搭建一个模型，但是运行出现了错误，找大神求解!
MODEL Chongran2
COMMENT >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
The model of this example updates the present state of the
circuit breaker by taking into account the conditions
controlling four represented state transitions: first opening,
reigniting, reopening, and full opening.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ENDCOMMENT
INPUT U1,U2
OUTPUT RB
DATA GO{DFLT:0.8}
TAUO{DFLT:1.5e-6}
k{DFLT:2500000}
a{DFLT:0.5}
v{DFLT:300}
VAR I,RB,G1,G1b,G2,G2b,RB1,RB2,P0,TAU1,TAU2
INIT
RB:=1 / GO
G1:=2*GO
G2:=2*GO
ENDINIT
EXEC
I:=(U1-U2)/RB
IF (ABS(I) > 1.E - 12) THEN
P0:=k*((1/RB)**a)*(1.535*0.0001*(v**2)-0.0505*v+5.842)
TAU1:=TAUO*((1/RB)**0.17)
G1b:=((I**2.)/(P0)-G1)*(1. - 1./ EXP(1. - timestep / TAU1))
TAU2:=TAUO*((1/RB)**0.17)
G2b:=((I**2.)/(G2*((2.3025*0.001*(v**2)-0.7575*v+87.63)**2))-G2)*(1. - 1./ EXP(1. - timestep/TAU2))
RB1:=1./ABS(G1+G1b)
RB2:=1./ABS(G2+G2b)
G1:=1./RB1
G2:=1./RB2
RB:=ABS(RB1+RB2)
ENDIF
ENDEXEC
ENDMODEL
