Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 172) Show all publications
Nilsson, M., Söder, L., Olauson, J., Eriksson, R., Nordström, L. & Ericsson, G. N. (2018). A Machine Learning Method Creating Network Models Based on Measurements. In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC): . Paper presented at 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC). IEEE
Open this publication in new window or tab >>A Machine Learning Method Creating Network Models Based on Measurements
Show others...
2018 (English)In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC), IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Network models are essential to perform power flow analyses. In this paper a supervised regression method creating simplified network models using measurements is presented. It is an iterative method creating a network model by minimizing the difference between measurements and obtained power flow using measured net-exchanges for each node. The method is tested in a case study for the Nordic Synchronous Area considering each bidding zone as a node. The simplified network model is created using a training set and is validated using various validation methods. The obtained reactances are not correct in absolute terms; however results indicate that the obtained power flows using the created network model are accurate enough for several different applications.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Machine learning, Nordic Power System, power flow analyses, simplified network model
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-238162 (URN)10.23919/PSCC.2018.8442822 (DOI)000447282400121 ()2-s2.0-85054003071 (Scopus ID)
Conference
2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)
Note

QC 20181107

Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-11-07Bibliographically approved
Yiming, W., Nordström, L., Wang, Y. & Hauser, C. (2018). Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications. In: Power Systems Computation Conference (PSCC2018): . Paper presented at 20th Power Systems Computation Conference (PSCC2018), 11th-15th June 2018, Dublin, Ireland. IEEE conference proceedings
Open this publication in new window or tab >>Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications
2018 (English)In: Power Systems Computation Conference (PSCC2018), IEEE conference proceedings, 2018Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
IEEE conference proceedings, 2018
Keywords
Adaptive Scheme, Cyber-Security, Quality of Service, Stateful Data Delivery Service, WAMC
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-230616 (URN)000447282400215 ()
Conference
20th Power Systems Computation Conference (PSCC2018), 11th-15th June 2018, Dublin, Ireland
Note

QC 2018-06-25

Available from: 2018-06-13 Created: 2018-06-13 Last updated: 2018-11-05Bibliographically approved
Wu, Y., Nordström, L., Wang, Y. & Hauser, C. (2018). Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications. In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC): . Paper presented at 2018 Power Systems Computation Conference (PSCC). IEEE
Open this publication in new window or tab >>Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications
2018 (English)In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC), IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Smart Grid integrates power systems and communication systems to support intelligent control and operation applications. The inputs of those applications are normally measured data collected anywhere in the system and they are transmitted over Wide Area Networks (WAN). Challenges associated with Quality of Service (QoS) and cyber-security in the delivery of these data need to be addressed. In most research work in Smart Grid, QoS and cyber-security are considered separately. However, there is tension between the two: in order to maintain a certain level of QoS security might have to be compromised. The relationship is not, however, deterministic as both QoS and the performance of cyber-security countermeasures may vary over time. To address such challenges, this paper proposes a novel adaptive cyber-security scheme. It quantifies experts opinions of available cyber-security algorithms into a metric called security coverage. Then security coverage is adaptively optimized, by switching cyber-security algorithms, depending on observed data link QoS performance. The scheme is validated with simulation studies on a typical Wide Area Monitoring Control (WAMC) application, power oscillation damping control. The proposed adaptive cyber-security scheme is generally applicable to Smart Grid or power system applications that face varying communication performance during operation.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Adaptive Scheme, Cyber-Security, Quality of Service, Stateful Data Delivery Service, WAMC
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-238164 (URN)10.23919/PSCC.2018.8450583 (DOI)000447282400215 ()2-s2.0-85054028740 (Scopus ID)
Conference
2018 Power Systems Computation Conference (PSCC)
Note

