Benefits of failure statistics and measurement equipment for maintenance planning: Case study - Capacitor voltage transformers and circuit breakers in the transmission grid swegrids-logo

SweGRIDS research area Controllable Power Components
SweGRIDS project code CPC16
Project type PostDoc
Status running
Researcher Per Westerlund   (webpage)
University KTH (EME)
Project period 2020-07-01 to 2021-12-31   
Project supervisor Patrik Hilber   (webpage)
Industrial sponsors Svenska kraftnät


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Project abstract

In order to monitor the electric grid, tens of voltage measurements are made in each substation. As the transmission grid has high voltages (400 or 220 kV), the measurement starts by reducing the voltage, using a voltage divider (a stack of capacitors) and then a transformer. Thus, the measurement devices are called capacitive voltage transformers (CVTs). However, the capacitors can break due to aging together with lightning and switching overvoltages. If several capacitors in a stack have already broken, the voltage across the remaining ones will be too high and some more will most likely break, leading to an avalanche and a total failure.

Svenska kraftnät has about 1600 CVTs in Sweden's transmission grid. In the summer of 2014, six CVTs exploded due to successive failures of capacitors. The usual condition measurement of a CVT includes a measurement of the capacitance, which requires an outage. However, an existing energy measurement system can be used to detect short-circuited capacitors thanks to a new algorithm. Hence, the project consists in evaluating this algorithm. It is also interesting to determine when it is useful to extend the monitoring and which CVTs fail more often.

Another part of the project consists in finishing the evaluation of the work orders of disconnectors and circuit breakers. In the previous SweGRIDS project FPS7, the work orders from Svenska kraftnät were extracted from the maintenance database together with information about the type, the geographic position, the function in the grid, the technology and the voltage level. The result can be a change in the maintenance plans.


Summary of work

The circuit breakers were classified according to type and manufacturer, function in the grid and operating environment. Also, the number of operations was incorporated into the statistical analysis. There was a need to look for missing data, to standardise type denominations and to merge different types from the same producer. Several distributions have been tried (Poisson, generalised Poisson and negative binomial). The disconnectors will be analysed in the same way.

A master thesis about condition monitoring of disconnectors was finished. The system continues to record more operations, which will provide data for an article. A literature study about failures of CVTs has been done and the first failed capacitors have been detected.


Event log


Project reference-group

Tommie Lindquist,  Svenska kraftnät
Milan Radosavljević,  Svenska kraftnät
Ebrahim Shayesteh,  Svenska kraftnät
Claes Ahlrot,  Eon
Ola Ivarsson,  Eon
Johan Öckerman,  Vattenfall
Fredrik Carlsson,  Vattenfall
Erik Jenelius,  Trafik och logistik KTH
Erik Lejerskog,  Ellevio
Pernilla Owe,  Ellevio
Tor Laneryd,  Hitachi ABB Power Grids


Publications by this researcher

See alternatively the researcher's full DiVA list of publications, with options for sorting.
Publications in journals and conferences usually will not show until a while after they are published.

Investments in data quality : Evaluating impacts of faulty data on asset management in power systems
Sylvie Evelyne Koziel,   Patrik Hilber,   Per Westerlund,   Ebrahim Shayesteh.
2021,   Applied Energy, vol. 281

CIGRE JWG A3.43 progress report “Tools for lifecycle management of T&D switchgear based on data from condition monitoring systems"
Nicola Gariboldi,   Javier Mantilla,   Dan Catanese,   Sébastien Poirier,   Ryszard Pater,   Alexander Herrera,   Andreas Nenning,   Per Westerlund.
2020,   Cigré Canada conference

Reliability and Cost-Effectiveness Analysis of Various HV Substation Configurations
Aleksandar Boričić,   Dhruv Bhatt,   Per Westerlund.
2019,   14e congrès annuel de CIGRE Canada 14th annual congress of Cigre Canada, September 16-19, 2019

Extreme Value Analysis of Power System Data
Per Westerlund,   Wadih Naim.
2019,   ITISE 2019 - International Conference on Time Series and Forecasting, 25-27 September 2019 Granada (Spain)

Forecasting cross-border power exchanges through an HVDC line using dynamic modelling
Sylvie Evelyne Koziel,   Patrik Hilber,   Per Westerlund,   E. Shayesteh.
2019,   2019 IEEE International Conference on Big Data, Big Data 2019, 9 December 2019 through 12 December 2019

