Study on Eddy Current Problem in High Speed Operation of Hsst-type Maglev System

The digital information revolution has brought profound changes in our society and our lives. The many advantages of digital information have also generated new challenges and new opportunities for innovation. Broadband internet and wireless network environments which have made considerable progress in recent years offer many opportunities to deliver and to exchange information. The fair uses of digital contents as well as the efficient delivery of digital contents to end users are important topics. This thesis discusses issues regarding copyright protection systems using fingerprinting schemes for preventing an illegal redistribution of digital contents. Study on Eddy Current Problem in High Speed Operation of HSST-type Maglev System |Compared with the conventional wheel-on-rail trains, the Maglev (magnetically levitated) systems have the merits of low environmental pollution, low maintenance cost, and high-speed performance. According to levitation methods, MAGLEV transport systems can be classified into two groups: Electromagnetic suspension (EMS) and Electrodynamic suspension (EDS). Furthermore there are two kinds of EMS systems according to speeds or applications. One is the high-speed EMS Maglev system like the Transrapid developed in Germany, which uses linear synchronous motors (LSMs) for propulsion. The other is the low-speed EMS Maglev system like HSST (High Speed Surface Transport) developed in Japan, which uses linear induction motors (LIMs) for propulsion. Maglev systems using electromagnetic suspension (EMS) and linear induction motor (LIM) technologies are usually used for low-speed applications. For example, a commercial line of the HSST system is now under construction near Nagoya, Japan, and will be operated at speeds up to 100 km/h in 2005. Although it is believed that an EMS-LIM system could be operated up to 200 km/h, the influence of eddy current induced in the steel rails would become more serious. Non-laminated steel rails are normally used in such systems and consequently eddy current is easily induced by moving magnets. The induced eddy current reduces levitation force and generates drag force against propulsion force by LIMs. Therefore in order to make the EMS-LIM system operate at high speeds about 200 km/h, it is necessary to calculate the eddy current and investigate how it influences the levitation and propulsion forces. This study engaged in calculation of eddy current generated in the steel rails of an EMS-LIM system moving at high speeds up to 200 km/h and investigation on influence of the eddy current on electromagnetic force characteristics. In this calculation, the HSST-100L system was employed as the calculation …