QC 20181107

Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-11-07Bibliographically approved
Wu, Y., Nordström, L., Wang, Y. & Hauser, C. (2018). Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications. In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC): . Paper presented at 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC). IEEE
Open this publication in new window or tab >>Adaptive Cyber-Security Scheme Incorporating QoS Requirements for WAMC Applications
2018 (English)In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC), IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Smart Grid integrates power systems and communication systems to support intelligent control and operation applications. The inputs of those applications are normally measured data collected anywhere in the system and they are transmitted over Wide Area Networks (WAN). Challenges associated with Quality of Service (QoS) and cyber-security in the delivery of these data need to be addressed. In most research work in Smart Grid, QoS and cyber-security are considered separately. However, there is tension between the two: in order to maintain a certain level of QoS security might have to be compromised. The relationship is not, however, deterministic as both QoS and the performance of cyber-security countermeasures may vary over time. To address such challenges, this paper proposes a novel adaptive cyber-security scheme. It quantifies experts opinions of available cyber-security algorithms into a metric called security coverage. Then security coverage is adaptively optimized, by switching cyber-security algorithms, depending on observed data link QoS performance. The scheme is validated with simulation studies on a typical Wide Area Monitoring Control (WAMC) application, power oscillation damping control. The proposed adaptive cyber-security scheme is generally applicable to Smart Grid or power system applications that face varying communication performance during operation.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Adaptive Scheme, Cyber-Security, Quality of Service, Stateful Data Delivery Service, WAMC
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-238165 (URN)10.23919/PSCC.2018.8450583 (DOI)000447282400194 ()2-s2.0-85054028740 (Scopus ID)
Conference
2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)
Note

QC 20181107

Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-11-07Bibliographically approved
Paridari, K., Nordström, L. & Sandels, C. (2018). Aggregator strategy for planning demand response resources under uncertainty based on load flexibility modeling. In: 2017 IEEE International Conference on Smart Grid Communications, SmartGridComm 2017: . Paper presented at 2017 IEEE International Conference on Smart Grid Communications, SmartGridComm 2017, Dresden, Germany, 23 October 2017 through 26 October 2017 (pp. 338-343). Institute of Electrical and Electronics Engineers (IEEE), Article ID 8340694.
Open this publication in new window or tab >>Aggregator strategy for planning demand response resources under uncertainty based on load flexibility modeling
2018 (English)In: 2017 IEEE International Conference on Smart Grid Communications, SmartGridComm 2017, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 338-343, article id 8340694Conference paper, Published paper (Refereed)
Abstract [en]

Nowadays, end-users can participate in demand response (DR) programs, and even slight load reductions from many houses can add up to major load shifts in the power system. Aggregators, which act as mediators between end-users and distribution system operator (DSO), play an important role here. The aggregator contracts the end-users for DR programs, plans ahead for times when customers should shift their load, and controls the load shifts in the running time. In this paper, our main focus is on planning the end-users for load shifting. Here, we first define and formulate the flexibilities (e.g., Stamina, repetition, and capacity) related to the dynamic loads such as space heating systems (SHSs) in detached houses. Assuming some end-users being contracted for DR program, based on estimation of their house characteristics and load flexibilities, an algorithm is then proposed to plan the SHSs for load shifting. In this algorithm the states in which a flexible load can be planned, kept in backup, or unavailable are considered by the aggregator. Another algorithm has been proposed here to deal with the different sources of uncertainties (which cause some of the planned SHSs to become unavailable). Numerical results are presented at the end, which discuss performance of the proposed strategy in terms of load flexibilities, load shifts in response to DR signals, and sensitivity analysis. Here, how to estimate the houses characteristics is a difficult issue, and we approximate them based on available models in the literature.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
National Category
Engineering and Technology Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-226678 (URN)10.1109/SmartGridComm.2017.8340694 (DOI)2-s2.0-85051029519 (Scopus ID)9781538640555 (ISBN)
Conference
2017 IEEE International Conference on Smart Grid Communications, SmartGridComm 2017, Dresden, Germany, 23 October 2017 through 26 October 2017
Note

QC 20180515

Available from: 2018-04-24 Created: 2018-04-24 Last updated: 2018-09-05Bibliographically approved
Jürgensen, J. H., Nordström, L., Hilber, P., Andreasson, E. & Brodersson, A. L. (2018). Assessment of Explanatory Variables on the Failure Rate of Circuit Breakers Using the Proportional Hazard Model. In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC): . Paper presented at 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC). IEEE
Open this publication in new window or tab >>Assessment of Explanatory Variables on the Failure Rate of Circuit Breakers Using the Proportional Hazard Model
Show others...
2018 (English)In: 2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC), IEEE , 2018Conference paper, Published paper (Refereed)
Abstract [en]

