| 1. |
- Brodersson, Anna Lilly, et al.
(författare)
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Towards health assessment : Failure analysis and recommendation of condition monitoring techniques for large disconnector populations
- 2016
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Ingår i: CIRED Workshop -. - Helsinki : Institution of Engineering and Technology. ; , s. 4-
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Konferensbidrag (refereegranskat)abstract
- Condition monitoring of power system equipment is an important part of asset management. Hence, health indices were developed to describe the equipment condition in a linguistic form with the obtained data. The development of health indices requires knowledge about the equipment population under investigation to consider all important factors. Therefore, this paper investigates the failure data of a large disconnector population to identify population characteristics such as failure modes and failure locations. The analysis showed that the functions maneuverability and current carrying are essential to monitor. Moreover, this paper discusses condition monitoring techniques for disconnector and their applicability in large populations. The paper concludes that even without cost intensive investments in condition measurements or higher preventive maintenance costs, a condition evaluation can be performed.
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| 2. |
- Jürgensen, Jan Henning, 1987-, et al.
(författare)
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A Review and Discussion of Failure Rate Heterogeneity in Power System Reliability Assessment
- 2016
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The failure rate is a reliability measure which isused for planning and operation of the power system. Thus far, average or experience based failure rates were applied to power system equipment due to their straightforward implementation. However, this approach limits the accuracy of the gained resultsand neglects the important differentiation between populationand individual failure rates. Hence, this paper discusses and demonstrates the necessity to distinguish between populationand individual failure rates and reviews the existing literature offailure rate estimation within the power system domain. The literature is categorized into statistical data driven approaches and failure rate modelling with focus on different criteria whichcan be used to describe the heterogeneity within populations. The review reveals that the environmental impact was modelled predominantly.
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| 3. |
- Jürgensen, Jan Henning, 1987-
(författare)
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Condition-based Failure Rate Modelling for Individual Components in the Power System
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The electrical power grid is one of the most important infrastructures in the modernsociety. It supplies industrial and private customers with electricity and supportsother critical infrastructures such as the water supply. Thus, it is significant that the power grid is a reliable system. However, the power system experiences a hugetransition from classical production methods such as coal and nuclear power plantsto distributed renewable energy forms such as wind energy and photovoltaic. This change to a more distributed system challenges the existing power grid as well as the traditional business models of electric utilities. Thus, cost minimization to increase profitability and improvement of the power grid to increase customer satisfactionare in the focus. One approach to increase the reliability of the grid and decrease maintenance costs is a condition-based maintenance approach which requirescondition monitoring techniques.This thesis introduces into failure rate modelling for individual power system components and develops a method to calculate individual failure rates based onthe average failure rate, failure statistics, and condition monitoring data. This approach includes the analysis of failure statistics to identify failure causes and failure locations which are population characteristics but can be utilized to describe the heterogeneity within the population. Thus, the thesis first introduces into the topic of failure analysis and heterogeneity in populations. Different factors are identified and categorized which describe the condition development of a component overtime. Then, the literature within failure rate estimation is reviewed to present the factors which are used within failure rate modelling and to outline the existingmethods which consider the individual. However, limitations are discussed which emphasize the demand for a new approach. Consequently, this thesis introduce intoa new approach for estimating the failure rate for individual components.
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| 4. |
- Jürgensen, Jan Henning, 1987-, et al.
(författare)
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Individual failure rates for transformers within a population based on diagnostic measures
- 2016
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Ingår i: Electric power systems research. - : Elsevier. - 0378-7796 .- 1873-2046. ; 141, s. 354-362
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Tidskriftsartikel (refereegranskat)abstract
- The high monetary value of a transformer has placed the transformer life-time optimization into the focus of asset management. The average failure rate has created reasonable results within reliability modeling, however, it cannot reflect the probability of failure for an individual transformer. In this paper, a method is introduced to calculate individual failure rates for a transformer population based on failure statistics and diagnostic measurements such as dissolved gas, and 2-furfuraldehyde analysis. The method is applicable to all types of components and the comprehensibility makes it effective for practical implementation. The results are evaluated against two health indices based on a weight factor and fuzzy logic. It can be observed that the presented individual failure rates are plausible representatives of the transformer's probability of failure. Therefore, the results can also be utilized for asset management decision-making.
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| 5. |
- Wallnerström, Carl Johan, et al.
(författare)
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Framework for System Analyses of Smart Grid Solutions with Examples from the Gotland Case
- 2016
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Ingår i: 2016 International Conference on Probabilistic Methods Applied to Power Systems (PMAPS). - : IEEE. - 9781509019700
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Konferensbidrag (refereegranskat)abstract
- This paper presents results from a study on the impact of smart grid solutions, which includes development of a generic framework for power system analyses. The study has been performed as one of several independent studies, part of a national governmental task on smart grid in Sweden. A large amount of weather data, along with electricity consumption and wind power generation data, have been analyzed. Achieved results from these initial analyses can be used as reference material and have also been used within case studies presented. The proposed framework is flexible and numerous combinations of scenarios are possible to define. Integration of wind and solar power, analyses of transfer limits using static or dynamic rating and energy storage can be considered as well as weather effects. Results show how power systems can handle more electricity consumption and generation. The study shows that Smart Grid solutions are beneficial for resource efficient electricity grids. Moreover, different risk levels with respect to increased load can be included. Case study results show that energy storages most of the time will be unused, but that they can be used to increase the system reliability.
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