Torque estimating system for synchronous electric motor

• Main Authors: Briz Del Blanco, Fernando, Yoshida, Hideo, Díaz Reigosa, David, Kato, Takashi
• Format: Patent
• Language: English; French; German
• Published: 29.08.2018
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; GENERATION; MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING

A torque estimating system for a synchronous electric motor having a permanent magnet comprises: a superimposing unit (5) configured to superimpose a voltage or current of a frequency different from a frequency of a fundamental wave driving the synchronous electric motor on at least a d-axis of the synchronous electric motor; a magnet temperature estimating unit (14) configured to estimate a temperature of the permanent magnet from the superimposed voltage or current and a current or voltage obtained by the superimposing; and a torque estimating unit (15) configured to estimate a torque of the synchronous electric motor from the estimated temperature of the permanent magnet.