Hi everyone! I want to find weak voltage buses during dynamic simulation after tripping a larger power plant. Then shed loads from weak buses to stabilise the system. Is there a python API to find weak voltage buses? If someone can answer it will be a big help for me. Thanks in Advance
You need create udm to monitor all buses and records lowest one at each time step.
Thanks for the answer. Can you send me some reference codes for this?
You can report all buses with voltages below a certain limit, for example 90% voltage:
psspy.vchk(0,1, 0.9, 2.0)
This works but is there a way to get weak bus numbers to a file with their voltages, then read the file data and change their load amounts using Loadchng API during dynamic simulation?
It seem your problem is a UVLS study in disguise. Check the post "How to calculate the best load shedding bus?"
In a dynamic simulation, add UVLS relays to all loads in the study region (model LVSHAR for area x, use a single stage) with generic settings for the voltage level to trip, the time delay before tripping and the fraction of load to be shed. (0.9 V pu, 3 sec, 0.05).
Let the UVLS relay model find those buses with low voltages during the simulation. Then load will be shed (5% of total bus load) and the simulation continues. At the end, several buses would have load shed. Verify with a voltage scan (vchk activity) that the lowest voltage is acceptable. If not, repeat the run with a higher fraction of load to be shed, say 10%.
Local buses would have different voltage thresholds or time delays tolerances to activate the relays. A more realistic UVLS study would require to vary all three parameters (v, t, f) in 3 to 5 stages model customized to the bus load requirements, all these tested under several extreme contingencies and network conditions.
Thanks for the answer. Without using UVLS, can I use user written model UVUFBLU1 ? Because I want to shed loads considering both voltage and frequency. I have tried to implement LS by detection of df/dt & frequency deviation and shedding loads from weakest buses by checking voltage violations.
Yes, model UVUFBLU1 can be used for that, but use latest version of PSSe, like v.33.12.2 since v.33.12.1 was found to have a bug about it.
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