally, the method developed for wastewater characterisation is straightforward and less time consuming than the usual method that is employed.

Advanced Techniques for Establishing Long-Term Performance of Composite Repair Systems

2014 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
The United States ◽  
Operating Conditions ◽  
Repair System ◽  
Composite Repair ◽  
Design Life ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance ◽  
Composite Repairs

Although composite materials are used to repair and reinforce a variety of anomalies in high pressure transmission gas and liquid pipelines, there continues to be widespread debate regarding what constitutes a long-term composite repair. The United States regulations require that composite repairs must be able to permanently restore the serviceability of the repaired pipeline, while in contrast the Canadian regulations take a more prescriptive approach by integrating the ASME PCC-2 and ISO 24817 composite repair standards along with a requirement for establishing a 50-year design life. In this paper the author provides a framework for what should be considered in qualifying a composite repair system for long-term performance by focusing on the critical technical aspects associated with a sound composite repair. The presentation includes a discussion on establishing an appropriate composite design stress using the existing standards, using full-scale testing to ensure that stresses in the repair do not exceed the designated composite design stresses, and guidance for operators in how to properly integrate their pipeline operating conditions to establish a design life. By implementing the recommendations presented in this paper, operators will be equipped with a resource for objectively evaluating the composite repair systems used to repair their pipeline systems.

The Use of a Waste Conversion Index as a Long Term Performance Indicator for Civil Nuclear Laibilities

2003 ◽  
Author(s):  
Pauline Fawcett ◽  
David Spencer ◽  
Richard Jarvis ◽  
George Linekar
Keyword(s):  
Performance Indicator ◽  
White Paper ◽  
Predictive Tool ◽  
Hazard Reduction ◽  
Reduction Strategies ◽  
The Uk ◽  
Long Term Performance ◽  
Term Performance ◽  
Waste Conversion

In November 2001 the UK Government issued a statement on the future management of public sector nuclear liabilities and in its white paper “Managing the nuclear legacy” proposed the establishment of a Liabilities Management Authority, or the Nuclear Decommissioning Authority (NDA) as it is now called. With the advent of the NDA, whose aim will be to safely and cost effectively reduce nuclear liabilities, and existing Government Policy which requires systematic and progressive reduction in hazard, there is a need for some form of index to demonstrate progress. Although there are many indices in use, mainly within the chemical industry, none of these are considered suitable for this purpose. A Waste Conversion Index is currently being developed to satisfy these needs. The Waste Conversion Index will reflect an emphasis on passive safety rather than the more traditional safety analysis which focuses on risk. It is intended to be applicable across all UK civil nuclear sites and may act as one of a number of long-term performance indicators. This paper describes how the index is formulated, and the various factors used in the calculation together with its main uses including its use as a predictive tool to demonstrate progressive hazard reduction as nuclear liabilities are reduced. In addition the paper warns against the misuse of the index as a sole means of decision making in developing hazard reduction strategies, prioritising projects and allocating funding. Finally, some examples are given of its application to existing facilities.

Long-term Performance Analysis of CdTe PV module in real operating conditions

2018 ◽  
Vol 5 (11) ◽  
pp. 23210-23217 ◽  
Author(s):  
Rahul Rawat ◽  
S.C. Kaushik ◽  
O.S. Sastry ◽  
Birinchi Bora ◽  
Y.K. Singh
Keyword(s):  
Performance Analysis ◽  
Operating Conditions ◽  
Pv Module ◽  
Long Term Performance ◽  
Term Performance

Tertiary nitrification in aerated pilot biofilters

1994 ◽  
Vol 29 (10-11) ◽  
pp. 53-60 ◽  
Author(s):  
M. Tschui ◽  
M. Boller ◽  
W. Gujer ◽  
J. Eugster ◽  
C. Mäder ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Nitrification Rate ◽  
Measured Temperature ◽  
Exponential Relationship ◽  
Effluent Quality ◽  
Different Types ◽  
Long Term Performance ◽  
Term Performance

Three different types of internally aerated pilot scale biofilters were operated as tertiary nitrification systems. Long-term performance of the three aerated biofilters was tested under various operating conditions. The maximum volumetric nitrification rates under non NH4-limiting conditions for the three aerated biofilter systems were investigated. Based on measured temperature dependencies, an exponential relationship was established enabling the prediction of the nitrification rates at desired temperatures. Based on a temperature of 10°C, the results allow a comparison between the surface and volume specific nitrification rates in the tested biofilters as a function of the NH4 effluent concentration. As shown by experiments, nitrification performance depends on water as well as air velocities in the filter. Higher velocities of both air and water increase the nitrification rate. However, they also increase the head loss and thus decrease the filter run time. Therefore, the optimal operating conditions depend also on the filter media and the required effluent quality. Compared to fully O2-limiting operating conditions, nitrification performance during a period under partially NH4-limiting conditions clearly decreased in all tested biofilters.

scholarly journals A Review of the Degradation of Photovoltaic Modules for Life Expectancy

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4278
Author(s):  
Jaeun Kim ◽  
Matheus Rabelo ◽  
Siva Parvathi Padi ◽  
Hasnain Yousuf ◽  
Eun-Chel Cho ◽  
...  
Keyword(s):  
Life Expectancy ◽  
Operating Conditions ◽  
Real Field ◽  
Economic Losses ◽  
Stress Tests ◽  
Pv Systems ◽  
Pv Module ◽  
Long Term Performance ◽  
Term Performance

Photovoltaic (PV) modules are generally considered to be the most reliable components of PV systems. The PV module has a high probability of being able to perform adequately for 30 years under typical operating conditions. In order to evaluate the long-term performance of a PV module under diversified terrestrial conditions, outdoor-performance data should be used. However, this requires a wait of 25 years to determine the module reliability, which is highly undesirable. Thus, accelerated-stress tests performed in the laboratory by mimicking different field conditions are important for understanding the performance of a PV module. In this paper, we discuss PV-module degradation types and different accelerated-stress types that are used to evaluate the PV-module reliability and durability for life expectancy before using them in the real field. Finally, prevention and correction measures are described to minimize economic losses.

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance
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