Adaptive speed control system and method for adapting motor control to changing load conditions

An electric motor system comprising:

• an electric motor;
• a motor speed controller controlling a speed, a torque, and a direction of the electric motor and outputting a first current command and setting a controller gain;
• and
• an adaptive speed control system for automatically adapting control of the electric motor under a changing load condition, the adaptive speed control system comprising
• a load torque observer determining a load torque value due to the changing load condition when the electric motor is operating at a constant speed, wherein the load torque value is used by the motor speed controller to adapt the torque,
• an inertia observer driven by the load torque observer and determining an inertia load value due to the changing load condition when the electric motor is operating at a changing speed, wherein the inertia load value is used by the motor speed controller to adapt the controller gain, and
• an active disturbance input decoupler driven by the load torque observer and processing a second current command and then adding the first current command to the second current command to provide a disturbance rejection in response to a rapidly changing load condition affecting the load torque value when electric motor is operating at a constant speed.

A method comprising:

• controlling a speed, a torque, and a direction of an electric motor and outputting a first current command;
• adapting control of the electric motor under a changing load condition, including
• determining a load torque value due to a changing load condition when the electric motor is operating at a constant speed,
• processing a second current command, and
• adding the first current command to a second current command to provide a disturbance rejection in response to a rapidly changing load condition affecting the load torque value when the electric motor is operating at a constant speed.