A globally exponentially stable position observer for interior permanent magnet synchronous motors

The design of a position observer for the interior permanent magnet synchronous motor is a challenging problem that, in spite of many research efforts, remained open for a long time. In this paper we present the first globally exponentially convergent solution to it, assuming that the saliency is not too large. As expected in all observer tasks, a persistency of excitation condition is imposed. Conditions on the operation of the motor, under which it is verified, are given. In particular, it is shown that at rotor standstill---when the system is not observable---it is possible to inject a probing signal to enforce the persistent excitation condition. {The high performance of the proposed observer, in standstill and high speed regions, is verified by extensive series of test-runs on an experimental setup

Integral high order sliding mode control of single-phase induction motor

An observer-based controller for the single-phase induction motor is proposed in this paper. The scheme presented is formulated using block control feedback linearization technique and high order sliding mode algorithms with measurements of the rotor speed and stator currents. A second order sliding mode observer is included into the controller design in order to obtain estimates of the rotor flux. The stability of the complete closed-loop system is analyzed in the presence of model uncertainty, namely, rotor resistance variation and bounded time-varying load torque.Cinvesta

A Globally Convergent Adaptive Indirect Field-Oriented Torque Controller for Induction Motors

International audienceOne of the most challenging problems in AC drives applications is the design of a simple plug-in adaptation scheme to estimate the unknown rotor resistance and load torque for the industry-standard indirect field oriented control. In this paper we give the first globally convergent solution to this problem for torque control of current-fed induction motors that does not rely on any excitation assumption. Some results on speed regulation are also presented

A robust sensorless output feedback controller of the induction motor drives: New design and experimental validation

International audienceIn this paper, a sensorless output feedback controller is designed in order to drive the Induction Motor IM without the use of flux and speed sensors. Firstly, an observer that uses only the measured stator currents is synthesized to estimate the mechanical variables (speed and load torque) and the magnetic variables (fluxes) by structurally taking into account the unobservability phenomena of the Sensorless IM (SIM) and the parametric uncertainties. Secondly, a current-based field oriented sliding mode control, that uses the flux and the speed estimates given by the former observer is developed so as to steer the estimated speed and flux magnitude to the desired references. Since the observer design is independent of the control and depends on theIM parametric uncertainties, a separation principle is introduced to guarantee the practical stability of the whole closed-loop system "observer -controller" ("O-C") according to observability and unobservability time variation. A significant benchmark taking into account the unobservability phenomena of the \textit{SIM} is presented to show the performances of the whole control scheme against experimental set-up

High-Order Sliding Mode Block Control of Single-Phase Induction Motor

A new sliding mode (SM) observer-based controller for single-phase induction motor is designed. The proposed control scheme is formulated using block control feedback linearization technique and high-order SM algorithms with measurements of the rotor speed and stator currents. The stability of the complete closed-loop system, including the rotor flux second-order SM observer, is analyzed in the presence of model uncertainty, namely, rotor resistance variation and bounded timevarying load torque.CINVESTA

A Hybrid Sensorless Observer for the Robust Global Asymptotic Flux Reconstruction of Permanent Magnet Synchronous Machines

We propose a hybrid sensorless observer for permanent magnet synchronous machines with global asymptotic stability guarantees. Exploiting the constraint of the rotor flux on a circle of unknown radius, we design an integrator system with periodic jumps triggered by a clock to generate a linear regression containing the flux estimation error. Then, a normalized projected gradient descent identifier provides the observer estimates. For the closed-loop system, it is shown that there exists a robustly globally asymptotically stable compact attractor, which, additionally, ensures zero estimation error if appropriate Persistency of Excitation (PE) conditions are satisfied. In this respect, sufficient conditions ensuring PE are provided for the angular speed and the clock period