Speed Sensorless Vector Control Method Research Articles

An enhanced sensorless control based on active disturbance rejection controller for a PMSM system: design and hardware implementation

PurposeThis paper mainly aims to deal with the problems of uncertainties including modelling errors, unknown dynamics and disturbances caused by load mutation in control of permanent magnet synchronous motor (PMSM).Design/methodology/approachThis paper proposes an enhanced speed sensorless vector control method based on an active disturbance rejection controller (ADRC) for a PMSM. First, a state space model of the PMSM is obtained for the field orientation control strategy. Second, a sliding mode observer (SMO) based on back electromotive force (EMF) is introduced to replace the encode to estimate the rotor flux position angle and speed. Third, an infinite impulse response (IIR) filter is introduced to eliminate high frequency noise mixed in the output of the sliding mode observer. In addition, a speed control method based on an extended state observer (ESO) is proposed to estimate and compensate for the total disturbances. Finally, an experimental set-up is built to verify the effectiveness and superiority of the proposed ADRC-based control method.FindingsThe comparative experimental results show that the proposed speed sensorless control method with the IIR filter can achieve excellent robustness and speed tracking performance for PMSM system.Research limitations/implicationsAn enhanced sensorless control method based on active disturbance rejection controller is designed to realize high precision control of the PMSM; the IIR filter is used to attenuate the chattering problem of traditional SMO; this method simplifies the system and saves the total cost due to the speed sensorless technology.Practical implicationsThe use of sensorless can reduce costs and be more beneficial to actual industrial application.Originality/valueThe proposed enhanced speed sensorless vector control method based on an ADRC with the IIR filter enriches the control method of PMSM. It can ameliorate system robustness and achieve excellent speed tracking performance.

The full-order state observer speed-sensorless vector control based on parameters identification for induction motor

During the operation of speed-sensorless control system for induction motor, the stator and rotor resistance varies greatly with the change of temperature and the frequency of the rotor side, which affects the estimation of the stator flux and leads to the low accuracy of the speed estimation. A speed-sensorless vector control method based on parameters identification with the full-order adaptive state observer is proposed in this paper. In the model reference adaptive system of AC motor, the stator resistance and rotor flux are assigned as state variables to build the reference model, and a full-order flux observer is introduced to adjustable model. Lyapunov theory and Popov superstability theory are used to deduce the speed and rotor resistance adaptive rate. The feedback gain matrix is simplified to speed up the convergence rate of the system. The estimation values of speed and rotor resistance are taken as the proportional integral form, so that an interactive model reference adaptive system is constructed by speed and rotor resistance identification. While observing the rotor flux, it can not only ensure the accuracy of the reference model but also eliminate the disadvantages of the voltage model with integral terms, and the rotor speed can be estimated at the same time. The experimental results show that the accurate performance of speed and flux identification can meet the requirements of application; the proposed control method with the identification of speed and rotor resistance has little fluctuations phenomenon on motor torque in low speed and achieves better performance.

Speed Sensorless Vector Control Based on Full-order Adaptive Observer for Induction Motor Drives at Low Speed

This paper presented a speed sensorless vector control method based on adaptive full-order state observer for induction motor. The rotor speed estimated by an adaptive full-order observer is fed back to the vector control system as a feedback signal to form a closed-loop control of speed. In addition, the stator resistance is also recognized and updated in real time, so the effect of change of stator resistance on accuracy of speed estimation can be eliminated. The parameter identification system is achieved according to the Popov’s hyperstability theory, therefore the system is stable enough even at very low speed. The simulation and experimental results illustrated the correctness and effectiveness of the presented control algorithm.

Single Inverter Fed Speed Sensorless Vector Control of Parallel Connected Two Motor Drive

This paper describes a speed sensorless vector control method of the torque for cost-effective parallel-connected dual induction motor fed by a single inverter. A natural observer with load torque adaptation is employed to estimate the speeds of the same rating induction motors connected in parallel and fed by a single inverter. The speed difference between the two induction motors for unbalanced load conditions is less in natural observer than the conventional adaptive rotor flux observer. Direct field oriented control is used to calculate the rotor angle from the estimated rotor fluxes and the mean rotor flux is kept constant by rotor flux feedback control. The simulation and experimental results of studies are demonstrated for various running conditions to prove the effectiveness of the proposed method. The closed loop speed control operation with inner current control was performed by TMS320F2812 processor.

Characteristics of Speed Sensorless Vector Controlled Induction Motor with High Efficiency Taking Core Loss into Account

This paper presents the characteristics of a speed sensorless vector control method of an induction motor operating at high efficiency and high response, in which core loss is taken into account. An improved method of speed estimation that operates on the principle of speed adaptive flux and current observer has been proposed. An observer is basically an estimator that uses a plant model and a feedback loop with measured stator voltage and current. Simulation results show that the proposed direct field oriented control with the proposed observer provides good performance characteristics. The IM is fed by an indirect power electronics converter. This indirect converter is controlled by a pulse width modulation PWM technique that enables minimization of harmonics introduced by the line converter, as well as the control of the power factor and DC-link voltage. We study the robustness of the overall system- using simulation of different modes to operating modes and varied parameters.

