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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 Y w* e4 B( l) sThere is a ramping time you can choose. The ramping pattern can be linear, exponential or other...
! e" o6 w4 l& u& H9 Y* w% x& `for instance, linear...
! G5 p, l8 H0 |2 F! M8 o+ v0 J# D1 PVa=Vm*t*sinwt
& O2 M" s* @" I) J7 Q5 r) N8 S( Q! }Vb=Vm*t*sin(wt-120)2 l" h f c y5 W9 D* ^2 j, ]& I
Va=Vm*t*sin(wt+120). H9 }1 z, e- n, o% ~4 I2 b
: g7 L' `7 V0 G: c& H% mwhen t=0, va=0, vb=0 and Vc=0 np problem.
. ~9 s+ j+ H+ jt can be normalized so that the magnitude can be ramp to the Vm in certain time, then stays there.6 H& a! _6 Q5 j v
B4 S% N; U: h( K5 ?! R- @There is no problem to implement this.- \2 V1 d/ u) K% H
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Anyway, focusing on such small detail won't help you understand the simulation.9 o( M- P4 B5 i& }
& {1 b6 n8 N; k o3 d& KIf 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.) G9 M" F% V& h4 u @8 H
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Those programming tip/detail is no that important, but sometime fun...$ M: G% [0 g) j' q& ]3 o0 H
8 d4 Z/ ^& c; m% U# @2 U8 `Help the above helps. |
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