Adaptive Interconnected Observer Research Articles

Sensorless control scheme based on sliding modes for interior permanent magnet synchronous motor

In this article, a sensorless speed control design for the interior permanent magnet synchronous motor based on sliding mode approach is proposed. The control objective is to drive the rotor speed to desired reference despite load torque disturbances and parameter uncertainties. The proposed control strategy combines a Sliding Mode Controller with an Adaptive Interconnected Observer design based on sliding mode techniques, which allows to estimate the rotor speed, the stator resistance and the load torque. Furthermore, experimental results, including a comparative study against schemes from literature, illustrate the robustness and performance of proposed approach.

Online Capacity Estimation for Lithium-Ion Battery Cells via an Electrochemical Model-Based Adaptive Interconnected Observer

Battery aging is a natural process that contributes to capacity and power fade, resulting in a gradual performance degradation over time and usage. State-of-charge (SOC) and state-of-health (SOH) monitoring of an aging battery poses a challenging task to the battery management system (BMS) due to the lack of direct measurements. Estimation algorithms based on an electrochemical model that considers the impact of aging on physical battery parameters can provide accurate information on lithium concentration and cell capacity over a battery's usable lifespan. A temperature-dependent electrochemical model, the enhanced single particle model (ESPM), forms the basis for the synthesis of an adaptive interconnected observer that exploits the relationship between capacity and power fade, due to the growth of solid electrolyte interphase layer (SEI), to enable combined estimation of states (lithium concentration in both electrodes and cell capacity) and aging-sensitive transport parameters (anode diffusion coefficient and SEI layer ionic conductivity). The practical stability conditions for the adaptive observer are derived using Lyapunov's theory. Validation results against experimental data show a bounded capacity estimation error within 2% of its true value. Furthermore, the effectiveness of capacity estimation is tested for two cells at different stages of aging. Robustness of capacity estimates under measurement noise and sensor bias is studied.

Robust adaptive high order sliding-mode optimum controller for sensorless interior permanent magnet synchronous motors

In this paper, a robust nonlinear controller for sensorless interior permanent magnet synchronous motors (IPMSM) is designed to track a desired reference which is computed by using a maximum-torque-per-ampere strategy (MTPA). The proposed controller ensures finite-time convergence of sliding variables despite parameter uncertainties and unknown load torque. Furthermore, from the measurement of the currents and the voltages, a new analysis of the observability property is developed. Then, an adaptive interconnected observer is designed to estimate the angular velocity, the position, the load torque and the stator resistance. Using a Lyapunov approach, an analysis of the closed-loop system stability is given. Simulation results are presented to confirm the effectiveness of the proposed method.

Adaptive interconnected observer-based sensorless non-linear generalised predictive control for IMs with parameters tuning

The combination of the non-linear generalised predictive control (NGPC) and the adaptive interconnected observer (AIO) is considered for the design of the output feedback predictive controller. Since the induction motors (IMs) are intensively used in applications requiring high dynamic performance, the algorithm developed is potentially useful for a fully decoupling in speed and flux magnitude regulation. Indeed, in a first step the state-feedback controller is given, which stems from the approximation of the output tracking error in the receding horizon by its Taylor-series expansion is given. In a second step, the AIO property is exploited in order to avoid the problem of parameters uncertainly and state unavailability during the drive motor, with realising a suitable tracking of trajectories for the system output. This results in a sensorless control of the induction motors, whose rotor and stator resistances, the load torque, the rotor flux and mechanical speed are simultaneously recovered by profiting only from the measurements of the stator current. Effectiveness of the proposed observers and the performance of the controller are confirmed by simulation results.

An Adaptive Interconnected Observer for Sensorless Control of PM Synchronous Motors With Online Parameter Identification

This paper proposes an adaptive interconnected observer for sensorless control of a synchronous motor. The corresponding observer is used to estimate the rotor speed, the rotor position, and the load torque and, moreover, to estimate the stator inductance and the stator resistance. The convergence of the observer estimation error is analyzed, and sufficient conditions are given to prove the practical stability. Experimental results are shown to confirm the effectiveness of the proposed method.

Adaptive interconnected observer-based backstepping control design for sensorless induction motor

In this paper, an observer-based controller scheme is designed to robustly drive a sensorless Induction Motor (IM) even for the case of low frequencies with unknown load torque. Combining the field oriented control strategy with the backstepping control method, we introduce additional integral terms to improve the robustness properties of the controller in spite of uncertainties and perturbations. The estimation of the fluxes, the speed, the load torque and moreover the stator resistance is given by an adaptive interconnected observer. The practical stability of the proposed observer–controller scheme is proved. Finally, some experimental test results are given on the framework of a specific sensorless induction motor benchmark.

