Energy storage and conversion:Driving human development

Energy scarcity and environmental pollution are worldwide issues which plague human development.According to projections for economic development and population growth,global energy demand is anticipated to double by 2050 and triple by2100.Better energy storage and conversion are glorious but arduous missions in the 21st century.Although the fossil

Four-quadrant Force Control with Minimal Ripple for Linear Switched Reluctance Machines

Linear switch reluctance machine(LSRM)has been tried to act as an alternative generator for direct drive linear wave energy converter(WEC).Many researchers have proposed new topologies of LSRM to improve the power density,efficiency and reliability.However,the control methods for LSRM applied in direct drive WEC have been paid little attention,especially control methods considering the wave energy generator operating characteristics.In this paper,according to the generator control requirements of the direct drive WEC,force control algorithm for LSRM operating in four quadrants without a speed closed loop is put forward.The force ripple of LSRM is suppressed using force sharing function method.The four-quadrant control is easy to realize requiring only phase currents information.Simulation results validate the proposed method and indicate that LSRM is able to be used as the generator for direct drive WEC.

SINAMICS—the high efficiency drive technology for rolling mills

In the Metals Industry,interruption-free processes to produce high-quality end products are a prerequisite. The main drives together with the mill stands play a key role in the success of rolling mills.The crucial demands placed on the drive system are:high-dynamic performance of drive and its control system,ability to handle the process related overloads,smooth running,high availability,high efficiency,easy serviceability and ability to integrate seamlessly with the automation systems.With numerous reference installations and many years of experience Siemens VAI has the wider expertise and the portfolio to provide the right drive for every application. This paper examines the latest innovation,SINAMICS drive technology,for both new drive applications as well as for modernizing the existing drives in rolling mill applications like hot strips mills,plate mills,cold rolling mills,and long rolling mills.

Drive for Nuclear Energy

New Delhi warms to the United States in a bid to acquire nuclear technologies for energy independence and strategic influence on July 21, U.S. Secretary of State Hillary Clinton completed her five-day trip to India. The two sides reached several agree-ments during the visit. The most

Low friction in self-mated silicon carbide tribosystem using nanodiamond as lubricating additive in water

Nanodiamond particles(NDPs)have been considered as a potential lubricant additive to various tribological applications,such as water lubrication systems.In this study,the tribological properties of silicon carbide(SiC)lubricated by NDPs dispersed in water are investigated utilizing the ball-on-disk tribometer.It is found that the slight addition of NDP to water(i.e.,0.001 wt%)can distinctly accelerate the running-in process,which is necessary to achieve a friction coefficient(μ)as low as 0.01.This study also discusses two NDP functional terminations—hydroxyl and carboxyl.It is demonstrated that the use of carboxyl-terminated NDP over a wide range of concentration(0.001 wt%-1 wt%)yields a low friction force.In contrast,the ideal effective concentration of hydroxyl-terminated NDP is considerably limited because agglomeration in this material is more probable to occur than in the former.Meanwhile,when utilizing NDPs,the input friction energy(P_(in),defined as the product of sliding speed and applied load)is found to have an essential function.Several sliding tests were implemented at various P_(in) values(50-1,500 mW)using carboxyl-terminated water-dispersed NDPs.It was observed that theμand wear decreased with increasing P_(in) when 200 mW<P_(in)<1,500 mW.However,when P_(in)<200 mW,low friction with high wear occurs compared with the resulting friction and wear when pure water is used.

Technical Characteristics Analysis for Toyota Prius Hybrid Vehicle

In order to solve the problem effectively that increasing car ownership relies on limited resources like oil and the resulting environmental pollution because of vehicle exhaust,＂New energy vehicles＂is not a new conception which is mentioned frequently and has been used in practical applications in our daily life. As a typical representative of the use of new energy vehicles,Prius,a kind of gas-electric hybrid cars which are made by Toyota is a very typical type in technique and application. Using Prius as an example,we will focus on its chemical reaction principle of electrical energy storage device and evaluation parameters,the structure of driving motors and gives the dqmodel of the electrical machine in dqcoordinates,the structure of dynamic coupling device,convertor assembly which including four kinds of convertor and its function,finally,introducing the working principles and characteristics of the system assembly in this paper.