Method for operating a drive train, and drive train

A method for operating a drive train, including an electric motor, a load driven by the electric motor and/or a gear unit driven by the electric motor, and a sensor for acquiring an angular position of a rotor of the electric motor, comprising:

• supplying a motor voltage to the electric motor via a converter to achieve a torque setpoint value;
• determining an angular velocity actual value and an angular acceleration actual value from acquired values of the angular position of the rotor;
• determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference between the angular velocity actual value and an angular velocity setpoint value is supplied;
• determining the total moment of inertia as a sum of a moment of inertia of the drive train without a load and a moment of inertia of the load;
• determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train.

A method for operating a drive train, including an electric motor, a load driven by electric motor and/or by a gear unit driven by the electric motor, the load being variable over time, and a sensor for acquiring an angular position of a rotor of the electric motor, a moment of inertia of the drive train without a load being constant over time and being predefined as a parameter, a motor voltage being made available to the electric motor by a converter to achieving a torque setpoint value, comprising:

• determining an angular velocity actual value and an angular acceleration actual value from values of the angular position of the rotor acquired by the sensor;
• determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference is supplied between the angular velocity acceleration actual value and the angular velocity setpoint value;
• determining the total moment of inertia as a sum of the moment of inertia of the drive train without a load and the moment of inertia of the load;
• determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train;
• determining a value of the moment of inertia of the load, including:
• determining the torque actual value;
• predefining as a parameter the moment of inertia of the drive train without a load;
• and
• determining the moment of inertia of the load as a quotient, reduced by the moment of inertia of the drive train, of the torque actual value and the angular acceleration actual value;
• and
• after determining the value of the moment of inertia of the load, determining an updated value of the moment of inertia of the load, including:
• at a first instant, determining the moment of inertia of the load as a first quotient, reduced by the moment of inertia of the drive train, of the torque actual value and the angular acceleration actual value, the angular acceleration actual value lying in a first value range;
• at a second instant following the first instant, determining the moment of inertia of the load as a second quotient, reduced by the moment of inertia of the drive train, of the torque actual value and the angular acceleration actual value, the angular acceleration value lying in a second value range;
• and
• determining an updated moment of inertia of the load by adding to a previously determined value of the moment of inertia of the load a difference between the second quotient and the first quotient.