An efficient,simplified multiple-coupled circuit model of the induction motor aimed to simulate different types of stator faults

This paper proposes an original simplified model aimed to simulate, an easy way, inter turns short circuit fault, phase to phase fault and phase to ground fault. In this model, the stator is considered as six magnetically coupled windings and the rotor as three not magnetically coupled R–L circuits. The paper also presents the star- and delta-connected stator configurations of the simplified model. However, the proposed simplified model is suitable only for steady-state operation. The performance of the simplified model is first verified by a comparison between the simulated current of the multiple-coupled model and the simplified model. Then, since the stator faults have an impact on the symmetrical components of the stator current, this paper uses these components to validate the behavior of the simplified model by simulation and experimentally using a 1.1 kW motor. In addition, simulated results of the simplified model for a 110 kW motor are presented in order to generalize the use of the proposed model to larger motors.     

Measurement involving human perception and interpretation

The measurement of features related to human perception and interpretation is discussed. After a brief review of the historical framework, the state of the art is presented on the basis of the authors’ experience in the field and their participation in related European projects, with development of experiments, and co-ordination activities. Future research needs and challenges are then addressed.     

Modelling of light extinction by soot particles

A simplified model for the prediction of light extinction through combustion generated smoke is presented. The model builds upon existing theory and available experimental data to account for the principal factors that influence light extinction in participating media, including wavelength, primary particle size distribution and morphological structure of particle aggregation as well as multiple scattering among particles within a particle aggregation. Good agreement is demonstrated between the model predictions and experimental data in the visible and IR ranges. The model illustrates that as the mean particle size increases, the integral optical property of a soot cloud approaches that of monodisperse particles. It is postulated in the current study that the number of particles participating in multiple scattering is around 20 regardless of the real size of particle aggregation.     

Two‐dimensional guidelines for measurement system indices

In this paper, we review two common measurement system indices and a common process capability index. With some simple plots, it will be shown that the traditional guidelines for these measurement system indices can often misdirect improvement efforts. By taking advantage of the relationship between the measurement system indices and the process capability index, two‐dimensional guidelines that can be used as an alternative to the traditional guidelines are developed. These two‐dimensional guidelines are intended to help address adequacy of the measurement system and better direct improvement efforts to where there will be the most benefit. Copyright © 2010 John Wiley & Sons, Ltd.     

TK250-14/430同步电动机特殊故障判断检修

通过分析TK250-14/1430I同步电动机转子短路环连接处易松动问题的产生原因,找出了解决该问题的具体办法,具有一定的参考价值。     

龙耀路越江隧道通风系统设计

根据龙耀路越江隧道分期实施投入运营的情况,介绍了隧道通风系统设计。接着介绍了通风设备配置情况。最后分析了隧道峒口内环境,经计算,CO浓度均满足设计标准。     

退耕还林对志丹水文站水沙量影响浅析

通过对志丹水文站径流量、输沙量的分析,探讨了退耕还林对志丹水文站水沙量的影响,并对志丹县退耕还林的可持续性等方面提出建立生态补偿机制等,同时得到了沙量、水量变化规律。     

A novel adaptive flicker measurement technique

An adaptive measurement method is presented for the estimation of interharmonic components causing light flicker. The method provides an alternative technique for the estimation of sinusoidal components of unknown frequency, where well-known methods of processing of stationary signals such as the DFT-based techniques may fail. The proposed technique is based on a recently developed sinusoid-tracking algorithm that is capable of tracking time-variations of the parameters of a nonstationary signal such as its frequency and amplitude. The preliminary stages of demodulation and bandpass filtering combined with dynamic adjustment of the parameters of the sinusoid-tracking algorithm allow for effective estimation of the components that may cause light flicker. The structure of the proposed flicker measurement technique is composed of two parallel branches, each finding the amplitude and frequency of an interharmonic component. Presented computer simulations demonstrate its performance while laboratory experiments verify its in situ functionality. Given the low complexity of the proposed technique, it is well-suited for real-time applications.     

晶闸管控制的单相–三相变换器

提出一种单相电源供电时适用于异步电机传动的单相–三相变换器。由于仅采用7个晶闸管和1个移相电容,该变换装置具有造价低、结构简单的特点。分析该变换器的工作原理及开关过程,并提出一种基于开环变压变频(variable voltage variable frequency,VVVF)和变压恒频(variable voltage constant frequency,VVCF)控制的单相–三相离散跳频控制策略,用于电机的起动和稳态运行控制,一方面保证了电机在低频阶段足够大的起动力矩,另一方面可使电机稳步起动到额定转速。仿真和实验结果表明了该控制策略的有效性以及系统方案的可行性。     

基于自适应邻域算法的智能照明控制系统

本研究提出一种新型的智能照明控制系统,该系统基于一种新型自适应算法ANA／CC（基于相关性系数的自适应邻域算法）,并且运用最新提出的可视光通信技术在照明设备和照度传感器之间建立直接的通信,从而为特定的地点提供所需要的照度。在整个系统建立的过程中,我们还特地为该系统建立控制模型,经过实验和仿真发现,该模型可以在短时间内令测试地点的照度达到目标值。