Non-intrusive methods for condition assessment of distribution and transmission switchgear
Nenad Uzelac,   Christian Heinrich,   Ryszard Pater,   Jack Arnold,   Daniel Eichhoff,   Venanzio Ferraro,   Nicola Gariboldi,   Mario Germain,   Alejandro Gioseffi,   Takashi Ito,   Petr Kopejtko,   Albert Livshitz,   José López-Roldán,   Jason MacLeod,   Javier Mantilla,   Ana Milosevic,   Sébastien Poirier,   Bernd Schuepferling,   Rene Smeets,   Johan Smit,   Erik Taylor,   Theo van Rijn,   Xiaohua Wang,   Per Westerlund.

Prediction of high current for thermography in maintenance of electrical networks
Per Westerlund,   Jesper Rydén,   Patrik Hilber,   Tommie Lindquist.
2018,   27th Nordic Conference in Mathematical Statistics

Prediction of Current by Artificial Neural Networks in a Substation in order to Schedule Thermography
Per Westerlund,   Ilias Dimoulkas.
2018,   International conference on Time Series and Forecasting, September 19th-21th, 2018

Condition measuring and lifetime modelling of disconnectors, circuit breakers and other electrical power transmission equipment
Per Westerlund.
2017,   Thesis (PhD), Kungliga Tekniska högskolan, TRITA-EE 2017:134

Condition monitoring of disconnectors in the electric power transmission grid with temperature sensors
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2016,   International Journal of Industrial and Systems Engineering, vol. 23(1)

Prediction of time for preventive maintenance
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2016,   Nordstat 2016,26th Nordic Conference in Mathematical Statistics, June 27 - 30, Denmark

Prediction of current in a substation in order to schedule thermography
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2016,   PMAPS 2016 2016 International Conference on Probabilistic Methods Applied to Power Systems Oct. 16-20, 2016 Beijing, China

Condition measuring and lifetime modelling of electrical power transmission equipment
Per Westerlund.
2015,   Thesis (Licentiate), KTH Royal Institute of Technology, TRITA-EE 2015:026

Function test and condition test for disconnecting circuit breakers
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2015,   2015 CIGRE SC A3 & B3 joint colloquium

The reliability chain
Patrik Hilber,   Per Westerlund,   Tommie Lindquist.
2015,   2015 CIGRE SC A3 & B3 joint colloquium

Reliability Data : A Review of Importance, Use, and Availability
Niklas Ekstedt,   Carl Johan Wallnerström,   Sajeesh Babu,   Patrik Hilber,   Per Westerlund,   Jan Henning Jürgensen,   Tommie Lindquist.
2014,   NORDAC 2014 (Eleventh Nordic Conference on Electricity Distribution System Management and Development, Stockholm, 8 - 9 September 2014)

Using power system temperature sensors for moreuses than originally intended : Exemplified by investigating dynamic rating possibilities
Carl Johan Wallnerström,   Per Westerlund,   Patrik Hilber.
2014,   NORDAC 2014 (Eleventh Nordic Conference on Electricity Distribution System Management and Development, Stockholm, 8 - 9 September 2014)

Grade levels for multiple-choice tests
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2014,   Nordstat 2014, Turku, Finland, 02-06 Jun 2014

A review of methods for condition monitoring, surveys and statistical analyses of disconnectors and circuit breakers
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2014,   2014 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2014, Durham, United Kingdom, 7-10 July 2014

Condition monitoring of the disconnectors in the electric power transmission grid with temperature sensors
Per Westerlund,   Patrik Hilber,   Tommie Lindquist.
2013,   MPMM 3rd International Conference on Maintenance Performance Measurement and Management, MPMM 2013, Lappeenranta, Finland, 12-13 September 2013

Benefits of Reliability Centred Asset Management
Patrik Hilber,   Carl Johan Wallnerström,   Johanna Rosenlind,   Sajeesh Babu,   Per Westerlund.
2013,   22nd International Conference and Exhibition on Electricity Distribution, CIRED 2013

Publication list last updated from DiVA on 2021-09-18 22:00.


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Page started: 2020-07-01
Last generated: 2021-09-18