Impact of Over-Frequency Events on Nordic Power Production Facilities - Simulation of Faults in HVDC Links
(2025) In CODEN:LUTEDX/TEIE EIEM01 20242Industrial Electrical Engineering and Automation
- Abstract
- Over-frequency has become an increasingly relevant issue in the Nordic synchronous power system, mainly because of the increased number of HVDC (High Voltage Direct Current) links connecting it to neighboring synchronous systems. The aim of this thesis is to research the impact that over-frequency events, caused by faults in HVDC links, have on the Nordic power system and especially what frequencies production facilities are exposed to.
The simulation model Nordic44 was used to simulate several different faults. The model has been updated and expanded to fit the current Nordic power system with more accuracy. PMU measurements from two historic events were used to validate the final simulation model. The main focus was the maximum... (More) - Over-frequency has become an increasingly relevant issue in the Nordic synchronous power system, mainly because of the increased number of HVDC (High Voltage Direct Current) links connecting it to neighboring synchronous systems. The aim of this thesis is to research the impact that over-frequency events, caused by faults in HVDC links, have on the Nordic power system and especially what frequencies production facilities are exposed to.
The simulation model Nordic44 was used to simulate several different faults. The model has been updated and expanded to fit the current Nordic power system with more accuracy. PMU measurements from two historic events were used to validate the final simulation model. The main focus was the maximum frequency and maximum RoCoF. Five different simulation cases have been studied, and each of them represents an HVDC issue that could cause an over-frequency event in the Nordic power system under different operating scenarios. Their severity level and likelihood of occurring vary greatly. To conclude how the simulation results might impact Nordic production facilities, two different Swedish regulations for generators connecting to the grid were studied. The two different regulations considered in this thesis are applicable to different power production facilities, based on the age of the facilities.
As expected, the simulations showed that a greater disturbance to the power balance during a fault will have a more noticeable impact on the power system. When comparing the results with the regulations' requirements, it was concluded that cases with a larger total power flow change will have a higher risk of generators disconnecting due to high frequency. It was also concluded that the severity of the impact on Nordic production facilities will vary with the age of the facility due to the different regulations. The newer requirements have higher frequency limits for staying connected for unlimited time, but a lower limit for immediate disconnection, compared to the older ones. The RoCoF for an over-frequency event caused by a fault in one or several HVDC links does not risk exceeding the limit for the requirements stated in the regulations. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9184486
- author
- Köhler, Agnes LU and Rydstedt, Astrid LU
- supervisor
- organization
- alternative title
- Inverkan av överfrekvens på nordiska elproduktionsanläggningar - Simulering av fel i HVDC-länkar
- course
- EIEM01 20242
- year
- 2025
- type
- H3 - Professional qualifications (4 Years - )
- subject
- publication/series
- CODEN:LUTEDX/TEIE
- report number
- 5529
- language
- English
- id
- 9184486
- date added to LUP
- 2025-02-11 11:03:24
- date last changed
- 2025-02-12 21:16:12
@misc{9184486,
abstract = {{Over-frequency has become an increasingly relevant issue in the Nordic synchronous power system, mainly because of the increased number of HVDC (High Voltage Direct Current) links connecting it to neighboring synchronous systems. The aim of this thesis is to research the impact that over-frequency events, caused by faults in HVDC links, have on the Nordic power system and especially what frequencies production facilities are exposed to.
The simulation model Nordic44 was used to simulate several different faults. The model has been updated and expanded to fit the current Nordic power system with more accuracy. PMU measurements from two historic events were used to validate the final simulation model. The main focus was the maximum frequency and maximum RoCoF. Five different simulation cases have been studied, and each of them represents an HVDC issue that could cause an over-frequency event in the Nordic power system under different operating scenarios. Their severity level and likelihood of occurring vary greatly. To conclude how the simulation results might impact Nordic production facilities, two different Swedish regulations for generators connecting to the grid were studied. The two different regulations considered in this thesis are applicable to different power production facilities, based on the age of the facilities.
As expected, the simulations showed that a greater disturbance to the power balance during a fault will have a more noticeable impact on the power system. When comparing the results with the regulations' requirements, it was concluded that cases with a larger total power flow change will have a higher risk of generators disconnecting due to high frequency. It was also concluded that the severity of the impact on Nordic production facilities will vary with the age of the facility due to the different regulations. The newer requirements have higher frequency limits for staying connected for unlimited time, but a lower limit for immediate disconnection, compared to the older ones. The RoCoF for an over-frequency event caused by a fault in one or several HVDC links does not risk exceeding the limit for the requirements stated in the regulations.}},
author = {{Köhler, Agnes and Rydstedt, Astrid}},
language = {{eng}},
note = {{Student Paper}},
series = {{CODEN:LUTEDX/TEIE}},
title = {{Impact of Over-Frequency Events on Nordic Power Production Facilities - Simulation of Faults in HVDC Links}},
year = {{2025}},
}