This paper utilises the proportional hazard model to understand and quantify the impact of explanatory variables on the failure rate of circuit breakers (CB). Particularly, 4496 work orders with 2622 high voltage CBs are investigated with an occurrence of 281 major failures. Different explanatory variables such as CB type, manufacturer, preventive maintenance (PM), and others are gathered to quantify their significance and magnitude of their effect. The results present that PM has a positive impact, the number of operations within the last year a negative impact, and age has a small but negative impact on the failure rate. The CB type is not significant in all analyses which can he explained by examining the PM and age of these CB types. This paper contributes to the understanding of how explanatory variables impact the failure rate which is essential for power system asset management.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Asset management, circuit breaker reliability, failure rate, preventive maintenance, proportional hazard model
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-238161 (URN)10.23919/PSCC.2018.8442567 (DOI)000447282400052 ()2-s2.0-85053160170 (Scopus ID)
Conference
2018 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)
Note

QC 20181107

Available from: 2018-11-07 Created: 2018-11-07 Last updated: 2018-11-07Bibliographically approved
Yiming, W., Xiao, Y., Hohn, F., Nordström, L., Wang, J. & Zhao, W. (2018). Bad Data Detection Using Linear WLS and Sampled Values in Digital Substations. IEEE Transactions on Power Delivery, 33(1), 150-157, Article ID 7867789.
Open this publication in new window or tab >>Bad Data Detection Using Linear WLS and Sampled Values in Digital Substations
Show others...
2018 (English)In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 33, no 1, p. 150-157, article id 7867789Article in journal (Refereed) Published
Abstract [en]

Smart Grids employ intelligent control applications that require high quality data: fast, secure, and error free. Several researchers have focused on providing techniques for low latency and secured data links for these applications. Bad data detection is however generally provided only at the central level due to limitations in legacy technologies employed in many substations. With the introduction of IEC61850 data sharing within the substation becomes more flexible and transparent allowing more sophisticated management of data quality. Hence, this paper proposes a substation level bad data detection algorithm to facilitate also these types of requirements from applications. The algorithm is based on automatically detecting the substation topology by parsing standard substation description files and online state of circuit breakers and disconnectors. By applying linear weighted least square based state estimation algorithm, bad data from failing current transformers (CT) can be detected. By conducting the verification of different types of bad data, the results show the output of bad data detection algorithm provides higher accuracy than output from both measurement and protective CT in both static and faulty situations.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
Keywords
bad data detection, digital substation, Linear WLS, process bus, sampled values
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-222247 (URN)10.1109/TPWRD.2017.2669110 (DOI)2-s2.0-85041035552 (Scopus ID)
Note

QC 20180205

Available from: 2018-02-05 Created: 2018-02-05 Last updated: 2018-02-05Bibliographically approved
Jürgensen, J. H., Brodersson, A. L., Nordström, L. & Hilber, P. (2018). Impact Assessment of Remote Control and Preventive Maintenance on the Failure Rate of a Disconnector Population. IEEE Transactions on Power Delivery, 33(4), 1501-1509
Open this publication in new window or tab >>Impact Assessment of Remote Control and Preventive Maintenance on the Failure Rate of a Disconnector Population
2018 (English)In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 33, no 4, p. 1501-1509Article in journal (Refereed) Published
Abstract [en]

This paper presents the impact of different explanatory variables such as remote control availability and conducted preventive maintenance, among others, on failure statistics of a disconnector population in Sweden using the proportional hazard model. To do so, 2191 work orders were analysed which included 1626 disconnectors and 278 major failures. Here, the results show that the remote control availability for disconnectors - an example of such Smart Grid technology - has a negative effect on the failure rate, whereas preventive maintenance has a positive impact. It is also shown that the disconnector age is not significant and that certain disconnector types have a significant and positive correlation towards failures when compared to other disconnector types. The results increase the understanding of disconnector failures to improve asset management.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Asset management, control equipment reliability, monitoring, diagnostic measures, failure rate, failure rate estimation, preventive maintenance
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-216785 (URN)10.1109/TPWRD.2017.2710482 (DOI)000431959600001 ()2-s2.0-85046947535 (Scopus ID)
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy Storage
Note

