Question

毕业论文摘要翻译软件

三相异步电机是现代化工业的基本动力来源，其在额定电压下空载直接启动时，电流达到额定值的5~8倍，甚至更高，带载直接启动电流更大，大电流会拉低电网电压也会损坏电机。为了克服起动电流大的弊端我们通常采用降压起动方式起动，目前应用最为广泛和成熟的可控硅调压型软起动器这一控制装置，其转矩大小跟电压平方成正比，所以起动转矩随电压的降低而呈2次方降低，电流却降的不多，且起动转矩和起动电流非线性，这主要是由于相控调压时谐波含量显著增加、功率因数下降所引起。同时，起动转矩小的特点也限制了电机的应用范围，使得传统的软起动器只能应用于空载或轻载起动场合。但是，在实际电动机应用领域中往往要求控制装置能够根据负载情况灵活的选择起动方式，这就需要研究如何在减小起动电流时提高其起动转矩。
针对目前软起动器存在着起动电流大、起动转矩低的缺点，本文提出一种以变频调速为基础理论，以电压空间矢量原理为实现方法的新型软起动控制策略，并设计三相电源缺相相序检测程序、空间电压矢量控制程序、红外遥控参数设置与液晶界面显示程序，通过多中断协调设计在空间电压矢量的软起动器硬件系统上形成完备软件系统，实现基于空间电压矢量的多级变频软启动。将该软起动器与传统的调压软起动效果进行了比较，实验结果表明：基于正弦波电压空间矢量的软起动器可起动带有一定负载或较大惯性负载的电动机，而且电流保持在较小的值。

Answer 1

Abstract: in many practical problems, the training data is different, usually some training data may be more important than other data. Each group of training data depict different function is usually through each training data gives an incredible weights, based on the fuzzy data, this paper has deduced the classic again in the regression method, and the relative cases of fuzzy regression method, and analyzed their statistical properties. In fuzzy statistic analysis of the traditional methods are incredibly weight by setting the fuzzy membership functions, such as to determine the time sequence function etc. Considering the DEA method in the analysis of the relative effectiveness evaluation decision unit has not underestimate the superiority of the DEA method, then we introduce fuzzy statistic analysis, and usually use the fuzzy membership functions of the incredible weight determined comparing method, fuzzy statistic analysis method in DEA model is superior. Keywords: DEA analysis method, Least-squares regression analysis, Fuzzy statistic,