Performance analysis of individual blade pitch control of offshore wind turbines on two floating platforms

Individual blade pitch state space (IBP SS) control and disturbance accommodating control (DAC) that reject wind speed perturbations are applied on a 5 MW wind turbine mounted on the barge and tension leg floating platforms for performance comparison in above rated wind speed region. The DAC used in this study is simply an IBP SS controller with a wind speed disturbance rejection component. For each controller implemented onshore and on the floating platforms, 60 10-min simulations with a variety of wind and wave conditions, where applicable, are carried out in accordance with the IEC-61400-3 standard design load case 1.2 for fatigue load testing. Results show that even with large tower load reductions by the IBP SS controller on the barge platform, these loads are still at least two and up to five times more than that for an onshore wind turbine. DAC on the barge platform has little impact on further improving the performance of the IBP SS controller. DAC on the tension leg platform manages to achieve loads comparable to that of the onshore system. Power and rotor speed regulation are improved and tower side-side load is reduced. Only the tower fore-aft load is 24% higher than the onshore wind turbine.     

我省中小企业计量工作有待加强

我省电子产品生产企业众多,又以中小企业占绝大多数.不少企业对<中华人民共和国计量法>不了解,无计量法制观念.因此要对我省中小企业加强计量监督管理.     

浅谈北方非织造布发展战略

简述了国内非织造发展概况,分析和探讨了北方地区非织造布工业存在的差距和产品发展前景,并提出了北方企业发展的战略和对策。     

The Digital Age of Mobile Cellular Network in Germany and China ：Policies,Technologies and Markets （Part Ⅰ）

The German Postal Reform I in 1989 introduced competition in the mobile cellular market. German cellular operators, DeTeMobil, Mannesmann, E-Plus and VIAG Interkom, built D1-, D2-, E1-and E2-Netze based on GSM standards made in Europe. China Unicom was created in 1994 and China Telecom was separated from MPT in 1995. China Telecom and China Unicom competed in a duopoly from the mid-1990s onwards and the cellular services provided by them also rely on GSM standards. China Telecom additionally deployed XLT technology (PHS) from the late 1990s onwards. While DeTeMobil and Mannesmann conquered approximately 80%-90% of the market throughout the 1990s and were the two dominant market players in Germany, China’s cellular market was mainly controlled by China Mobile. In Germany, prices related to cellular technology continued the downwards trend as a major result of the process of deregulation, liberalisation and competition. In China, price wars had led to significant price reductions in the cellular market. Although network operators in both countries strived to deliver differentiated cellular services, the two national markets in the 1990s were visibly shaped by product homogeneity.     

The Digital Age of Mobile Cellular Network in Germany and China：Policies,Technologies and Markets （Part Ⅱ）

The German Postal Reform I in 1989 introduced competition in the mobile cellular market. German cellular operators, DeTeMobil, Mannesmann, E-Plus and VIAG Interkom, built D1-, D2-, E1-and E2-Netze based on GSM standards made in Europe. China Unicom was created in 1994 and China Telecom was separated from MPT in 1995. China Telecom and China Unicom competed in a duopoly from the mid-1990s onwards and the cellular services provided by them also rely on GSM standards. China Telecom additionally deployed XLT technology (PHS) from the late 1990s onwards. While DeTeMobil and Mannesmann conquered approximately 80%-90% of the market throughout the 1990s and were the two dominant market players in Germany, China's cellular market was mainly controlled by China Mobile. In Germany, prices related to cellular technology continued the downwards trend as a major result of the process of deregulation, liberalisation and competition. In China, price wars had led to significant price reductions in the cellular market. Although network operators in both countries strived to deliver differentiated cellular services, the two national markets in the 1990s were visibly shaped by product homogeneity.     

3C认证中需要补充的质量管理体系文件

阐述了在3C认证过程中，质量管理体系文件的补充如何既能满足ISO9000标准又能涵盖工厂质量保证能力要求。     

中国通信产业政策展望

我国通信产业政策主要涵盖总量调节、总构管理、产业发展战略与规划、资源配置等方面的内容,其旷日持久是促进产业持续增长,保证通信产业协调发展,实现资源优化配置。随着通信产业的发展,实现资源优化配置。随着通信产业的发展,通信产业政策在技术、革命、市场融合、产业发展道路、政府的经济责任等方面面临机遇和挑战,适应通信产业未来形势变化,以体制改革为重点的产业政策相关调整应在情理之中。     

2005年中国电信运营市场发展现状与展望

2005年是中国电信业的“转型年”．国内电信运营商依赖投资拉动增长速度减缓的趋势得以深化。国内电信运营商的投资更加趋于理性。通过总结2005年田内电信运营市场态势、各运管商发展策略、行业热点及未来展望四个方面阐述国内电信运营市场的发展状况。     

带内数模混叠同播中的OFDM对FM的干扰分析

OFDM与FM带内数模混叠同播是中国发展数字调频的一项重要候选技术,评估OFDM对FM解调的影响是选择OFDM与发射功率比的重要参考依据.在给出了三种常见调频解调算法公式的基础上,通过仿真评估了OFDM对FM解调失真度和信噪比的影响.仿真结果表明,在OFDM与FM发射功率比高于-11 dB时发生明显的捕获效应.     

增强自主创新能力 支撑企业战略转型

本文首先介绍了中国电信集团和各省公司在技术创新方面所做的工作及目前取得的初步进展和成绩.然后进一步分析了中国电信技术创新面临的形势和要求,最后提出了中国电信技术创新的目标和战略.