# reattempt solve if iteration limit is reached

How can I reattempt to solve using the full newton raphson method when the 20 iteration limit is reached?

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How can I reattempt to solve using the full newton raphson method when the 20 iteration limit is reached?

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2

To do this programmatically, I use the `solved`

function. It looks at the last solution and returns an error code > 0 if there was a problem and returns 0 for no problem.

Assuming you have `psspy.throwPsseExceptions = True`

near the start of your file:

```
import psspy
psspy.throwPsseExceptions = True
ITERATION_LIMIT = 1
def solve_and_reattempt(attempts=3):
for attempt in range(attempts):
try:
return psspy.fnsl()
except psspy.FnslError:
# an error solving, if iteration limit reached resolve
if psspy.solved() == ITERATION_LIMIT:
continue
# else re-raise Error
else:
raise
```

and you would use the `solve_and_reattempt`

function like this:

```
solve_and_reattempt(attempts=2)
```

3

Hi JervisW,

You may increase the maximum number of iterations to something like 100 or more: Power Flow > Solution > Parameters > ITMXN

regards, chiangm

Asked: **
2012-01-05 01:05:44 -0500
**

Seen: **704 times**

Last updated: **Jan 15 '12**

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