Robust integral backstepping control for sensorless IPM synchronous motor controller

In this paper, a sensorless speed control for interior permanent magnet synchronous motors (IPMSM) is designed by combining a robust backstepping controller with integral actions and an adaptive interconnected observer. The IPMSM control design generally requires rotor position measurement. Then, to eliminate this sensor, an adaptive interconnected observer is designed to estimate the rotor position and the speed. Moreover, a robust nonlinear control based on the backstepping algorithm is designed where an integral action is introduced in order to improve the robust properties of the controller. The stability of the closed-loop system with the observer–controller scheme is analyzed and sufficient conditions are given to prove the practical stability. Simulation results are shown to illustrate the performance of the proposed scheme under parametric uncertainties and low speed. Furthermore, the proposed integral backstepping control is compared with the classical backstepping controller.

Optimum torque sensorless HOSM controller for IPMSM via adaptive interconnected observer

In this paper, a nonlinear high order sliding mode (HOSM) controller and an adaptive interconnected observer for sensorless interior permanent magnet synchronous motors (IPMSM) are designed. A maximum-torque-per-ampere strategy (MTPA) is used to compute direct rotor current reference. The high order sliding mode controller is designed in order to ensure finite-time convergence of sliding variables and its high order time derivatives despite parameter uncertainties and unknown load torque. The adaptive interconnected observer estimates the currents, the angular velocity, the position, the load torque and the stator resistance. By Lyapunov theory, the observer-controller stability is proved. Simulation results confirm the effectiveness of the proposed method.

Sensorless speed control of PMSM via adaptive interconnected observer

In this article, a robust sensorless speed observer–controller scheme for a surface permanent magnet synchronous motor (PMSM) is proposed. First-of-all, following preliminary results in the framework of the induction motor that is less sensible to the position estimation error, an adaptive high gain interconnected observer is designed. It is only supplied by the electrical measurement: the motor currents and voltages. This observer estimates the rotor speed and position, the stator resistance and the load torque. A nonlinear backstepping controller is developed. The above observer is associated with this controller and the complete scheme practical stability proof is given. The overall system is tested by simulation in the framework of an industrial benchmark with a trajectory that particularly checks the motor unobservability condition. Some robustness tests have been carried out. The controller–observer scheme shows good performances in spite of the uncertainties and the unknown load torque.

Sensorless induction motor adaptive observer-backstepping controller: experimental robustness tests on low frequencies benchmark

In this study, experimental tests for an observer-based controller scheme are given to drive a sensorless Induction Motor (IM) even for the low frequencies case. Combining the advantages of a field oriented controller with the backstepping control method, a new robust controller is designed to track low frequencies trajectories. The static errors are eliminated using an integral backstepping technique, improving the robustness properties of the controller in spite of the uncertainties and the perturbations. An adaptive interconnected observer is designed for estimating fluxes, speed, load torque and the stator resistance in order to implement the controller. The knowledge of the stator parameter is crucial for sensorless control in particular to track low-speed trajectories when the observability property is lost. Practical stability based on Lyapunov theory has been proved to guarantee the strongly uniformly practical stability of the closed-loop system using the proposed observer–controller scheme. The tests are completed thanks to the reference trajectories of a specific sensorless IM benchmark where the robustness properties are validated under parameter variations and in presence of disturbances even for the low frequencies case.

Adaptive interconnected observer for sensorless induction motor

An adaptive interconnected observer for induction motor (IM) drive without mechanical sensors (speed sensor and load torque sensor) is presented. The observer estimates the fluxes, the angular velocity, the load torque and the stator resistance even under or near unobservable conditions. Practical stability based on Lyapunov theory is proved to guarantee the strongly uniformly practical stability of the estimation error dynamics. A contribution of this article is the experimental validation of the observer on reference trajectories of a sensorless IM observer benchmark. The trajectories of this benchmark are chosen to test the motor near and under conditions of unobservability. Robustness with respect to parameters variations is proved and experimentally verified.

Sensorless Induction Motor: High-Order Sliding-Mode Controller and Adaptive Interconnected Observer

An adaptive interconnected observer and high-order sliding-mode control of induction motors without mechanical sensors (speed sensor and load torque sensor) are proposed and experimentally evaluated. The adaptive interconnected observer estimates fluxes, angular velocity, load torque, and stator resistance. Stability based on Lyapunov theory is proved to guarantee the ldquoobserver-controllerrdquo stability.

High order sliding mode control of a sensorless induction motor

Abstract A new High Order Sliding Mode (HOSM) controller and an adaptive observer for sensorless induction motors (IM) drive are designed. The adaptive interconnected observer estimates the fluxes, the angular velocity, the load torque, and the stator resistance. The speed-flux control law is an original HOSM one: a sliding manifold is designed in order to ensure finite-time convergence of sliding variable and its high order time derivatives. The Lyapunov theory is used to prove the stability of the observer then the stability of the “observer-controller”. To test the feasbility of the proposed solutions, a significant low frequency benchmark is used by considering the sensorless control problem of IM. Robustness with respect to parameters variations is proved and experimentally verified.