초록 ▼

A method and apparatus used with a motor controller that detects load imbalance at a relatively low speed and, if the degree of load imbalance is greater than a predetermined acceptable maximum degree, produces an alarm signal that indicates an imbalanced load. If the degree of load imbalance is gre

A method and apparatus used with a motor controller that detects load imbalance at a relatively low speed and, if the degree of load imbalance is greater than a predetermined acceptable maximum degree, produces an alarm signal that indicates an imbalanced load. If the degree of load imbalance is greater than the predetermined acceptable maximum value, the present invention may either attempt to rebalance the load or stops the motor until the balance can be manually adjusted.

대표청구항 ▼

A method to be used with a motor controller for detecting a mechanically unbalanced load, the motor operating at a number of different frequencies including various operating frequencies wherein the operating frequencies are relatively high frequencies, the method comprising the steps of: (a) prior

A method to be used with a motor controller for detecting a mechanically unbalanced load, the motor operating at a number of different frequencies including various operating frequencies wherein the operating frequencies are relatively high frequencies, the method comprising the steps of: (a) prior to increasing the motor speed to any high operating frequency, increasing the motor speed to a test frequency that is substantially less than the operating frequency; (b) maintaining the motor speed substantially equal to the test frequency during a test period; (c) determining whether or not the motor load is mechanically balanced or unbalanced during the test period including the steps of; (i) continuously determining a phase angle between a stator winding voltage and a stator winding current to produce a phase angle spectrum in the form of a phase angle signal: (ii) determining a period of a mechanical cycle of the motor: (iii) determining a difference between the maximum and minimum of the phase angle signal during the mechanical cycle to produce a stability signal: and (iv) comparing the stability signal to an acceptable stability value: (v) if the stability signal is greater than the acceptable stability value, producing a signal indicating that the load is unbalanced; (d) if the stability signal is less than the acceptable stability value, stepping the motor speed up to the operating frequency; and (e) if the stability signal is greater than the acceptable stability value, producing an alarm signal indicating that the load is unbalanced.