Patent ID: 8054014

Claim:
A control system for a permanent-magnet electrical machine ( 1 ), having a functional computer ( 3 ), a monitoring computer ( 4 ) in communication with the functional computer ( 3 ), a programmable logic module ( 5 ) connected to the functional computer ( 3 ) and the monitoring computer ( 4 ), a rotation speed sensor ( 6 ) associated with the electrical machine ( 1 ) for detecting a rotation speed D 1 of the electrical machine ( 1 ), and an output stage ( 2 ), which is connected to the programmable logic module ( 5 ) and the electrical machine ( 1 ) for supplying power thereto and which can be switched off, the output stage ( 2 ) having three upper circuit breakers ( 2 o 1 , 2 o 2 , 2 o 3 ) and three lower circuit breakers ( 2 u 1 , 2 u 2 , 2 u 3 ), for disconnecting the electrical machine ( 1 ) when the functional computer ( 3 ) or the monitoring computer ( 4 ) identifies a fault, and means for switching off the electrical machine ( 1 ) by subjecting the output stage ( 2 ) to a three-phase short circuit by shorting one of the three upper circuit breakers ( 2 o 1 , 2 o 2 , 2 o 3 ) and the three lower circuit breakers ( 2 u 1 , 2 u 2 , 2 u 3 ) when the rotation speed D 1 does not fall below a definable limit value GR 1 or when a voltage U_DC of the output stage ( 2 ) exceeds a limit value Umax, and all the circuit breakers ( 2 o 1 , 2 o 2 , 2 o 3 , 2 u 1 , 2 u 2 , 2 u 3 ) of the output stage ( 2 ) being openable, in order to fully disconnect the electrical machine ( 1 ), when the rotation speed (D 1 ) of the electric machine ( 1 ) is below the limit value GR 1 and a voltage U_DC of the output stage ( 2 ) does not exceed a limit value Umax.