QC 20171102

Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2018-09-27Bibliographically approved
Brodén, D., Paridari, K. & Nordström, L. (2018). Matlab applications to generate synthetic electricity load profiles of office buildings and detached houses. In: 2017 IEEE Innovative Smart Grid Technologies - Asia: Smart Grid for Smart Community, ISGT-Asia 2017: . Paper presented at 7th IEEE Innovative Smart Grid Technologies - Asia, ISGT-Asia 2017, Science Conference Centre, University of AucklandAuckland, New Zealand, 4 December 2017 through 7 December 2017 (pp. 1-6). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Matlab applications to generate synthetic electricity load profiles of office buildings and detached houses
2018 (English)In: 2017 IEEE Innovative Smart Grid Technologies - Asia: Smart Grid for Smart Community, ISGT-Asia 2017, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 1-6Conference paper, Published paper (Refereed)
Abstract [en]

In this paper we present two MATLAB applications that generate synthetic electricity load profiles for office buildings and detached houses down to 1-minute resolution. The applications have been developed using App Designer, a MATLAB environment for application development. The applications are based on consumer load models for office buildings and detached houses published in previous research work. The aim of this paper is to present an overview of the application functionalities, code design, assumptions and limitations, and examples of their potential use in power system education and research. To the author's knowledge these are the first applications which allow generating synthetic load profiles for office buildings and houses in practical and intuitive manner where building attributes can be easily configured.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
Keywords
App designer, Applications, Consumer load models, MATLAB, Synthetic load data
National Category
Building Technologies
Identifiers
urn:nbn:se:kth:diva-238207 (URN)10.1109/ISGT-Asia.2017.8378371 (DOI)2-s2.0-85049985964 (Scopus ID)9781538649503 (ISBN)
Conference
7th IEEE Innovative Smart Grid Technologies - Asia, ISGT-Asia 2017, Science Conference Centre, University of AucklandAuckland, New Zealand, 4 December 2017 through 7 December 2017
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy StorageSwedish Energy AgencyVattenfall AB
Note

QC 20181115

Available from: 2018-11-15 Created: 2018-11-15 Last updated: 2018-11-15Bibliographically approved
Armendariz, M., Johansson, C., Nordström, L., Yunta Huete, A. & García Lobo, M. (2017). A Method to Design Optimal Communication Architectures in Advanced Metering Infrastructures. IET Generation, Transmission & Distribution, 11(2), 339-346
Open this publication in new window or tab >>A Method to Design Optimal Communication Architectures in Advanced Metering Infrastructures
Show others...
2017 (English)In: IET Generation, Transmission & Distribution, ISSN 1751-8687, E-ISSN 1751-8695, Vol. 11, no 2, p. 339-346Article in journal (Refereed) Published
Abstract [en]

This paper proposes a method to determine the optimal communication architecture in advance metering infrastructures (AMI). The method starts by indicating suitable groups of meters that share similar characteristics such as distance to the secondary substation and mutual proximity. Then it connects each group of meters to the AMI-Head End through a communication architecture formed by wireless and Power Line Communication (PLC) technologies. The optimality criterion takes into account the Capital Expenditures (CAPEX), Operational Expenditures (OPEX) and the Quality of Service (QoS) in the communication architecture. The method is tested on a LV network based on real utility data provided by EU FP7 DISCERN project partners. These tests show that the method is consistent with planning foresight and can be useful to assist in the AMI communication architecture designing process.

Place, publisher, year, edition, pages
IET Digital Library, 2017
Keywords
AMI, Combinatorial Optimization, Data Concentrator, K-means, Linear Semi-Assignment Problem, PRIME, PLC, Smart Grid, Virtual Data Concentrator
National Category
Communication Systems
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-192608 (URN)10.1049/iet-gtd.2016.0481 (DOI)000396553400005 ()2-s2.0-85010837023 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 308913SweGRIDS - Swedish Centre for Smart Grids and Energy Storage
Note

QC 20170517

Available from: 2016-09-16 Created: 2016-09-16 Last updated: 2017-11-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3014-5609

Search in DiVA

Show all publications