Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Elkvalitet kopplad till fördelningsstationer - En studie om förnybara energikällors påverkan på mellanspänningsnätet

Lindgren, Nora LU (2025) In CODEN:LUTEDX/TEIE EIEL05 20251
Industrial Electrical Engineering and Automation
Abstract (Swedish)
Integrationen av variabel elproduktion, såsom sol- och vindkraft, i elnätet bli allt vanligare. Det leder till utmaningar i form av spänningsvariationer, försämrad stabilitet och lägre elkvalitet. En möjlig lösning är energilagring, som kan stödja elnätet genom tjänster som peak-shaving och frekvensreglering, vilket bidrar till stabilisering och effektivare energianvändning.

Begreppet elkvalitet omfattar olika kriterier för en störningsfri leverans av el. Vanliga störningskällor är övertoner, flimmer, transienter och spänningsvariationer. Fördelningsstationer, som tar emot högspänning från transmissionsnätet och omvandlar den till lägre spänning för lokal distribution, är centrala för elkvaliteten.

Detta examensarbete undersöker... (More)
Integrationen av variabel elproduktion, såsom sol- och vindkraft, i elnätet bli allt vanligare. Det leder till utmaningar i form av spänningsvariationer, försämrad stabilitet och lägre elkvalitet. En möjlig lösning är energilagring, som kan stödja elnätet genom tjänster som peak-shaving och frekvensreglering, vilket bidrar till stabilisering och effektivare energianvändning.

Begreppet elkvalitet omfattar olika kriterier för en störningsfri leverans av el. Vanliga störningskällor är övertoner, flimmer, transienter och spänningsvariationer. Fördelningsstationer, som tar emot högspänning från transmissionsnätet och omvandlar den till lägre spänning för lokal distribution, är centrala för elkvaliteten.

Detta examensarbete undersöker vilka av de fyra elkvalitetsparametrarna som påverkas vid fördelningsstationer, samt vilka faktorer – såsom producerad effekt, avstånd och belastning – som har störst inverkan. Arbetet har genomförts på Lunds Tekniska Högskola i samarbete med Sweco.

Utförande av arbetet har bestått av litteraturstudier, intervjuer och simuleringar i programmet DIg SILENT PowerFactory. En modell av ett mellanspänningsnät byggdes i simuleringsprogrammet där olika parametrars påverkan på elkvaliteten kunde undersökas.

Resultaten visar att övertoner och spänningsvariationer påverkar elkvaliteten vid fördelningsstationer i takt med ökad produktion från solceller. Däremot påverkas inte transienter och flimmer av solcellsproduktion, utan uppstår främst från andra störkällor. Analysen visar att den producerade effekten från solceller har störst påverkan på spänningsvariationer, medan avståndet mellan solceller och stationen har större betydelse för övertonsnivåerna. Dessutom visar resultaten att andelen anslutna laster påverkar både spänningsvariationer och förekomsten av övertoner, vilket ytterligare understryker vikten av en balanserad elförbrukning i elnätet. (Less)
Abstract (Swedish)
The integration of renewable energy sources such as solar and wind power is steadily increasing, which introduces challenges such as voltage fluctuations, reduced system stability, and lower power quality. Battery Energy Storage Systems (BESS) can support the grid by providing services such as frequency regulation and peak shaving, contributing to a more stable and energy-efficient power system.

Power quality refers to a range of criteria that ensure the reliable and disturbance-free delivery of electricity. Common sources of disturbances include harmonics, flicker, transients, and voltage variations. Substations, which receive high-voltage electricity from the transmission network and step it down for distribution to local networks,... (More)
The integration of renewable energy sources such as solar and wind power is steadily increasing, which introduces challenges such as voltage fluctuations, reduced system stability, and lower power quality. Battery Energy Storage Systems (BESS) can support the grid by providing services such as frequency regulation and peak shaving, contributing to a more stable and energy-efficient power system.

Power quality refers to a range of criteria that ensure the reliable and disturbance-free delivery of electricity. Common sources of disturbances include harmonics, flicker, transients, and voltage variations. Substations, which receive high-voltage electricity from the transmission network and step it down for distribution to local networks, play a key role in maintaining power quality.

This thesis investigates which of the four power quality parameters are affected at substations, as well as which factors – such as power output, distance, and load – have the greatest influence. The project was conducted at Lund University of Technology in collaboration with Sweco.

The methodology included literature reviews, interviews, and simulations in DIgSILENT PowerFactory. A model of a medium-voltage grid was built in the simulation environment to analyze how various parameters affect power quality.

The results show that harmonics and voltage variations impact power quality at substations as solar power production increases. In contrast, transients and flicker are not caused by solar generation but arise primarily from other sources. The analysis indicates that the amount of power produced by solar cells has the greatest influence on voltage variations, while the distance between the solar installation and the substation has a more significant effect on harmonic levels. Additionally, the proportion of connected loads influences both voltage variations and the occurrence of harmonics, highlighting the importance of maintaining balanced electricity consumption within the grid. (Less)
Please use this url to cite or link to this publication:
author
Lindgren, Nora LU
supervisor
organization
alternative title
Power quality related to primary substations - A study on the impact of renewable energy sources on the medium-voltage grid
course
EIEL05 20251
year
type
M2 - Bachelor Degree
subject
publication/series
CODEN:LUTEDX/TEIE
report number
3146
language
Swedish
id
9200567
date added to LUP
2025-06-23 16:51:51
date last changed
2025-06-23 16:51:51
@misc{9200567,
  abstract     = {{The integration of renewable energy sources such as solar and wind power is steadily increasing, which introduces challenges such as voltage fluctuations, reduced system stability, and lower power quality. Battery Energy Storage Systems (BESS) can support the grid by providing services such as frequency regulation and peak shaving, contributing to a more stable and energy-efficient power system.

Power quality refers to a range of criteria that ensure the reliable and disturbance-free delivery of electricity. Common sources of disturbances include harmonics, flicker, transients, and voltage variations. Substations, which receive high-voltage electricity from the transmission network and step it down for distribution to local networks, play a key role in maintaining power quality.

This thesis investigates which of the four power quality parameters are affected at substations, as well as which factors – such as power output, distance, and load – have the greatest influence. The project was conducted at Lund University of Technology in collaboration with Sweco.

The methodology included literature reviews, interviews, and simulations in DIgSILENT PowerFactory. A model of a medium-voltage grid was built in the simulation environment to analyze how various parameters affect power quality.

The results show that harmonics and voltage variations impact power quality at substations as solar power production increases. In contrast, transients and flicker are not caused by solar generation but arise primarily from other sources. The analysis indicates that the amount of power produced by solar cells has the greatest influence on voltage variations, while the distance between the solar installation and the substation has a more significant effect on harmonic levels. Additionally, the proportion of connected loads influences both voltage variations and the occurrence of harmonics, highlighting the importance of maintaining balanced electricity consumption within the grid.}},
  author       = {{Lindgren, Nora}},
  language     = {{swe}},
  note         = {{Student Paper}},
  series       = {{CODEN:LUTEDX/TEIE}},
  title        = {{Elkvalitet kopplad till fördelningsstationer - En studie om förnybara energikällors påverkan på mellanspänningsnätet}},
  year         = {{2025}},
}