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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 $ A4 I+ K' g: R' y5 w( R) 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 .../ N" `" |* I& y+ P, A
shanby 发表于 2014-12-21 21:06
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查看如下帮助文档:Assumptions
( `1 e! y9 J7 L, tThe 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.Limitations
3 g' D9 Y f: T/ i. @4 XWhen 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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1.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;& U! l3 H; V$ W4 U; ^: E' U
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)0 N+ b+ f1 g5 b& G
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试错结论:
2 b' D( x ^. e3 ]) |1.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)
8 O" m( y3 L6 W& J0 O) [! h2.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。" e' t7 U" E# z" W* x8 p, r) h; P4 m* a
3.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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: h4 t; `/ A/ c! w疑问:
) J, F) J- w3 x7 n4 \1.如何解释模型搭建、报错和试错结论?
3 K8 T7 E: d$ N2.Simulink仿真的逻辑?
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