Control method of three-level neutral-point-clamped inverter based on voltage vector diagram partition

A new modulation approach was presented for the control of neutral-point (NP) voltage variation in the three-level NP-clamped voltage source inverter, and the average NP current model was established based on vector diagram partition. Thus, theory base was built for balancing control of NP potential. Theoretical analysis and experimental results indicate that the proposed method for NP balancing control vector synthesizing concept based can make the average NP current zero, and do not influence NP potential within every sample period. The effectiveness of proposed research approach was verified by simulative and experimental results.     

数字地面模型的研究及实现

本文在对数字地面模型介绍的基础上，分别从狄洛尼三角网的特性、TIN模型算法、三角形定位、影响域的确定及数据结构分析等几个方面对数字地面模型进行研讨，对于类似一体化设计中对数模的要求问题，有借鉴作用。     

杭甬铁路客运专线选线研究

杭甬铁路客运专线地处长三角南翼,经济较为发达,城镇化水平较高。在铁路选线时,除了正常的选线手段外,针对杭甬通道的特殊情况,如何满足地方规划、节省工程投资、充分利用既有的通道资源,减少对地方的影响,集约和节约用地作了详尽的研究,线路走向满足了地方的需要,可为今后经济较发达、城镇化水平较高的地区选线提供借鉴意义。