Patent attributes
An improved system for controlling operation of a motor with a motor drive is disclosed. The motor drive includes a control module having an inner control loop operable to generate a torque reference signal and a load observer operable to generate an estimate of the torque present on the motor. The torque estimate is summed with the torque reference signal to generate a modified torque reference. The bandwidth of the load observer is set wide enough to generate the estimated torque over a desired operating range of the motor. The control module may also include a low pass filter and at least one tracking notch filter. The low pass filter suppresses vibrations at high frequencies, and the tracking notch filter suppresses resonances present at frequencies above the bandwidth of the load observer and within the pass band of the low pass filter.