基于内模原理的三相电压源型逆变电源的波形控制技术

恒频恒压(CVCF)交流逆变电源一般用在比较特殊而重要的场合，其输出电压波形质量是衡量其性能的重要方面。该文分析了三相逆变电源输出电压波形控制基于旋转坐标系扰动内模原理方案的可行性，提出了旋转坐标系下基波扰动瞬时值控制内模与谐波扰动重复控制内模结合的方案。仿真和实验验证了该方案可以保证系统有较快的动态响应，稳压精度高，输出电压谐波畸变率小。     

计及铁心动态磁化特性的三相变压器励磁涌流的仿真研究

介绍了计及铁心饱和，磁滞，局部磁滞和原始剩磁影响的三相三柱式变压器磁励涌流的仿真数学模型及仿真计算程序，对三相三柱式变压器空载合闸时的励磁涌流作了仿真计算，并对其结果进行分析。     

三相异步电动机起动方式的分析与选择

通过分析三相异步电动机各种起动方式的电压、电流、转矩的波形和特性,合理选择合适的起动方式。     

三相逆变器不平衡抑制研究

三相逆变器的一个重要性能是输出电压的对称性，输出电压不对称主要由不平衡负载引起，文中基于对称分量法和叠加原理分析了输出基波电压对称性畸变机理，指出了输出电压正、负、零序分量不同的补偿特性，表明输出电压对称性控制不仅与控制器性能有关，还取决于逆变器电路结构的固有特性，并提出了改善逆变器输出对称性的方法。仿真和基于DSP控制的35kW逆变器样机实验均验证了理论分析结论。     

改进模拟退火算法在三相异步电动机优化设计中的应用

为了更好地将模拟退火算法应用于三相异步电动机优化设计中,本文分析了模拟退火算法的优点和局限性,针对其搜索过程慢的缺点,提出了改进模拟退火算法的思路和具体实现方法,并通过两个经典数学函数检验了新算法的性能.在此基础上,将改进模拟退火算法应用于三相异步电动机优化设计中,分别以有效材料成本最小和效率最高为目标进行了优化设计.结果表明,在不改变电动机的结构设计和制造工艺的情况下,基于改进模拟退火算法的优化设计能显著减小材料成本和提高电动机效率,具有工程实用价值.     

Comparisons of α-amylase inhibitors from seeds of common bean mutants extracted through three phase partitioning

This study compared the inhibitory activity of α-amylase inhibitor (αAI) extracted from common bean (Phaseolus vulgaris L.) variety Hwachia, its nine mutants and two introduced varieties by using three-phase partitioning (TPP). A commercially prepared Phase 2 was also used to serve as a comparative reference. The optimal purification parameters for TPP were 30% saturation ammonium sulphate and pH 5.25. Considerable variations were detected in αAI content, total inhibitory activity and specific inhibitory activity of αAI purified from different common beans. Mutant SA-05 had the αAI inhibitory activity of 6267 units g⁻¹ dry seed weight, which was higher than Hwachia (5062 units g⁻¹ dry seed weight) and Phase 2 (3200 units g⁻¹ dry weight). Moreover, it had an extremely lower IC₅₀ (0.40 μg) than Phase 2 (10.22 μg). Thus, the mutant SA-05 may be used as raw material in commercial preparation of αAI extracts for controlling appetite and energy intake.     

500kV壳式三相并联电抗器开发设计

介绍了500kV壳式三相并联电抗器的设计开发情况,其中包括壳式并联电抗器的基本设计、振动计算、电场计算分析和结构上的抗震措施等内容。     

电动机与可调液力变矩器的合理匹配

在液力传动机械中,将动力源与液力变矩器进行正确而合理的匹配,是使其获得良好的动力性、加速性和经济性的关键。以往见之较多的是柴油机与普通不可调液变矩器的匹配,而本文涉及的是鼠笼式三相异步电动机与导轮叶片可旋转的可调液力变矩器的匹配,有其新颖和独特之处。文章论述了电动机与可调液力变矩器的共同工作的特点、它们的匹配方法、匹配中的函数关系以及最佳匹配的获得等。这些问题的研究与探讨,对于促进我国液力传动的新发展,无疑是大有裨益的。     

Study of propagation phenomena in three-phase form wound machines operating at medium and high frequency

A three-phase model of asynchronous machines operating at medium or high frequencies is presented. It can be used to study the propagation of surge waves along the stator windings of induction form wound machines.The model is derived from an analogy with a three-phase transmission line. The use of time-space Clarke vectors allows the introduction of mutual coupling between phases. The analytical expressions for voltage waves are derived by means of the Laplace approach to the solution of hyperbolic partial differential equations.Some applicative examples confirm the model validity and can underline some aspects of the project of three-phase windings.     

逆变器短路控制式串级调速系统在发电厂排煤粉机90kW绕线式异步电动机上的应用

本文介绍了逆变器短路控制式串级调速系统在本钢发电厂排煤粉机00kW绕线式异步电机上的应用,文中介绍了该串调系统的工作原理,实际构成,工业实验结果及体会。