TEMPERATURE DETERMINATION METHOD FOR MAGNET TEMPERATURES ON MAGNETS OF ELECTRIC MOTORS

A temperature determination method for magnet temperatures on magnets of electric motors has a test mode. A first voltage is applied to a test winding of a test motor with test magnets for impressing a first voltage-time area at first angles of a test motor rotating field. The test magnets are subject to a predefined magnet temperature. First current values are ascertained at the first angles and stored based on the predefined magnet temperature. In a normal mode, a second voltage is applied to a motor winding of an operations motor with motor magnets for impressing a second voltage-time area at second angles of a motor rotating field. The motor magnets have an operation-dependent magnet temperature. Second current values are determined at the second angles and stored based on the operation-dependent magnet temperature. The operation-dependent magnet temperature is determined by comparing a second current value with a first current value.