ASSESSMENT OF AN ELECTRO MECHANICAL DIFFERENTIAL GEAR PROVIDING VARIABLE SPEED TO INDUSTRIAL APPLICATIONS

当前,标准工业应用对于整体传动系统效率的要求日益提高,如压缩机、鼓风机、风扇及水泵。现有的系统如VFD或液压变速控制系统不能满足能源成本的需求。几年前一个创新性的变速系统EMDS(机电差速系统)出现在市场上,在总效率和初始成本上显示出巨大的潜力。该系统由一个主驱动(直接连接电网)、一个包含行星齿轮级的齿轮箱和一个伺服变频控制驱动组成。伺服驱动(最大为系统总功率的20%)通过主驱动的恒定速度来控制齿轮箱输出速度。此外这一设置使得电力元件最少化同时在整个传动当中占用空间小。研究表明,该系统可应用于最高至15MW和15 000r/min速度的变速应用上。长期运行将证明,该方案是否能安全满足工业的高标准和需求。作者对比了EMDS和其他变速系统的技术优势,并分析了EMDS的技术原理并包括详细的效率对比。此外还给出了实际应用证明案例。

Nowadays there is an increasing pressure on industry to increase the efficiency of the whole drive train for standard industrial applications like compressors, blowers, fans and pumps.One major key to ensure this high energy savings is the regulation of speed and power according to the actual demand of the driven machine.Common systems like the VFD （variable frequency converter） or hydraulic variable speed control systems meet the requirements unsatisfactory with respect to energy costs. Since a couple of years a new innovative variable speed system the EMDS （electro-mechanical differential system） is on the market showing high potential in terms of total efficiency and initial costs. This system consists of a main drive （directly connected to the grid）, a gearbox incl. a planetary gear stage and a frequency controlled servo drive. The servo drive （max. 20% of the total system power） controls the output speed of the gearbox by a constant speed of the main drive. Furthermore, this set-up leads to a minimum amount of electrical components and a small overall footprint of the complete drive train. Investigations have demonstrated that this system is applicable for variable speed applications up to 15MW power and 15.000rpm speed. Long-term operation will prove, if this approach does satisfy the industry＇ s high standards and needs. The Author compared the technical advantages between EMDS and other variable speed systems and analyzed the technical principleof EMDS including a detailed efficiency comparison. Additionally, a case of practical application is demonstrated.