Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...

DSP implementation of DTC-SVM control
Experimental results presented in Figures 7.22-7.29 well confirm the effectiveness of
developed controller synthesis methodology and proper operation of speed control loop
for parallel DTC-SVM structure.
Sensorless speed operation
Dynamic tests for the speed control loop without motion sensor were measured for
sampling time T = 200µ
s. Please note that the digital speed controller parameters were
s
selected exactly like for operation with speed sensor according to Table 5.5 (see
Chapter 5.4).
The results of speed estimator dynamic test are presented in Fig. 7.30. In this test speed
controller operates with the encoder signal in feedback and speed estimator works in
open loop fashion.
Figure 7.30. Experimental dynamic test of the speed estimation. Speed reversal Ω =± 300rpm
From the top: 1- reference speed (180rpm/div), 2- measured speed (180rpm/div), 3 - estimated
speed (180rpm/div), 4- error of estimated speed (5%/div).
m
The typical dynamic performance tests of sensorless DTC-SVM drive has been
illustrated in Fig. 7.31-7.36. Start up and breaking to zero speed for different speed level
are shown in Fig. 7.31 and 7.33. Also, the speed reversal for low (Fig. 7.32) and
nominal (Fig. 7.34) speed are presented. The half load torque step change tests are
shown in Fig. 7.36 and 7.37.
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