Conference paper
Evaluation of Factorization Methods for Thévenin Equivalent Computations in Real-Time Stability Assessment
Department of Electrical Engineering, Technical University of Denmark1
Center for Electric Power and Energy, Centers, Technical University of Denmark2
Electric Power Systems, Center for Electric Power and Energy, Centers, Technical University of Denmark3
Smart Electric Components, Center for Electric Power and Energy, Centers, Technical University of Denmark4
Thevenin equivalents are used by a range of power system stability indicators, such as the L-index for voltage stability and the aperiodic small signal rotor angle stability indicator. This paper investigates the effect of using different factorization methods for computing coefficients for wide-area Thevenin equivalents.
Direct and incomplete factorization methods are compared with respect to runtime, accuracy and amount of fill-in. The paper introduces a proof that the block triangular form of bus admittance matrices will have no non-zero entries in the off-diagonal. KLU factorization is found to perform almost twice as fast as the standard LU factorization with no cost of accuracy.
It is, however, shown that the largest computational workload is associated with dense matrix multiplications. An incomplete method reduces the fill-in of coefficient matrices at the cost of accuracy in Thevenin voltages. It is shown, that inaccuracies are amplified as the L-index approaches the stability limit.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2018 |
| Pages: | 1-7 |
| Proceedings: | 20th Power Systems Computation Conference |
| ISBN: | 1538615835 , 1910963097 , 1910963100 , 9781538615836 , 9781910963098 and 9781910963104 |
| Types: | Conference paper |
| DOI: | 10.23919/PSCC.2018.8442893 |
| ORCIDs: | Hildebrandt, Christina , Karatas, Bahtiyar Can , Glarbo Muller, Jakob and Johannsson, Hjortur |
Power system analysis computing Power system stability indicators Real-time assessment Thevenin equivalent Wide-area monitoring
Admittance Generators KLU factorization L-index Power system stability Real-time systems Rotors Stability criteria Thevenin voltages aperiodic small signal rotor angle stability indicator bus admittance matrices coefficient matrices dense matrix multiplications direct factorization methods iterative methods matrix multiplication nonzero entries power system stability power system stability indicators real-time stability rotors stability limit standard LU factorization thévenin equivalent computations voltage stability wide-area Thevenin equivalents
