Process and device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor

A process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value;
• and
• generating an error signal if the magnitude increases or reaches the limit value during at least a predetermined time interval, said error signal indicating that the motor is in a runaway condition.

A process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if the magnitude of a measured acceleration value increases or reaches a limit value;
• and
• generating an error signal if the magnitude increases or reaches the limit value during at least a predetermined time interval, said error signal indicating that the motor is in a runaway condition.

A process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if the magnitude of a torque-producing current increases or reaches a limit value;
• and
• generating an error signal if the magnitude increases or reaches the limit value during at least a predetermined time interval, said error signal indicating that the motor is in a runaway condition.

A process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if a logical AND-operation between at least two of the following conditions produces the logical value “TRUE”:
• (a) a signal representing a rotation speed between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value;
• (b) a signal representing the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value;
• (c) a signal representing the magnitude of a measured acceleration value increases or reaches a limit value, and
• (d) a signal representing the magnitude of a torque-producing current increases or reaches a limit value;
• and
• generating an error signal if the logical value “TRUE” between the at least two conditions is present during at least a predetermined time interval, said error signal indicating that the motor is in a runaway condition.

A process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if at least one of the following conditions is satisfied during at least a predetermined time interval:
• (a) a signal representing a rotation speed difference between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value;
• (b) a signal representing the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value;
• (c) a signal representing the magnitude of a measured acceleration value increases or reaches a limit value, and
• (d) a signal representing the magnitude of a torque-producing current increases or reaches a limit value;
• and
• generating an error signal if one or more of the conditions are satisfied, said error signal indicating that the motor is in a runaway condition.

A device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, comprising:

• a computing device having at least one input and an output;
• a rotation speed controller having an activation input and an output, with the output of the rotation speed controller providing a signal to at least one input of the computing device;
• and
• a controller having an input and an output, with the input being connected to the output of the computing device and the output being connected to the activation input of the rotation speed controller;
• wherein the rotation speed controller is set to a predetermined constant rotation speed setpoint and when activated constantly checks if at least one of the following conditions is satisfied during at least a predetermined time interval:
• (a) a signal representing a rotation speed difference between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value;
• (b) a signal representing the magnitude of a control variable present at the output of the rotation speed controller increases or reaches a limit value;
• (c) a signal representing the magnitude of a measured acceleration value increases or reaches a limit value, and
• (d) a signal representing the magnitude of a torque-producing current of the motor increases or reaches a limit value;
• and
• wherein the computing device generates—if one or more of the conditions are satisfied—an error signal which causes the controller to deactivate the rotation speed controller in order to bring the motor to a stop.

A process for identifying an unstable condition of a closed-loop control circuit that controls a rotation-speed of a permanent-excited synchronous motor, comprising the steps of:

• activating a rotation speed controller and setting the rotation speed controller to a predetermined constant rotation speed setpoint;
• constantly checking if at least one of the following conditions is satisfied during at least a predetermined time interval:
• (a) a signal representing a rotation speed difference between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value;
• (b) a signal representing the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value;
• (c) a signal representing the magnitude of a measured acceleration value increases or reaches a limit value, and
• (d) a signal representing the magnitude of a torque-producing current increases or reaches a limit value;
• and
• generating an error signal if one or more of the conditions are satisfied, said error signal indicating that the closed-loop control circuit is unstable.