本帖最后由 yizhangsjtu 于 2009-11-16 12:00 编辑
回复 1# bcpan118
Sorry I cannot write Chinese in this computer. But I would like to comment on the question you raised, as this topic might confuse many people.
The question itself on UHVDC is kind of new, but the property of voltage stability of HVDC won't have any change if it is UHV. Choosing such topic seems attract eyeball but in fact causes extra confuse for students. Atucally HVDC AC has more special problem. While in UHVDC, the hard things are main on insulation and equipment. There is no speical on anything about voltage stability.
Let me be clear here.
1.The voltage stabilty (often means steady state ability) of HVDC system should be understood in 2 different aspects.
(1) One is the power stability. The HVDC has no angle stabilty problem. The so call stability problem of HVDC is a control stability, in which the maximum available power (MAP) transfer is started.
(2) The other is seen from AC side. DC is a nonlinear load from AC side, which has its special impact on PV curve of AC side.
Those two problems are different, and they have different Pmax and Qmax. Reach either of them will lead to instability.
2. Transient voltage stability
There is concern from AC side of convert bus transient voltage. Those concerns include over voltage of DC, AC fault, DC block, and AC/DC voltage recovery during and after fault. Different reactive support methods are studied based on EMT type simulation. The reason to use EMT type simulation is the mechanism of the problem is not clear, so there is no good simplified model available for use. Therefore, choosing detail model is a MUST for the current situation.
As far as I know, there is no transient voltage stability thing in DC side.
I would like to comment here that the most important thing here is understanding the problem rather than choosing a software and run. As you may understand, the DC is kind of special thing so it is not very accurate modeled in most of the software. That is why people like to choose PSCAD, since its model is detail so the usersdon't need many knowledge before use it. For those simple model program, as good as TSAT or VSAT, you should understand DC first then you can wisely use it get the result you expect. It is very easy to go into "garbage in and garbage out" here. Very careful prepare work is desired before you start to analyse the DC stability problem.
The hard thing is the DC is not well taught in any text book. As someone mentioned before, Taylor's book hascharpter on this issue. This charpter is all correct and well written. However, it has same issue as above. The readers need good back ground to understand it. It is too brief and contains too much things.
Spent 45 minutes, Hope版主加精华, heheh...
我觉得PSS/E好一些
yizhangsjtu介绍的很清楚啊，看来要搞HVDC的研究，深厚的专业背景是必须的，否则只能是了解。好像我们教授也说过，在高压输电领域任何东西只要用在直流上，绝缘性质和电流电压特性都变掉了，所以对高压元件的研究多于系统。
帮你顶一下，不是很清楚！！！！
I agree my comments is not clear enough. That is a long story, which I cannot explain in a small article. Actually there is no book can tell you the HVDC very clear. That's why not many people know that. I am sorry for this.
除理论方面的电力电子应用也非常广泛
pscad是研究电磁暂态仿真的，稳定方面的用的很少。这个看来得自己搭模型才可以，和楼主一起探讨
直流电压的研究，主要侧重于换流母线上的电压稳定性。换流母线电压的稳定直接决定了直流系统是否能稳定运行。PSSE不错
好强大啊我本来也有这方面的打算，但听版主这么一说似乎还这有点悬乎在里面的
应该之前的软件都能用的
