Case convergence problem

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Try to solve with ignore reactive power limits.

Then check the generators with reactive power overload.

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.

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.