Comparison of Estimated Torques Using Low Pass Filter and Extended Kalman Filter for Induction Motor Drives

2015 ◽  
Vol 6 (1) ◽  
pp. 92
Author(s):  
Ibrahim Mohd Alsofyani ◽  
Nik Rumzi Nik Idris ◽  
Yahya A. Alamri ◽  
Tole Sutikno ◽  
Aree Wangsupphaphol ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Nonlinear Models ◽  
Motor Drives ◽  
Computational Time ◽  
Induction Motor Drives ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Calculation Process ◽  
Low Pass

<span lang="EN-US">Torque calculation process is one of the major concerns for controlling induction motors in industry, which requires very accurate state estimation of unmeasurable variables of nonlinear models. This can be solved if the variables used for torque calculation is accurately estimated.  This paper presents a torque calculation based on a voltage model represented with a low-pass filter (LPF), and an extended Kalman filter (EKF). The experimental results showed that the estimated torque at low speed based on EKF is more accurate in the expense of more complicated and larger computational time. </span>

Sensor fault detection, isolation and system reconfiguration based on extended Kalman filter for induction motor drives

2013 ◽  
Vol 7 (7) ◽  
pp. 607-617 ◽  
Author(s):  
Xinan Zhang ◽  
Gilbert Foo ◽  
Mahinda Don Vilathgamuwa ◽  
King Jet Tseng ◽  
Bikramjit Singh Bhangu ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Fault Detection ◽  
Induction Motor ◽  
Extended Kalman Filter ◽  
Motor Drives ◽  
Sensor Fault ◽  
Induction Motor Drives ◽  
System Reconfiguration ◽  
Sensor Fault Detection

Improved Stator Flux Estimation for Direct Torque Control of Induction Motor Drives

2016 ◽  
Vol 7 (4) ◽  
pp. 1049
Author(s):  
Yahya Ahmed Alamri ◽  
Nik Rumzi Nik Idris ◽  
Ibrahim Mohd. Alsofyani ◽  
Tole Sutikno
Keyword(s):  
Induction Motor ◽  
Cutoff Frequency ◽  
Direct Torque Control ◽  
Motor Drives ◽  
Torque Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Flux Estimation ◽  
Stator Flux

<p>Stator flux estimation using voltage model is basically the integration of the induced stator back electromotive force (emf) signal. In practical implementation the pure integration is replaced by a low pass filter to avoid the DC drift and saturation problems at the integrator output because of the initial condition error and the inevitable DC components in the back emf signal. However, the low pass filter introduces errors in the estimated stator flux which are significant at frequencies near or lower than the cutoff frequency. Also the DC components in the back emf signal are amplified at the low pass filter output by a factor equals to . Therefore, different integration algorithms have been proposed to improve the stator flux estimation at steady state and transient conditions. In this paper a new algorithm for stator flux estimation is proposed for direct torque control (DTC) of induction motor drives. The proposed algorithm is composed of a second order high pass filter and an integrator which can effectively eliminates the effect of the error initial condition and the DC components. The amplitude and phase errors compensation algorithm is selected such that the steady state frequency response amplitude and phase angle are equivalent to that of the pure integrator and the multiplication and division by stator frequency are avoided. Also the cutoff frequency selection is improved; even small value can filter out the DC components in the back emf signal. The simulation results show the improved performance of the induction motor direct torque control drive with the proposed stator flux estimation algorithm. The simulation results are verified by the experimental results.</p>

Parietal Representation of Hand Velocity in a Copy Task

2005 ◽  
Vol 93 (1) ◽  
pp. 508-518 ◽  
Author(s):  
Bruno B. Averbeck ◽  
Matthew V. Chafee ◽  
David A. Crowe ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Transfer Function ◽  
Linear Model ◽  
Parietal Cortex ◽  
Neural Activity ◽  
Nonlinear Models ◽  
Linear Representation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Width ◽  
Low Pass

