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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
/ B8 A2 @3 F# C3 z' D" ^& V+ H! T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 ...
8 V9 c5 \9 |& L" H/ Y5 `1 @shanby 发表于 2014-12-21 21:06
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; e* k) @& y- L9 r' g% B 查看如下帮助文档：Assumptions9 i# R" I+ `9 S8 I1 Q! _8 V- q
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.Limitations
8 Z' l" d9 o0 N F+ t+ tWhen 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：
; i7 J: b( E3 ? n! D1.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；3 R0 i) R* i: }; A1 O1 c
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）
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试错结论：
4 q& X% E M- P' Q5 b0 ^* f& `+ a1.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）3 m* B: T, m3 k' Q
2.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。+ t# l" f( w2 o5 m1 v* q5 }
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）。" K- D( P# v# l; T+ v) O
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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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# g* G7 N7 }3 |1 t# @疑问：' |. y. L/ `% W' ]
1.如何解释模型搭建、报错和试错结论？
) I1 X; A E, Y" R4 V; e9 R, a8 Q2.Simulink仿真的逻辑？
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发表于 2014-12-21 21:06:44
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