Abstract
The theory of field-oriented control of induction motors, which emerged in the early 2000s, is based on a fundamental property of field orientation, which involves decomposing the motor’s output into two independent subsystems: electro-mechanical and electromagnetic. The first ensures control of the mechanical coordinates, while the second controls the rotor (stator) flux for field-oriented control and the determination of its module. Such a decomposition is de facto stan-dard for both indirect and direct field-oriented control, since the control algorithm in this case is the simplest and also transparent from the perspective of the physics of an electric machine’s operation. At the same time, the mechanism for forming the decomposition involves compensating for the internal feedback loops of the induction motor model, which negatively affects the robustness properties of the control system against parametric and coordinate disturbances. An alternative approach is being considered in the field of energy, based on the fact that the electrical part of an induction machine is intrinsically asymptotically stable that is, passive and therefore has a Lyapunov function, which is used to prove its stability. Taking this property into account, an engineering-friendly method is presented for synthesizing a vector control system for the torque and flux linkage vector of an induction motor based on the second Lyapunov method, which forms an alternative decomposition in the form of a mechanical-electrical subsystem. Two new forms of Lyapunov functions have been found for designing field oriented control system the rotor and stator flux vectors. The synthesized control systems ensure asymptotic tracking of the specified trajectories of torque and flux vector magnitude, and have a physically well-founded structure since they preserve the structure of the induction motor model. Ref. 19.