Induction machine having a customized field-forming current component

A control device including a control program comprising machine code encoded on the control device for a converter connecting a stator winding of an induction machine to a power-supply network which, when processed by the control device, causes operation of the induction machine, the machine code comprising:

• machine code for controlling the converter such that the converter connects a stator winding to a power-supply network such that a stator current flows within the stator winding, a stator current having a field-forming current component and a torque-forming current component;
• machine code for controlling the converter such that, during load periods, a torque acts between a stator and a rotor, which lies above a predetermined limit torque and its maximum is several times the predetermined limit torque, the load periods being separated from each other by periods of rest;
• machine code for controlling the converter during the periods of rest such that a torque acts between the stator and the rotor, which is below the predetermined limit torque;
• and
• machine code for controlling the converter at least at a beginning of the periods of rest such that the field-forming current component has a nominal value;
• and
• machine code for controlling the converter during the load periods such that the field-forming current component has a lower value than the nominal value.

A control device for a converter connecting a stator winding of an induction machine to a power-supply network, wherein the control device is programmed with a control program which, when processed by the control device, causes the control device to:

• control the converter such that the converter connects a stator winding to a power-supply network such that a stator current flows within the stator winding, a stator current having a field-forming current component and a torque-forming current component;
• control the converter such that, during load periods, a torque acts between the stator and the rotor, which lies above a predetermined limit torque and its maximum is several times the predetermined limit torque, the load periods being separated from each other by periods of rest;
• control the converter during the periods of rest such that a torque acts between the stator and the rotor, which is below the predetermined limit torque;
• and
• control the converter at least at a beginning of the periods of rest such that the field-forming current component has a nominal value;
• and
• control the converter during the load periods such that the field-forming current component has a lower value than the nominal value.

An induction machine, comprising:

• a stator;
• and
• a rotor having a rotor time constant defined by a rotor inductance of the rotor and a rotor resistance of the rotor, the rotor having:
• a stator winding arranged within the stator;
• a converter assigned to the induction machine, via which the stator winding is connectable to a power-supply network such that a stator current flows within the stator winding;
• and
• a control device assigned to the converter and programmed with a control program which, when processed by the control device, causes the control device to:
• control the converter such that the converter connects the stator winding to the power-supply network such that the stator current flows within the stator winding, the stator current having a field-forming current component and a torque-forming current component;
• control the converter such that, during load periods, a torque acts between the stator and the rotor, which lies above a predetermined limit torque and its maximum is several times the predetermined limit torque, the load periods being separated from each other by periods of rest;
• control the converter during the periods of rest such that the torque acts between the stator and the rotor, which is below the predetermined limit torque;
• control the converter at least at a beginning of the periods of rest such that the field-forming current component has a nominal value;
• and
• control the converter during the load periods such that the field-forming current component has a lower value than the nominal value.