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How to find weak voltage buses after a larger generation loss during dynamic simulation?

asked 2020-08-27 01:23:16 -0500

ShaHe23 gravatar image

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

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answered 2020-09-04 10:43:09 -0500

jconto gravatar image

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.

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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.

ShaHe23 gravatar imageShaHe23 ( 2020-09-08 01:59:58 -0500 )edit

Yes, model UVUFBLU1 can be used for that, but use latest version of PSSe, like v.33.12.2 9 since v.33.12.1 was found to have a bug about it.

jconto gravatar imagejconto ( 2020-09-08 08:20:08 -0500 )edit

answered 2020-08-27 09:38:22 -0500

perolofl gravatar image

You can report all buses with voltages below a certain limit, for example 90% voltage:

psspy.vchk(0,1, 0.9, 2.0)
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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?

ShaHe23 gravatar imageShaHe23 ( 2020-09-03 04:46:46 -0500 )edit

answered 2020-09-04 07:05:43 -0500

You need create udm to monitor all buses and records lowest one at each time step.

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Asked: 2020-08-27 01:23:16 -0500

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Last updated: Sep 04