Cement, Energy and Environment

Enter the Variable-Speed Drive The AC induction motor has a flaw when operating in its normal-rated torque region. At very light application loads, it draws nearly the same current at rated load. Power efficiencies could drop to 35 percent from its rated efficiency of 90 percent to 95 percent, depending on an AC motor's hp output. The emergence of the 3-phase adjustable or variable speed drive (VSD) in the late 1980's provided the AC motor with a much wider speed operation. The variable speed drive is a solid– state power conversion unit that controls the frequency, voltage and current into a 3-phase induction motor. Typical VSDs can seamlessly vary volts and frequency to eliminate the difficulty in high current and low starting torque in AC induction motors. Field weakening , pulse width modulation (PWM), and current control provides other drive strategies available to be more controllable and to maintain high power efficiency over variable load. 300 D w ::> 250 a 0:: 200 0 1- 150 1- z A orB w 100 u 0:: w 50 a. 0 0 so 100 PERCENT SYNCHRONOUS SPEED The AC induction motor is the most popular motor for use in a wide range of speed-based applications. Simple in design and rugged in construction, lower in cost and in maintenance - the AC induction motor continues to dominate industrial and powered home applications. Courtesy: Gear Technology India, Vol. -3, Issue -1, February 2014, Pp. 48-49 Energy Conservation COGENERATION CASE STUDIES HANDBOOK (EUROPE) The CHP Directive 2004/08/EC outlines an enabling policy framework for the European Union to expand the deployment of cogeneration in member states. CHP is a highly energy efficient approach to generating electricity and providing useful heat. It is a key enabler for improving the efficiency and sustainability of electricity production from all fuels. One of the CHP Directive's main achievements has been to deliver a clear Europe wide statement on the potential for further CHP growth. The European member states have identified the opportunity to double CHP, thereby contributing a minimum primary energy saving of 35 mtoe to Europe's economy and contributing a full 10% plus to Europe's overall savings target of 20% by 2020. The question remains: how is this to be achieved? By focusing on the identification of potential, non-economic barriers, financial modelling and identification of best practices, the CODE project can begin to answer this question. CODE is an lEE-sponsored project which looks at implementation of the CHP Directive in all 27 member states. The project's first phase assessed how well the CHP Directive had been implemented in member states and analysed studies of its potential reported across Europe. The CODE project was the first to show that European member states believe there is the economic potential to double CHP in Europe by 2020. This means that 22% of Europe's delivered electricity would be generated in the CHP mode by 2020. A following phase examined the economic incentives for CHP available in Europe. The study looked at standard projects and their financial return in each member state, highl ighting the diversity of funding approaches and the difficulty in designing a support scheme to stimulate the full capacity range of projects. The subject of this report is the best practice cases identified in the CODE project and they provide an important insight into what drives a successful CHP project. The case studies show the wonderful diversity of CHP applications and how this enables new energy behaviors and its role close to citizens embedded in the economy and the community. These studies also allow us to explore why in some cases, despite the competitive , economic and communication barriers, a project will be built, allowing us to better understand where action by industry, suppliers, communicators and policymakers should be prioritized. Courtesy: Industrial Cogeneration India, January 2014, Pg. No: 15 '