Improving Motor and Drive System Performance: a Sourcebook for Industry Acknowledgements
Total Page：16
File Type：pdf, Size：1020Kb
Industrial Technologies Program Improving Motor and Drive System Performance: A Sourcebook for Industry Acknowledgements Improving Motor and Drive System Performance: A Sourcebook for Industry was developed for the U.S. Department of Energy’s (DOE) Industrial Technologies Program (ITP). This project is one in a series of sourcebooks on industri- al systems. Other publications in this series cover fan, compressed air, process heating, pumping, and steam systems. For more information about DOE and ITP, please see Section 4, “Where to Find Help.” This sourcebook was prepared for ITP by technical staff at Lawrence Berkeley National Laboratory and Resource Dynamics Corporation. They wish to thank the many organizations that so generously assisted in data collection and to acknowledge the helpful reviews and other contributions provided by the following individuals: Dale Basso, Rockwell Automation Thomas Bishop, Electrical Apparatus Service Association Austin Bonnett, Electrical Apparatus Service Association Rob Boteler, U.S. Electrical Motors Dennis Bowns, Bowns & Co. Don Casada, Diagnostic Solutions Jasper Fischer, Industrial Motor Repair John Kueck, Oak Ridge National Laboratory John Machelor, Motor-Vations, LLC John Malinowski, Baldor Electric Co. Ilene Mason, Consortium for Energy Efficiency Gil McCoy, Washington State Energy Office Sally McInerney, University of Alabama Cynthia Nyberg, Electrical Apparatus Service Association Howard W. Penrose, Ph.D., SUCCESS by Design Reliability Services Charles Straub, P.E., Marathon Electric Edward J. Swann, Rockwell Automation John Tolbert, Bristol Compressor Chuck Yung, Electrical Apparatus Service Association September 2008 Prepared for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Industrial Technologies Program By Lawrence Berkeley National Laboratory Berkeley, California Resource Dynamics Corporation McLean, Virginia Produced by the National Renewable Energy Laboratory Golden, Colorado Table of Contents Acknowledgements i Quick Start Guide 1 Section 1: Motor and Drive System Basics 3 Overview 3 A System Approach 3 Indications of Poor System Design 4 Types of Electric Motors 4 Motor Operating Characteristics 8 Load Characteristics 10 Matching Motors and Drives to Their Applications 11 Load Duty Cycles 14 Common Motor Selection Problems 15 Summary 16 Section 2: Performance Opportunity Roadmap 17 Overview 17 Efficiency Opportunities 17 Section 3: Motor System Economics 39 Overview 39 Understanding Corporate Policies 39 Measuring the Dollar Impact of Efficiency 39 Presenting the Finances of Efficiency 40 Relating Efficiency to Corporate Priorities 40 Summary 44 Section 4: Where to Find Help 45 Directory of Contacts 49 Resources and Tools 50 Training Courses 60 Appendices 61 Appendix A: Glossary of Basic Motor System Terms 63 Appendix B: Motor Tip Sheets 67 Appendix C: EPAct Efficiency Levels and Premium Efficiency Levels 99 Appendix D: Motor Repair Service Center Checklist 105 Appendix E: Guidelines for Comments 111 Continued > List of Figures Figure 1. 4 Figure 2. 6 Figure 3. 6 Figure 4. 8 Figure 5. 10 Figure 6. 11 Figure 7. 11 Figure 8. 12 Figure 9. 13 Figure 10. 15 Figure 11. 15 Figure 12. 18 Figure 13. 26 Figure 14. 27 Figure 15. 27 Figure 16. 34 Figure 17. 45 Figure 18. 46 List of Tables Table 1. 23 Table 2. 27 Table 3. 29 Table 4. 43 Quick Start Guide Quick Start Guide This sourcebook is designed to provide those who use motor and drive systems with a reference that outlines opportunities to improve system performance. It is not meant to be a comprehensive technical text on motor and drive systems; rather, it provides practical guidelines and information to make readers aware of potential performance improvements. Guidance on how to find more information and assistance is also included. Plant engineers, facility managers, operations personnel, and others whose work involves motor and drive systems will find this sourcebook helpful in assessing the efficiency of their motor and drive applications. Discussions of improvement opportunities in this sourcebook emphasize the connection between operating efficiency and system reliability. For example, a plant project that increases the overall efficiency of a motor and drive system often reduces plant downtime, as well.This is one of several important benefits of efficiency improvements. This sourcebook is divided into four main sections, as outlined below. n Section 1: Motor and Drive System Basics For readers who are unfamiliar with the basics of motor and drive systems or would like a refresher, this section briefly describes important terms, relationships, and system design considerations. It also describes key factors involved in motor