Motors / Drives

Motors and drives: Driving forces

The editors of Control search the world wide web to find the latest online resources on motors and drives.


Motors and drives have been moving up to variable-speed control for better accuracy, but now they're also increasing power density and efficiency, and even coordinating more closely with PLCs and intelligent systems, according to Control executive editor Jim Montague. Learn how process operations as diverse a cement suppliers, iron ore mines, refineries and natural gas producers are using the latest drive technology in increase efficiency, reduce power usage and improve reliability. Read "Motors and Drives Grow Up and Graduate."


This three-minute video from ABB explains the basics of motor and drive sizing. Learn the three steps around application requirements, sizing the motor and then selecting the drive. Why is torque so important? What is the difference between variable and constant? Find out here.


Learn what factors contribute to the total cost of ownership of a drive; how to calculate the net present value; all about the inverse relationship between reliability and TCO; and how longevity of product and customer service and support affect TCO. Medium-voltage, variable-frequency drives have many benefits, such as energy efficiency and process control, however, quantifying  them challenges engineers to identify which solution is the most affordable and reaps the greatest rewards. It's vital to your success and your company's profitability that you know your TCO. Find out more.


This series of videos from Texas Instruments introduces the different types of motors used in the industry—DC, brushless DC, stepper, permanent magnet synchronous and AC induction. To gather a better understanding of motors, differences in these motors with advantages and disadvantages of each are shown. Basic motor drive circuits from full H-Bridge drive to half-bridge for three-phase motors are covered. Other drive concepts such as six-step commutation along with drive issues such as current recirculation are included. Field-oriented control and how it's progressed with improving technology is also discussed. The direct link to the series is found at
Texas Instruments


Selecting the right motor and drive combination saves energy and improves performance. This tutorial covers the basics of AC induction motors, torque and horsepower, motors and loss-reduction techniques, motor economics and adjustable-speed drive systems. The site also contains links to other motor and drive subject tutorials and lectures. Go to


This link takes you to two tutorials on DC motor subjects. “DC Motor Calculations” details the steps needed to calculate mechanical power requirements, torque-speed curves, numerical calculations and calculation samples. “How to Select a DC Motor” covers the necessary available voltage, output required torque and speed, the required physical envelope, and operating temperatures. Go to


This 39-page PDF, “Motor Efficiency, Selection and Management: A Guidebook for Industrial Efficiency Programs” is for those that need a basic, non-engineering overview of general-purpose motors, motor efficiency and motor management fundamentals, particularly in the context of optimizing motor system performance. It's at
Consortium for Energy Efficiency


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