Single Inverter Fed Speed Sensorless Vector Control of Parallel Connected Two Motor Drive

This paper describes a speed sensorless vector control method of the torque for cost-effective parallel-connected dual induction motor fed by a single inverter. A natural observer with load torque adaptation is employed to estimate the speeds of the same rating induction motors connected in parallel and fed by a single inverter. The speed difference between the two induction motors for unbalanced load conditions is less in natural observer than the conventional adaptive rotor flux observer. Direct field oriented control is used to calculate the rotor angle from the estimated rotor fluxes and the mean rotor flux is kept constant by rotor flux feedback control. The simulation and experimental results of studies are demonstrated for various running conditions to prove the effectiveness of the proposed method. The closed loop speed control operation with inner current control was performed by TMS320F2812 processor.

Speed -Sensorless Vector Control of Parallel Connected Induction Motor Drive Fed by a Single Inverter using Natural Observer

This paper describes the speed sensorless vector control method of the parallel connected induction motor drive fed by a single inverter. Speed and rotor fluxes of the induction motor are estimated by natural observer with load torque adaptation and adaptive rotor flux observer. The performance parameters speed and rotor fluxes are estimated from the measured terminal voltages and currents. Fourth order induction motor model is used and speed is considered as a parameter. The performance of the natural observer is similar to the conventional observer. The speed of an induction motor is estimated by MATLAB simulation under different speed and load conditions. Estimated values along with other measured states are used for closed loop control. The simulation results show that the natural observer is also effective for parallel connected induction motor drive.

Sensorless Vector Control of an Induction Motor Fed by a PWM Inverter Through an Output LC Filter

The paper presents a speed sensorless vector control method for an induction motor that is supplied by a PWM inverter through an output LC filter. The system states are estimated by an adaptive full-order observer, and no additional voltage, current or speed measurements are needed. The rotor speed adaptation is based on the estimation error of the inverter output current. Quasi-steady-state analysis is used to illustrate the speed adaptation, and the stability is analyzed using a linearized model. Simulation and experimental results show that it is possible to achieve performance comparable to that of a drive without the LC filter.

A speed-sensorless vector control method of parallel-connected dual induction motor fed by a single inverter

The purpose of this paper is to present the speed-sensorless vector control method of the torque production from each rotor of two induction motors with parallel-connected stator windings fed by a single inverter. In this paper, an adaptive rotor flux observer is applied to the method in order to eliminate a flux sensor, and an adaptive scheme for rotor speed is added to the adaptive rotor flux observer in order to eliminate a speed sensor. The experimental results show that the proposed method is useful under the condition that the ratings of each induction motor are different.

High Efficiency Control Method of Speed-Sensorless Vector Controlled Induction Motor Taking Core Loss into Consideration

This paper proposes a speed-sensorless vector control method for an induction motor operating at high efficiency and high response, in which core loss is taken into account, and discusses the system's performance. The proposed vector control system consists of a speed-adaptive rotor-flux observer which takes core loss into account and employs a direct-field-oriented control scheme which compensates for the influence of core loss. On the basis of simulation and experimental results, we show that the proposed system can estimate motor speed even when the rotor flux is changed.

A speed-sensorless vector control of induction motor operating at high efficiency taking core loss into account

This paper proposes a speed-sensorless vector control method for an induction motor operating at high efficiency and high response, in which core loss is taken into account, and discusses the system's performance. The proposed vector control system consists of a speed-adaptive rotor-flux observer which takes core loss into account and employs a direct-field-oriented control scheme which compensates for the influence of core loss. On the basis of simulation and experimental results, we show that the proposed system can estimate motor speed even when the rotor flux is changed.

Speed Sensorless Vector Control Method of Induction Motor Including A Low Speed Region

In the recent years, many speed sensorless control method with adaptive observer of induction motor have been developed. The feedback gain of observer is designed from the responsive viewpoint of the error convergence. When we drive induction motor in the low speed region with each method, the control characteristic is deteriorated. In this paper, we give the design of the speed sensorless adaptive flux observer in the low speed region and propose speed sensorless vector control system with it from the stable viewpoint of the error convergence. And we show experimental results of this method.

Speed Sensorless Vector Control Method for an Industrial Drive System.

We propose a novel speed sensorless vector control method for induction motors, which is applicable to industrial drive systems.This method calculates the flux axis angular velocity and rotor speed of an induction motor from the induced voltages, without using any delay components. According to this method, the system can directly estimate an accurate motor speed, and precisely generate torque.In addition, this system can smoothly restart operation after an instantaneous power interruption.We show the validity of the proposed control method through several experiments.