inconsistent simulation results

answered Dec 7 '15

SqFKYo
126 ●4

Could you be more specific please?

Have you tried to record the commands you're inputting into a Python file and then replaying them, to see if the results differ?

answered Dec 16 '15

Eli Pack
761 ●2 ●10 ●20

It is great if your solution doesn't blow up and you never need to flat start, but sometimes you can try alternative solving functions to get your case back to a normal state. Try the below function rather than a typical single solve.

def solve():
    """
    Function to run Newton-Raphson load flow. If the original solve is unsuccessful, several more attempts are made with alternative parameters.

    Returns True only if the case is solved without ignoring reactive limits.
    """
    # Allow 200 iterations
    psspy.solution_parameters_3([_i,200,_i],[_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f,_f])

    # Normal full newton
    psspy.fnsl([1,0,0,1,1,0,99,0])
    reactive_ignored = False

    if psspy.solved() != 0:
        # If normal full newton didn't work:
        # Flat start decoupled
        psspy.fdns([0,0,0,1,1,1,99,0])
        if psspy.solved() == 0:
            # If flat start worked, now do a full netwon
            psspy.fnsl([0,0,0,1,1,0,99,0])
        else:
            psspy.fdns([1,0,0,1,1,1,99,0])
            psspy.fnsl([0,0,0,1,1,0,99,0])
            psspy.fnsl([1,0,0,1,1,0,99,0])
            # Try ignoring reactive limits
            if psspy.solved > 0:
                reactive_ignored = True
                psspy.fnsl([1,0,0,1,1,1,-1,0])
            psspy.fnsl([0,0,0,1,1,0,99,0])
            if psspy.solved() == 0:
                reactive_ignored = False

            if psspy.solved > 0:
                psspy.fdns([1,0,0,1,1,1,-1,0])
                reactive_ignored = True

    if psspy.solved() == 0:
        psspy.fdns([0,0,0,1,1,1,99,0])
        if reactive_ignored:
            print "\nSolved successfully, but reactive limits were ignored."
            return False
        else:
            print "\nSolved successfully!"
            return True
    else:
        print "\nUnable to solve case."
        return False