SPRUHJ1I January 2013 – October 2021 TMS320F2802-Q1 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1 , TMS320F28052-Q1 , TMS320F28052F , TMS320F28052F-Q1 , TMS320F28052M , TMS320F28052M-Q1 , TMS320F28054-Q1 , TMS320F28054F , TMS320F28054F-Q1 , TMS320F28054M , TMS320F28054M-Q1 , TMS320F2806-Q1 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1
The following plot shows a practical example of PowerWarp, and the power savings related to this mode. The motor under test has the following parameters:
AC Induction Asynchronous Machine (GE 5K33GN2A)
Notice that the motor efficiency with PowerWarp is dramatically improved from 27% to 68% at 1 lb.in of load. Since PowerWarp reduces the ability of the ACIM motor to produce torque, at higher torque demands, energy savings with PowerWarp are also reduced. For the same reason, at rated torque, efficiency curves are identical when PowerWarp is enabled or disabled.
Even though PowerWarp reduces the ability to produce torque, the mechanical power delivered to the shaft is maintained with PowerWarp algorithm enabled, not affecting the mechanical system performance. In other words, from a purely mechanical standpoint, the output mechanical torque and speed are not changed when PowerWarp is enabled. What changes is the electrical power delivered to the motor to produce a certain mechanical output.
As shown in Figure 17-4, motor efficiency is boosted dramatically at lower loads, with a trade-off in dynamic torque and speed response, though the control system remains stable.
The default current slopes are used for this practical example.
#define USER_MAX_CURRENT_SLOPE_POWERWARP (0.3 * USER_MOTOR_RES_EST_CURRENT \
/ USER_IQ_FULL_SCALE_CURRENT_A \
/ USER_TRAJ_FREQ_Hz)
Figure 17-5 shows the time it takes for the FAST estimator to reduce the rated current when PowerWarp is enabled.
It can be seen than the time it takes to reach the lowest current is:
Also, the default has been used for current slopes when PowerWarp is disabled
#define USER_MAX_CURRENT_SLOPE
(USER_MOTOR_RES_EST_CURRENT
/USER_IQ_FULL_SCALE_CURRENT_A
/USER_TRAJ_FREQ_Hz)
Figure 17-6 shows this slope. The time it takes is: (1.3125 – 0.3625)/1 = 1.0 seconds.