Sensorless Induction Motor Drives Using Adaptive Flux Observer at Low Frequencies

M S Zaky,H A Maksoud,H Z Azazi

doi:10.48084/etasr.1752

M S Zaky, H A Maksoud + Show 1 more

Open Access

https://doi.org/10.48084/etasr.1752

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Abstract

Operation at low frequencies of sensorless drives using machine model-based estimation methods is a challenging issue. This paper proposes an adaptive flux observer (AFO) method of speed estimation for sensorless induction motor drives. The observer feedback gains are designed to guarantee accurate speed estimation, especially at low frequencies in the regenerating mode operation. A complete sensorless IM drive with the proposed AFO is executed in the laboratory. Extensive experimental results under different operating conditions are provided to prove the effectiveness of the proposed AFO, particularly under low stator frequencies in both motoring and regenerating modes of operation.

Highlights

Precise speed information is very important for speed control of Induction Motor (IM) drives
Different speed estimation methods with and without parameters estimations were presented [3,4,5,6,7,8]. These methods can be classified as different estimation methods such as direct speed calculation method, model reference adaptive system method (MRAS) [1], Kalman filter [2], adaptive flux observers (AFO) [3, 6, 7], intelligent control based methods (AI) [5], and sliding mode observer (SMO) [8]
The hardware components include a 1.1 kW IM interfaced with DC generator for load torque applications, PWM inverter with six IGBT's, gate drive and interface circuits, 3-phase full wave rectifier circuit, DSPDS1104 control board, incremental encoder, voltage and

Summary

Introduction

Precise speed information is very important for speed control of Induction Motor (IM) drives. The non-fundamental wave speed estimation methods are a good choice at zero and very low stator frequencies. Fundamental-wave-model-based approaches of speed estimation give good behavior during medium and high frequencies They fail to guarantee the desired performance under very low and zero speeds [2]. Nonfundamental wave speed estimation methods are a good choice at zero and very low stator frequencies [9] Zero voltage vector injection scheme for online flux estimation was presented in [20] These methods have torque ripples and need a special design of the machine

Methods

Results

Conclusion