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发表于 2008-4-10 12:02:55
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Well, there are several source models in EMTDC/PSCAD, all ramping from 0.
. Z9 V3 w! }" [" ZThere is a ramping time you can choose. The ramping pattern can be linear, exponential or other...0 O. f% H5 G8 ]" a# d& m8 L9 Q
for instance, linear...
% O: J) y: z5 ^/ Q8 H& { G3 W" HVa=Vm*t*sinwt
: F. ]. T' e' O3 nVb=Vm*t*sin(wt-120)1 {; M$ f; U$ y o" p3 X! h, T$ E
Va=Vm*t*sin(wt+120)
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7 L$ I+ t3 p8 H7 C" Lwhen t=0, va=0, vb=0 and Vc=0 np problem.
2 x. y" K3 @# |- f* P2 M3 q7 wt can be normalized so that the magnitude can be ramp to the Vm in certain time, then stays there.
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There is no problem to implement this.
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Anyway, focusing on such small detail won't help you understand the simulation.
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/ B5 v" j4 y: y. YIf you are really interested in EMTDC, please read the manual carefully, and you should also read EMTP theory book and take power system analysis courses in university.
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7 F/ V% {; Z8 U" O' \2 _0 b0 E/ n- NThose programming tip/detail is no that important, but sometime fun...
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Help the above helps. |
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