摘要 |
To determine the flux in the air gap of an electrical machine having distributed stator windings, the voltages across two coils of a phase belt in certain phases of the stator are measured and the voltage across one coil in each phase belt is subtracted from the voltage in the other coil. The voltage differences are integrated to provide a measure of the air gap flux. Measurement of the entire air gap flux about the machine can be obtained utilizing two coils in a phase belt per phase of the machine. The instantaneous electromagnetic torque in the machine can be calculated directly as a function of the calculated air gap flux and of the currents in the stator windings. Such flux and torque measurements are obtained utilizing electrical connections to the existing coils of the machine, without the need to modify the machine by adding further windings or sensors. The flux and torque signals so obtained may be utilized in motor controllers, and are particularly useful for control of AC induction motors.
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