A frequency converter with variable output vfd or adjustable, Frequency drive afd, Variable, Voltage/variable, Variable frequency vvvf, Frequency controller, Ac drive drive, Micro drive or inverter drive belongs to a class of adjustable, Speed drive used in electro, Mechanical drive systems to control ac motor speed and torque by varying motor input frequency and voltage. 1 2 3 4 vfds serve a role within applications ranging from small appliances to large compressors. About 25% of the planet’s electrical energy is consumed by electric motors in industrial applications, That may be more efficient when using vfds in centrifugal load service, 5 however, The global market penetration for all applications of vfds is relatively small.