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Ebook High performance control of AC drives with matlab simulink models: Part 2

(BQ) Part 2 book "High performance control of AC drives with matlab simulink models" has contents: Directtorque control of AC machines, non linear control of electrical machines using non linear feedback, five phase induction motor drive system, sensorless speed control of AC machines, selected problems of induction motor drives with voltage inverter and inverter output filters. | 5 Direct Torque Control of AC Machines Truc Phamdinh 5.1 Preliminary Remarks Theoretical principles of direct torque control (DTC) for high performance drives were introduced in the second half of the 1980s [1–3]. Compared with field-oriented control, with origins that date back to the beginning of the 1970s, DTC is a significantly newer concept. It took almost 20 years for vector control to gain acceptance by industry. In contrast, the concept of DTC has been taken on board by industry relatively quickly in only ten years [4,5]. While vector control predominantly relies on mathematical modeling of an induction machine, DTC makes direct use of physical interactions that take place within the integrated system of the machine and its supply. The DTC scheme adopts simple signal processing methods and relies entirely on the non-ideal nature of the power source that is uses to supply an induction machine within the variable speed drive system (two-level or three-level voltage source inverters, matrix converters, etc.). It can therefore be applied to power electronic converter-fed machines only. The on-off control of converter switches is used for the decoupling of the non-linear structure of the induction machine [6]. The most frequently discussed and used power electronic converter in DTC drives is a voltage source inverter. DTC takes a different look at the induction machine and the associated power electronic converter. First, it recognizes that regardless of how the inverter is controlled, it is by default a voltage source rather than a current source. Next, it dispenses with one of the main characteristics of the vector control indirect flux and torque control by means of two stator current components. In essence, DTC recognizes that if flux and torque can be controlled indirectly by these two current components, then there is no reason why it should not be possible to control flux and torque directly, without intermediate current control loops. The control part of a .