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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 & r$ Q) f! L. U
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 ...
' ^1 N9 @3 A2 c! Sshanby 发表于 2014-12-21 21:06
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0 `, T' Q& E$ V3 |: U4 U5 x; i% X0 f1 H 查看如下帮助文档:Assumptions
/ U- Q* o& b. j7 G. D( D" f: U H& zThe 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) c3 W" N& h: I* l8 f; U# H0 n0 _
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:
5 w2 ^- T, Y# v% s& b1.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;7 Z$ o3 s0 i' L9 ^( [* Q$ K' y
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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. R K) F6 r, t% Q0 B试错结论:
: Y0 ~- T6 M) i! ?- U) O: E6 O8 z1.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)
9 f" X: I$ Z4 I2.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* b' o4 k# |3 }, ?) Z8 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:
# {# M0 J& \# X/ {) h1.如何解释模型搭建、报错和试错结论?2 V8 N, t$ A$ @ r( U3 n
2.Simulink仿真的逻辑?/ _7 h0 D, x Z- ?% }" A
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