Estimation of Inertia in Power Systems Using Electromechanical Modes
(2020) In CODEN:LUTEDX/TEIE EIEM01 20201Industrial Electrical Engineering and Automation
- Abstract
- The transition to more renewable energy such as wind, leads to a decreased inertia in the power system. As a consequence of this, disturbances lead to larger frequency deviations and the frequency stability of the system is worsened. Therefore, there is a surging interest to estimate the inertia in the power system.
In this thesis, a novel method for inertia estimation is proposed and investigated. It is based on the electromechanical modes of the system. The modes are estimated from measurements, a system model is constructed, and the inertia is found such that the modes of the model correspond to the estimated modes. This divides the method into two parts. One is the estimation of modes, and one is the estimation of inertia from the... (More) - The transition to more renewable energy such as wind, leads to a decreased inertia in the power system. As a consequence of this, disturbances lead to larger frequency deviations and the frequency stability of the system is worsened. Therefore, there is a surging interest to estimate the inertia in the power system.
In this thesis, a novel method for inertia estimation is proposed and investigated. It is based on the electromechanical modes of the system. The modes are estimated from measurements, a system model is constructed, and the inertia is found such that the modes of the model correspond to the estimated modes. This divides the method into two parts. One is the estimation of modes, and one is the estimation of inertia from the modes. Furthermore, there is a division between the slow rigid body mode of the entire system and the faster inter-generator modes. Both are possible to use in the method. The former is harder to estimate, while the latter are more difficult to use for inertia estimation.
The mode estimation was investigated by testing estimation methods on simulated systems where the true modes were known. The inertia estimation from the modes was performed by an optimisation routine in PowerFactory, and several systems with a few generators were analysed.
It was concluded that it was possible to estimate the modes in the simulations, at least if they were not too damped. The accuracy was in the range of 10% for the imaginary part of the rigid body mode, and higher for the inter-generator modes.
The rigid body mode was highly valuable for inertia estimation, and the total system inertia could be determined with approximately the same accuracy as the mode could be estimated. Using the imaginary part and the mode shape of inter-generator modes, it was possible to estimate the total inertia with approximately 10% standard deviation. Typically, a few inter-generator modes sufficed for estimation.
Combining the two parts of the method and testing it on the IEEE 14-bus and 39-bus test system with added hydro governors showed that inertia estimation from the electromechanical modes was possible.
The achieved accuracy compares well with what has been achieved with other methods and shows that this method has potential. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9019783
- author
- Johnsson, Vidar LU
- supervisor
- organization
- course
- EIEM01 20201
- year
- 2020
- type
- H3 - Professional qualifications (4 Years - )
- subject
- publication/series
- CODEN:LUTEDX/TEIE
- report number
- 5445
- language
- English
- id
- 9019783
- date added to LUP
- 2021-04-27 14:25:49
- date last changed
- 2021-04-27 14:25:49
@misc{9019783,
abstract = {{The transition to more renewable energy such as wind, leads to a decreased inertia in the power system. As a consequence of this, disturbances lead to larger frequency deviations and the frequency stability of the system is worsened. Therefore, there is a surging interest to estimate the inertia in the power system.
In this thesis, a novel method for inertia estimation is proposed and investigated. It is based on the electromechanical modes of the system. The modes are estimated from measurements, a system model is constructed, and the inertia is found such that the modes of the model correspond to the estimated modes. This divides the method into two parts. One is the estimation of modes, and one is the estimation of inertia from the modes. Furthermore, there is a division between the slow rigid body mode of the entire system and the faster inter-generator modes. Both are possible to use in the method. The former is harder to estimate, while the latter are more difficult to use for inertia estimation.
The mode estimation was investigated by testing estimation methods on simulated systems where the true modes were known. The inertia estimation from the modes was performed by an optimisation routine in PowerFactory, and several systems with a few generators were analysed.
It was concluded that it was possible to estimate the modes in the simulations, at least if they were not too damped. The accuracy was in the range of 10% for the imaginary part of the rigid body mode, and higher for the inter-generator modes.
The rigid body mode was highly valuable for inertia estimation, and the total system inertia could be determined with approximately the same accuracy as the mode could be estimated. Using the imaginary part and the mode shape of inter-generator modes, it was possible to estimate the total inertia with approximately 10% standard deviation. Typically, a few inter-generator modes sufficed for estimation.
Combining the two parts of the method and testing it on the IEEE 14-bus and 39-bus test system with added hydro governors showed that inertia estimation from the electromechanical modes was possible.
The achieved accuracy compares well with what has been achieved with other methods and shows that this method has potential.}},
author = {{Johnsson, Vidar}},
language = {{eng}},
note = {{Student Paper}},
series = {{CODEN:LUTEDX/TEIE}},
title = {{Estimation of Inertia in Power Systems Using Electromechanical Modes}},
year = {{2020}},
}