Efficiency improvement measures analysis of induction motors

Motor structure was improved for increasing its efficiency and the impact of these measurements to motor operating characteristics was analyzed. It is shown that increasing wire diameter can reduce stator copper loss and increase efficiency effectively within a limited fill factor. Reducing gap thickness can increase motor efficiency and power factor but will increase locked-rotor current ratio. Increasing iron core length properly can raise motor efficiency and power factor, but it will reduce locked-rotor torque ratio and breakdown torque ratio. Using cast copper instead of cast aluminum as rotor bars and end rings can increase efficiency but will reduce locked-rotor torque ratio and raise locked-rotor current ratio at the same time.