Performances Study of Speed and Torque Control of an Asynchronous Machine by Oriented Stator Flux

Abstract

In this article, we proceeded to the study and analyzing of the speed and torque control performance of an asynchronous machine. This research presents in particular a new control scheme, whose principle is to control the operation of this machine similarly to a DC machine. Many control methods dealing this subject have been proposed in the publications and studies, the control by orientation of the rotor flux remains the most used given the high dynamic performance it offers for a wide range of applications. In this respect, our strategy of orienting the stator flux has shown by numerical simulation, the robustness of the proposed control against parametric variations as well as the working conditions. The results make it possible to illustrate, both in terms of performance and robustness, the contribution of such a control to impose on the machine dynamic behaviors similar to those of a control with oriented rotor flux. The objective of the regulators (PI) that we used is to regulate the stator flux and the speed as well as the torque.

Appendix

• (1) The matrix representation of the model of the asynchronous machine established in the oriented rotor flux domain:

$$ \frac{{dX^{{\prime }} }}{d} = [A^{{^{{\prime }} }} ]X^{{^{{\prime }} }} + [B^{{^{{\prime }} }} ]U $$

(23)

$$ [A^{{\prime }} ] = \left[ {\begin{array}{*{20}l} { - \gamma^{{\prime }} } \hfill & {w_{s} } \hfill & {a_{1}^{{\prime }} } \hfill & {a_{2} w_{m} } \hfill \\ { - w_{s} } \hfill & { - \gamma^{{\prime }} } \hfill & { - a_{2} w_{m} } \hfill & {a_{1}^{{\prime }} } \hfill \\ {\frac{M}{{T_{r} }}} \hfill & 0 \hfill & { - \frac{1}{{T_{r} }}} \hfill & {w_{r} } \hfill \\ 0 \hfill & {\frac{M}{{T_{r} }}} \hfill & { - w_{r} } \hfill & { - \frac{1}{{T_{r} }}} \hfill \\ \end{array} } \right],\,X^{{\prime }} = \left[ {\begin{array}{*{20}l} {I_{sd} } \hfill \\ {I_{sq} } \hfill \\ {\emptyset_{rd} } \hfill \\ {\emptyset_{rq} } \hfill \\ \end{array} } \right][B^{{\prime }} ] = \left[ {\begin{array}{*{20}l} {a_{3}^{{\prime }} } \hfill & 0 \hfill & { - a_{2} } \hfill & 0 \hfill \\ 0 \hfill & {a_{3}^{{\prime }} } \hfill & 0 \hfill & { - a_{2} } \hfill \\ 0 \hfill & 0 \hfill & 1 \hfill & 0 \hfill \\ 0 \hfill & 0 \hfill & 0 \hfill & 1 \hfill \\ \end{array} } \right],\,U = \left[ {\begin{array}{*{20}l} {V_{sd} } \hfill \\ {V_{sq} } \hfill \\ {V_{rd} } \hfill \\ {V_{rq} } \hfill \\ \end{array} } \right] $$

With: $\gamma^{{\prime }} = \left[ {\frac{1}{{T_{s} \sigma }} + \frac{(1 - \sigma }{{T_{r} \sigma }}} \right],a_{1}^{{\prime }} = \frac{1}{{T_{r} M}}\frac{(1 - \sigma )}{\sigma },a_{3}^{{\prime }} = \frac{1}{{\sigma l_{s} }}$

• (2) The data of the asynchronous machine with two pole pairs: 4 kW, 220/380 V – 50 Hz, 15/8.6 A, 1440 tr/min, C_em = 25 Nm.

Parameters: R_s = 1.2 Ω, R_r = 1.8 Ω, L_s = 0.1554 H, L_r = 0.1568 H, M = 0.15 H, J = 0.07 kg m², f = 0.0001 N.m.s/rd.