Thanks for respond, but i don't know how to change the initial state of gen1.syn1.Sn.
I am a beginner, can you please tell me how.

Hi,
I tried to simulate IEEE 9 bus power system in openmodelica, but each time i run the simulation i got the following error message:

division by zero at time 0, (a=100) / (b=0), where divisor b expression is: gen1.Syn1.Sn
simulation terminated by an assertion at initialization
Simulation process failed. Exited with code -1.

Can any one give me an idea about how to avoid this problem. Thanks in adavance