and drive selection and system design, and provides an overview of the different types of motors and drives and their applications. Readers who are already familiar with key terms and parameters used in selecting motors and drives, designing systems, and controlling their operation might want to skip this section and go on to the next one. n Section 2: Performance Opportunity Roadmap This section describes the key components of a motor and drive system as well as opportunities for performance improvements. A systems approach is emphasized, rather than a focus on individual components. Guidance is provided in a set of efficiency opportunities, which cover the following topics in separate subsections for easy reference: • Assessing Motor and Drive System Operating Conditions • Establishing a Motor Management Program • Providing Basic Maintenance • Selecting the Right Motor • Using Variable Frequency Drives • Addressing In-Plant Electrical Distribution and Power Quality Issues • Using the Service Center Evaluation Guide n Section 3: Motor System Economics This section provides recommendations on how to propose projects like those described in Section 2 by highlighting for management the favorable economics of motor and drive system improvements. Topics include understanding and identifying corporate priorities, relating those priorities to efficiency, and clarifying the financial aspects of efficiency improvements, including life-cycle costs and payback periods. n Section 4: Where to Find Help Section 4 provides a directory of associations and other organizations associated with motors and drives and their markets. This section also lists helpful resources for more information, tools, software, videos, and training opportunities. Improving Motor and Drive System Performance: A Sourcebook for Industry 1 n Appendices This sourcebook contains five appendices: • Appendix A is a glossary of terms used in discussing motor and drive systems; these terms appear in bold type when they are first mentioned in the text. • Appendix B contains a series of motor and drive system tip sheets. Developed by the U.S. Department of Energy (DOE), these tip sheets discuss opportunities for improving the efficiency and performance of motor systems, but in less detail than the efficiency opportunities described in Section 2. • Appendix C provides Energy Policy Act (EPAct) efficiency levels for motors up to 200 horsepower (hp) in size, along with National Electrical Manufacturers Association (NEMA) Premium® motor efficiency levels. • Appendix D includes a checklist for motor repair facilities. • Appendix E provides guidelines for submitting suggested changes and improvements to the sourcebook. Section 1: Motor and Drive System Basics equipment that can meet worst-case needs to evaluating Section 1: Motor and Drive whether components can be configured to maintain high System Basics performance over the entire range of operating conditions. A basic premise of a systems approach is that industrial Overview systems usually do not operate under one condition all the time. Motor and drive system loads often vary according Electric motors, taken together, make up the single largest to cyclical production demands, environmental conditions, end use of electricity in the United States. In industrial changes in customer requirements, and so on. To optimize applications, electric motors account for roughly 60% of system performance, the engineer must configure the system electricity consumption; in the process industries, electric to avoid inefficiencies and energy losses. For example, motors account for more than 70% of electricity use. motors that typically run at more than one-half to full Electric motors provide efficient, reliable, long-lasting load usually operate much more efficiently than they do service, and most require comparatively little maintenance. at less than one-half load or into their service factor. The Despite these advantages, however, they can be inefficient service factor is a multiplier that indicates the percentage and costly to operate if they are not properly selected of horsepower (or other nameplate rating, such as torque) and maintained. Industrial plants can avoid unnecessary above full load at which a motor can operate without increases in energy consumption, maintenance, and costs, causing a failure under certain conditions. Common service by selecting motors that are well suited to their applications factor values are 1.10 and 1.15. Other avoidable losses and making sure that they are well maintained. include waste heat and flow energy that dissipates without performing useful work. A System Approach For example, suppose that a motor-driven pump supplies Cost-effective operation and maintenance of a motor and water to several heat exchangers and has a flow requirement