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

摘要

A process and device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor are described. The process continuously checks, when a rotation speed controller is active and for a predetermined constant rotation speed setpoint, several conditions, either alone or in combination, and generates an error signal if the particular condition or the combination of conditions, when continuously checked, is/are always satisfied during at least a predetermined time interval. These conditions include: determining if the magnitude of a measured deviation in the rotation speed between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value; if the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value; and if the magnitude of a measured acceleration value and/or the magnitude of a torque-producing current increases or reaches a limit value.