TY - GEN
T1 - On the Relationship between Ultra Low Frequency Oscillation and Power System Inertia
AU - Seppänen, Janne
AU - Lehtonen, Matti
AU - Kuivaniemi, Mikko
AU - Haarla, Liisa
N1 - Publisher Copyright:
© 2023 IEEE.
PY - 2023
Y1 - 2023
N2 - In recent years, ultra low frequency oscillation (ULFO) has been observed in various power systems. In the ULFO phenomenon, the frequency of the system continuously slowly oscillates around the nominal value. Such oscillation exists also in the Nordic power system, where the frequency of the system oscillates around the nominal 50 Hz value with a period of around 40 to 90 s. Such oscillation deteriorates the frequency quality of the system, might cause unnecessary control actions and wear and tear of turbines, and potentially even risk the frequency stability of the system. This paper analyses the characteristics of the ULFO during the latest seven years in the Nordic power system. The paper shows, based on measurements, that the ULFO has a relationship with the inertia of the system. More specifically, system inertia is clearly correlated with the frequency of the ULFO. As the inertia of the system increases, the frequency of the ULFO decreases, and vice versa. Furthermore, the amplitude of the ULFO is also correlated with inertia and smaller inertia leads to higher amplitude of the ULFO. These findings give important insight into the characteristics of ULFOs and similar analysis is also recommended for other power systems experiencing an ULFO phenomenon.
AB - In recent years, ultra low frequency oscillation (ULFO) has been observed in various power systems. In the ULFO phenomenon, the frequency of the system continuously slowly oscillates around the nominal value. Such oscillation exists also in the Nordic power system, where the frequency of the system oscillates around the nominal 50 Hz value with a period of around 40 to 90 s. Such oscillation deteriorates the frequency quality of the system, might cause unnecessary control actions and wear and tear of turbines, and potentially even risk the frequency stability of the system. This paper analyses the characteristics of the ULFO during the latest seven years in the Nordic power system. The paper shows, based on measurements, that the ULFO has a relationship with the inertia of the system. More specifically, system inertia is clearly correlated with the frequency of the ULFO. As the inertia of the system increases, the frequency of the ULFO decreases, and vice versa. Furthermore, the amplitude of the ULFO is also correlated with inertia and smaller inertia leads to higher amplitude of the ULFO. These findings give important insight into the characteristics of ULFOs and similar analysis is also recommended for other power systems experiencing an ULFO phenomenon.
KW - Frequency stability
KW - inertia
KW - mode meter
KW - ultra low frequency oscillation
UR - http://www.scopus.com/inward/record.url?scp=85174688267&partnerID=8YFLogxK
U2 - 10.1109/PESGM52003.2023.10252658
DO - 10.1109/PESGM52003.2023.10252658
M3 - Conference article in proceedings
AN - SCOPUS:85174688267
T3 - IEEE Power and Energy Society General Meeting
BT - 2023 IEEE Power and Energy Society General Meeting, PESGM 2023
PB - IEEE
T2 - IEEE Power and Energy Society General Meeting
Y2 - 16 July 2023 through 20 July 2023
ER -
