The hardware tests demonstrate that the control architecture offered by AC Kinetics breaks free from many of the conventional limitations in an AC drive, enabling it to surpass the dynamic performance, disturbance rejection, and energy efficiency achieved by leading industry drives – all at the same time.
Reference Tracking
To demonstrate the reference tracking capability of each drive, an AC induction motor coupled to a large inertia was commanded to follow a modified EPA city traffic cycle. The velocity tracking error and energy consumption were measured and compared for each drive. The results are shown below.
The AC Kinetics drive used about half of the energy of competitor commercial drives, while also having the smallest tracking error.
Sensitivity to Load Disturbances
To establish each drive’s sensitivity to unpredicted load disturbances, the drives were commanded to hold a constant velocity with the motor shaft coupled to a large inertia. A full-scale load was then instantly applied. This constant load was used for several seconds and then removed. The load disturbance moved the shaft velocity off its reference value, and the drives attempt to recover to the reference speed. The various drive responses to the large unpredicted load as it is applied to the motor shaft commanded to maintain 350 RPM are shown below.
The peak velocity tracking error and time to re-settle were measured for each drive. The results are shown below.
The various drive responses to the large unpredicted load as it is removed from the motor shaft commanded to maintain 350 RPM are shown below.
The peak velocity tracking error and time to re-settle are shown below.
The various drive responses to the large unpredicted load as it is applied to the motor shaft commanded to maintain 1000 RPM are shown below.
The peak velocity tracking error and time to re-settle are shown below.
The various drive responses to the large unpredicted load as it is removed from the motor shaft commanded to maintain 1000 RPM are shown below.
The peak velocity tracking error and time to re-settle are shown below.
At both tested operating points of 350 rpm and 1000 rpm, the AC Kinetics drive had the best response to unpredicted load disturbances with the smallest peak velocity tracking error and the quickest time to re-settle.
Saturation Response
To characterize each drive’s response when driven into saturation, each was configured without slew rate limits and subjected to a large step command in velocity. Peak overshoot, settling time and energy consumption were measured for each drive.
The Energy Consumed during the saturation test is shown below.
The AC Kinetics drive achieved the smallest peak overshoot and fastest settling time, while using considerably less energy that other leading commercial drives used for the exact same transition in velocity.
Steady State
To test to steady-state efficiency of each drive, each was operated at 30 different speed and load combinations. Energy consumption was measured for each drive at each of these operating points and then plotted to create an efficiency map. Each plot below is the steady state efficiency map for a selected load. (Note: the data for Drive C will be added shortly when testing is completed.)
Across all operating points, the AC Kinetics drive consumed the smallest amount of energy, while maintaining its excellent performance characteristics.
The revolutionary AC Kinetics drive control software makes high performance and minimal energy consumption simultaneously achievable, and it accomplishes this without the uncertainty of hand-tuning.