问题 问答题 简答题

何谓稳定性问题、静态稳定暂态稳定功角稳定

答案

参考答案:

稳定性问题是指电力系统在运行时受到微小的或大的扰动之后,能否继续保护系统中同步电机同步运行的问题称为电力系统稳定性问题。静态稳定是指电力系统在运行中受到微小扰动后,独立地恢复到它原来的运行状态的能力叫静态稳定;暂态稳定是指电力系统受到较大的扰动后各发电机是否能继续保持同步运行的问题;功角稳定是指系统中各发电机之间的相对功角失去稳定性的现象。

单项选择题

It’s easy to get the sense these days that you’ve stumbled into a party with some powerful drug that dramatically alters identity. The faces are familiar, but the words coming out of them aren’t. Something has happened to a lot of people you used to think you knew. They’ve changed into something like their own opposite.

There’s Bill Gates, who these days is spending less time earning money than giving it away--and pulling other billionaires into the deep end of global philanthropy(慈善事业) with him. There’s historian Francis Fukuyama, leading a whole gang of disaffected fellow travelers away from neoconservatism. To flip-flopis human. It can still sometimes be a political liability, evidence of a flaky disposition or rank opportunism. But there are circumstances in which not to reverse course seems almost pathological(病态的). He’s a model of consistency, Stephen Colbert said last year of George W. Bush:" He believes the same thing Wednesday that he believed on Monday -- no matter what happened on Tuesday."

Over the past three years, I found people who had pulled a big U-turn in their lives. Often the insight came in a forehead-smiting moment in the middle of the night: I’ve got it all wrong.

It looked at first like a sprinkling of outliers beyond the curve of normal human experience. But when you stepped back, a pattern emerged. What these personal turns had in common was the apprehension that we’re all connected. Everything leans on something, is both dependent and depended on.

"The difference between you and me," a visiting Chinese student told University of Michigan psychologist Richard Nisbett not long ago," is that I think the world is a circle, and you think it’s a line." The remark prompted the professor to write a book, The Geography of Thought, about the differences between the Western and the Asian mind.

To Western thinking, the world is linear; you can chop it up and analyze it, and we can all work on our little part of the project independently until it’s solved. The classically Eastern mind, according to Nisbett, sees things differently: the world isn’t a length of rope but a vast, closed chain, incomprehensibly complex and ever changing. When you look at life from this second perspective, some unlikely connections reveal themselves.

I realized this was what almost all the U-turns had in common: people had swung around to face East. They had stopped thinking in a line and started thinking in a circle. Morality was looking less like a set of rules and more like a story, one in which they were part of an ensemble cast, no longer the star.

Which of the following is the best title for this text()

A. The Age of U-Turns

B.Western and Eastern Cultural Differences

C. A Circle World

D. The Importance of Change

单项选择题