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发表于 2014-12-31 11:34:51
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本帖最后由 shanby 于 2014-12-31 11:45 编辑
I6 [. g) M1 K0 E/ d$ m接线情况:模拟2台150MW,35kV的发电机分别接入2台分裂升压变压器,再由220kV接入大电网。在35kV母线接 ...
- _! x; ?: D3 U4 S( Mshanby 发表于 2014-12-21 21:06 ( B7 m7 \3 b4 E1 A! N' w
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) p; B, @; @# J: k/ @4 J" S' s 查看如下帮助文档:Assumptions, Q" m/ T* X: C* [8 o' i3 k- k
The electrical system of the Simplified Synchronous Machineblock consists solely of a voltage source behind a synchronous reactanceand resistance. All the other self- and magnetizing inductances ofthe armature, field, and damping windings are neglected. The effectof damper windings is approximated by the damping factor Kd. The threevoltage sources and RL impedance branches are Y-connected (three wiresor four wires). The load might or might not be balanced.Limitations8 z& @ i3 @5 Z8 m2 F0 N
When you use Simplified Synchronous Machine blocks in discretesystems, you might have to use a small parasitic resistive load, connectedat the machine terminals, in order to avoid numerical oscillations.Large sample times require larger loads. The minimum resistive loadis proportional to the sample time. As a rule of thumb, remember thatwith a 25 μs time step on a 60 Hz system, the minimum load isapproximately 2.5% of the machine nominal power. For example, a 200MVA simplified synchronous machine in a power system discretized witha 50 μs sample time requires approximately 5% of resistive loador 10 MW. If the sample time is reduced to 20 μs, a resistive loadof 4 MW should be sufficient.
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得出:
" T: g6 J! {9 Y& X; e. }& A1.简单同步发电机模型采用带电阻和电抗、独立电压源,三相Y连接的电气模型;- e. Q8 S, e' ]6 J2 P1 f' [
2.使用边界限制:如果是采用离散系统仿真,则需要在发电机端子连接寄生小电阻,其阻值或功率与离散系统的采样时间成比例(举例有计算实例)+ v! L& b6 `% ~9 M, ]
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试错结论:
. W- t1 i+ M0 Q1.错误提示说简单同步发电机是电流源,需要并联高值电阻。这与帮助文档电压源的说法不一致(尽管电压源和电流源和也互相变换)
7 {; U8 ], r$ O% D2.将powergui模块参数设置为continous,仿真报错与设置为discrete的报错信息一样。
. ^+ ~" W3 ` c$ F i3.将powergui模块参数设置为discrete, 按错误提示边栏电阻,则仿真不报错(虽然结果不是预期)。
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ShortCurrentFor300MW2.rar
(9.71 KB, 下载次数: 1)
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电压波形
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疑问:8 ]# s! a( I! C6 f3 Y% ?
1.如何解释模型搭建、报错和试错结论?; e' I; e4 e9 l6 T2 D
2.Simulink仿真的逻辑?- B4 |5 q" c s; f* P5 z2 y6 B
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