Method and arrangement for adaptive load change compensation
AssigneeABB Industry Oy
InventorHeikki Rasimus
Life of this patent
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Abstract
A method and arrangement for adaptively compensating for load changes, particularly in connection with an electric motor drive which comprises a motor, the shaft of the motor being connected to a load (3) having a known moment of inertia; a device (2), such as an inverter, to control the motor, a torque controller being arranged in connection with the device; and a speed controller (1) arranged to control the speed of the motor. The method comprises steps of determining, during the load change, an estimate (Mh) for an external torque disturbance which causes load changes, and employing the torque disturbance estimate (Mh) determined during the previous load change for compensating for the external torque disturbance in controlling the torque of the motor.
Claims13
A method of adaptively compensating for a transient phase causing a load change, particularly in connection with an electric motor drive which comprises a motor, the shaft of the motor being connected to a load having a known moment of inertia;
- a device, such as an inverter, to control the motor, a torque controller being arranged in connection with the device;
- and a speed controller arranged to control the speed of the motor, the method comprising the steps of:
- receiving an indication of the start of the transient phase which causes the load to change;
- determining, during the load change only, an estimate (Mh) for an external torque disturbance which causes the load change, and employing the estimate (Mhl) determined during the previous load change for compensating for the external torque disturbance in controlling the torque of the motor.
An arrangement for adaptively compensating for transient load changes an electric motor having a shaft connected to a load having a known moment of inertia comprising:
- a device for receiving an indication of the start of a transient load change for controlling the motor including, a torque controller for producing an output torque;
- and a speed controller arranged to control the speed of the motor;
- an adder, the speed controller receiving as its input a difference (ve) of a speed command (vo) and an actual value (v) of the speed of the motor from the adder unit;
- and a compensator arranged to determine during a load change only a torque compensation (Mk) for compensating for an external torque disturbance on the basis of a torque disturbance (Mh) to which the load is subjected, the output torque (Mmot) of the device controlling the motor, and a moment of inertia (J) and an angular speed (ω) of the load.
A method of adaptively compensating for load changes in an electric drive wherein the shaft of the motor is connectable to a load having a known moment of inertia comprising the steps of:
- receiving an indication of the start of the transient phase which causes the load to change;
- determining, during a load change only, an estimate (Mh) of an external torque disturbance which causes the corresponding load change, and
- controlling the torque of the motor by employing the estimate (Mh) determined during the corresponding load change for compensating for the external disturbance.
Apparatus for adaptively compensating for transient load changes, in an electric motor drive wherein a motor has a shaft connectable to a load having a known moment of inertia comprising:
- means for receiving an indication of the start of a load change for controlling the motor;
- a compensator for determining during such load change only a torque compensation (Mk) on the basis of a torque disturbance (Mh) to which the load is subjected, an output torque (Mmot), and a moment of inertia (j) and an angular speed (ω) of the load, and applying the torque compensation of the motor.
A method of adaptively compensating for periodic transient phases causing load changes in an electric motor drive wherein the motor has a shaft connected to a load having a known moment of inertia;
- control means operatively coupled to the motor produces a torque signal;
- and a speed controller operatively coupled to the control means produces a speed control signal for controlling the speed of the motor, comprising the steps of:
- determining, during the load change only, an estimate for an external torque disturbance which causes the load to change during the corresponding transient phase;
- employing a compensator responsive to the estimate determined during the previous transient phase for producing a compensating signal for the control means to control the torque of the motor;
- and
- providing inputs to the compensator based upon the actual motor speed and the moment of inertia.
Dependencies are inferred from the claim text.