We recorded neural activity from ensembles of neurons in areas 5 and 2 of parietal cortex, while two monkeys copied triangles, squares, trapezoids, and inverted triangles and used both linear and nonlinear models to predict the hand velocity from the neural activity of the ensembles. The linear model generally outperformed the nonlinear model, suggesting a reasonably linear relation between the neural activity and the hand velocity. We also found that the average transfer function of the linear model fit to individual cells was a low-pass filter because the neural response had considerable high-frequency power, whereas the hand velocity only had power at frequencies below ∼5 Hz. Increasing the width of the transfer function, up to a width of 700–800 ms, improved the fit of the model. Furthermore, the Rsqr of the linear model improved monotonically with the number of cells in the ensemble, saturating at 60–80% for a filter width of 700 ms. Finally, it was found that including an interaction term, which allowed the transfer function to shift with the eye position, did not improve the fit of the model. Thus ensemble neural responses in superior parietal cortex provide a high-fidelity, linear representation of hand kinematics within our task.

Motion Estimation Using Point Cluster Method and Kalman Filter

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
M. Senesh ◽  
A. Wolf
Keyword(s):  
Kalman Filter ◽  
Rigid Body ◽  
Rigid Body Motion ◽  
Body Motion ◽  
Cluster Method ◽  
Pass Filter ◽  
Low Pass Filter ◽  
The Real ◽  
Low Pass ◽  
Instantaneous Frequencies

The most frequently used method in a three dimensional human gait analysis involves placing markers on the skin of the analyzed segment. This introduces a significant artifact, which strongly influences the bone position and orientation and joint kinematic estimates. In this study, we tested and evaluated the effect of adding a Kalman filter procedure to the previously reported point cluster technique (PCT) in the estimation of a rigid body motion. We demonstrated the procedures by motion analysis of a compound planar pendulum from indirect opto-electronic measurements of markers attached to an elastic appendage that is restrained to slide along the rigid body long axis. The elastic frequency is close to the pendulum frequency, as in the biomechanical problem, where the soft tissue frequency content is similar to the actual movement of the bones. Comparison of the real pendulum angle to that obtained by several estimation procedures—PCT, Kalman filter followed by PCT, and low pass filter followed by PCT—enables evaluation of the accuracy of the procedures. When comparing the maximal amplitude, no effect was noted by adding the Kalman filter; however, a closer look at the signal revealed that the estimated angle based only on the PCT method was very noisy with fluctuation, while the estimated angle based on the Kalman filter followed by the PCT was a smooth signal. It was also noted that the instantaneous frequencies obtained from the estimated angle based on the PCT method is more dispersed than those obtained from the estimated angle based on Kalman filter followed by the PCT method. Addition of a Kalman filter to the PCT method in the estimation procedure of rigid body motion results in a smoother signal that better represents the real motion, with less signal distortion than when using a digital low pass filter. Furthermore, it can be concluded that adding a Kalman filter to the PCT procedure substantially reduces the dispersion of the maximal and minimal instantaneous frequencies.

Harmonic Analysis of a Single Phase Modulated Inverter

2016 ◽  
Vol 2 (3) ◽  
pp. 607 ◽  
Author(s):  
Md. Imran Azim ◽  
S. M. Mohiuddin
Keyword(s):  
Communication Networks ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Motor Drives ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Electric Motor Drives ◽  
Output Terminal ◽  
Low Pass ◽  
Torque Pulsations

<p>This paper portrays an approach of an analysis that provides information regarding the presence of harmonics at the inverter output terminal. It is certainly true that harmonics cause unbalance and excessive neutral currents, interference in nearby communication networks and disturbance to other consumers. More importantly, torque pulsations in electric motor drives are caused by them. Thus, the minimization of the harmonics contained in the output of a single phase current controlled inverter undergoing hysteresis modulation technique is important so as to get rid of these detrimental effects. A model of an LC low pass filter has been provided in this paper for harmonics reduction purpose, as it blocks the harmonics and passes approximately a sinusoidal output. Moreover, the paper contains the method of Fast Fourier Transform (FFT) for fulfilling the desire of understanding not only the fundamental component but also the harmonics component flawlessly. It has been found from the simulation that the Total Harmonic Distortion (THD) in ideal case is 0%. On the other contrary, during the presence of harmonics, it steeps to 41.415% that can be mitigated to 0.0092% by implementing an LC low pass filter in a precise manner.</p>

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