Case convergence problem

answered Feb 26 '1

Cao Huy
173 ●10 ●12 ●20

Here are some reasons:

1. Supply-demand unbalance
2. Too much power transfer through an interface
3. Voltage control problems

I suggest:

1. balance load and generators manually, for each area.
2. run loadflow with flatstart, ignore reactive power limits.

In case there is not sensitive information in your file, I could lend you a hand.

answered Feb 22 '1

jconto
2756 ●10 ●30 ●41

Numerically non-convergence conditions due to switching back & forth of capacitors or adjusting transformer taps or conflicting voltage control objective of generators need to be cleared first. Next, check that total generation and load, in P and Q, are close enough so the swing unit could resolve the unbalance.

Find a previous case that converged, compare them to find the significant differences and adjust accordingly. For example, if there is too much load in the non-converging case, consider reducing it to a level that you can converge again and then perform a PV study to find the maximum load to increase before reaching non-convergence.

answered Feb 22 '1

perolofl
3452 ●1 ●9 ●20

Try to solve with ignore reactive power limits.

Then check the generators with reactive power overload.