Advanced control of induction motors

摘要: The current industrial standard for the control of induction motor is so called vector (VC) or field-orientated (FOC) which transforms and controls as a direct (DC) motor. Besides its many advantages, such fast decoupled dynamics speed flux, it well known that VC depends on detailed system model very sensitive to parameter uncertainties external disturbance (load torque). To clarify further only partial feedback linearising can achieve decoupling flux asymptotically. coupling still exists when not kept in constant, i.e. weakened order operate at higher keep input voltage within saturation limits, adjusted maximize power efficiency with light load. thesis will summarise research advanced approaches motors Chapter One. Two starts building fifth-order nonlinear dynamic an then recalls principal traditional motors. differential-geometric technique based has developed motors, convert some intractable problems into simpler by familiar linear methods. conventional been investigated via linearisation (FLC) first. Then input-output applied to design fully flux. remove weak robustness requirement accurate FLC, novel adaptive designed perturbation estimation. be represented two coupled interconnected subsystems: rotor subsystem subsystem, respectively. System terms are defined include lumped term nonlinearities, uncertainties, interactions between subsystems fictitious state equations. perturbations estimated designing observers employed cancel real perturbations, assumed all internal states measured. doesn’t require algorithm. It decouple regulation handle time-varying uncertainties. estimations deal unknown constant parameters suitable handling functional uncertainties. Nonlinear output measurements addressed Five, assuming stator volatge/currents measurable. A sliding mode observer current. Moreover, third-order estimate unmeasured perturbation, flux. Simulation studies have carried out verifying effectiveness proposed controllers compared FLC.