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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.
3 ~* h0 V7 P) l3 K1 Y, y& yThere is a ramping time you can choose. The ramping pattern can be linear, exponential or other...6 K# v( g% O" n% I+ b
for instance, linear...
0 I5 k) v& V+ D q' m3 F$ m0 X5 Q4 lVa=Vm*t*sinwt2 ^) n. e- H) A/ F% p
Vb=Vm*t*sin(wt-120)3 z3 |0 I. f' b; s
Va=Vm*t*sin(wt+120)$ V/ K9 T. |) V- I# q( ^ Q
! q' N: [/ L: q% uwhen t=0, va=0, vb=0 and Vc=0 np problem.
4 ^ u5 J; e+ ?. N; {t can be normalized so that the magnitude can be ramp to the Vm in certain time, then stays there.9 C7 R4 g% H( O
; g* m, b" j" VThere is no problem to implement this., _+ T& L( L0 u+ F2 B1 M; [8 u. r
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Anyway, focusing on such small detail won't help you understand the simulation.: e6 B1 _4 r$ B5 K: @: k
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If 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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5 f$ R6 \2 N* X# _$ h! s& FThose programming tip/detail is no that important, but sometime fun...$ _) J3 l( j g( J$ q" @
. j) ] h1 S2 Z8 l. `2 r6 D+ H- M& sHelp the above helps. |
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