Motors are (by far) the largest electrical energy consumers used in industry (74%), using 30% the world’s electrical energy production. 2 A toll must be paid in the form of resistive losses in the wire (I 2R losses) for every Watt traveling through a conductor, so more efficient motor applications decrease both energy consumption at the load and line losses to the load. Even minor improvements in an electric motor’s efficiency can provide substantial long-term savings, reaching from a motor’s terminals to the remote electric generator(s) providing energy to the motor. Because motors are often the largest energy consuming loads in commercial or industrial facilities, they are an obvious choice to initiate energy efficiency improvements. Motor drives, sometimes referred to as VSDs, adjustable speed drives (ASDs), adjustable frequency drives (AFDs), or variable frequency drives (VFDs), are an effective method to reduce the energy consumption of motor loads in facilities. Drives are used to control the voltage, current, and/or frequency to motors, regulating their speed and torque. By regulating a motor’s behavior in this way, substantial improvements in the motor’s efficiency and performance can be attained. Drives provide an array of benefits including:
• Improved control
• Better reliability
• Greater flexibility for what is controlled (e.g., torque, speed, precision, etc.)
• Decreased emissions (subject to the electrical generation fuel source)
• Reduced OpEx and CapEx (for a given application), and of course
• Lower energy consumption (sometimes greater than 50%)