How to avoid numerical oscillations in power system with synchronous machines?
4 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Good morning!
My question is apparently very simple. I would like to run a model of a power system which includes synchronous machines in steady-state and obtain constant generators' output frequencies. Since I am interested in running some tests simulating faults, I would like to start off with frequencies as constant as possible.
This can be well achieved if I run a Phasor simulation using the Powergui block, but it cannot be obtained in either a continous or discrete simulation (also Discrete Phasor simulation). I have read this article and asked for suggestions in order to limit oscillations, but all given solutions seem not to be working in my case.
At the moment, I have already tried:
- Increasing the time step of the model (from few tens of us up to 0.5 ms)
- Adding a resistive load to the terminals of each machine whose power is proportional to the time step (as suggested in the model). I have also tried adding a resistive load much bigger than the minimum one obtained from the proportionality with the time step.
- Changing the type of discrete simulation (from ode1 to higher orders)
- Changing the type of solver model for the synchronous machines (using the trapezioidal and Euler "robust" versions)
At the moment I get an oscillating frequency around 60 Hz whose peaks reach up to 60.04 and 59.96 which is clearly not ok for a steady-state case.
How can I improve this result having already tried (apparently) everything suggested? Alternatively, can I place my power system in one block and simulating it using Phasor simulation, and locate my sensor models in another block using a discrete simulation? Could that work?
Thanks a lot for your help.
2 Kommentare
PAUL SERNA TORRE
am 13 Nov. 2023
I am having the same problems. I tried all the methods you suggested, but the numerical oscillations are still there. The only way (I found) to get around this issue is using the simplified synchronous machine.
PAUL SERNA TORRE
am 13 Nov. 2023
New update: I was able to run a three-bus network with three synchronous machine pu standard without any frequency oscillation. What I did is to add a very small mechanical power to the one that the power flow determined in one machine. This very small mechanical power I found by trial and error until the frequency settle at 60 Hz for 2 seconds.
Antworten (0)
Siehe auch
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!