scholarly journals Sliding Mode Control for Bearingless Induction Motor Based on a Novel Load Torque Observer

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Zebin Yang ◽  
Ling Wan ◽  
Xiaodong Sun ◽  
Lin Chen ◽  
Zheng Chen

For the problem of low control performance of Bearingless Induction Motor (BIM) control system in the presence of large load disturbance, a novel load torque sliding mode observer is proposed on the basis of establishing sliding mode speed control system. The load observer chooses the speed and load torque of the BIM control system as the observed objects, uses the speed error to design the integral sliding mode surface, and adds the low-pass filter to reduce the torque observation error. Meanwhile, the output of the load torque is used as the feedforward compensation for the control system, which can provide the required current for load changes and reduce the adverse influence of disturbance on system performance. Besides, considering that the load changes lead to the varying rotational inertia, the integral identification method is adopted to identify the rotational inertia of BIM, and the rotational inertia can be updated to the load observer in real time. The simulation and experiment results all show that the proposed method can track load torque accurately, improve the ability to resist disturbances, and ameliorate the operation quality of BIM control system. The chattering of sliding mode also is suppressed effectively.

2011 ◽  
Vol 128-129 ◽  
pp. 25-29
Author(s):  
Bo Fan ◽  
Xing Li ◽  
Jie Xin Pu ◽  
Jian Wei Ma ◽  
Ju Wei Zhang

In order to solve the problem of integration saturation drift and hardship in compensation quantity calculation exist in rotor flux observation of induction motor, a rotor flux observer based on nonlinear quadrature double compensation method is presented in this paper. The quantity of compensation is determined dynamically according to the quadrature level between flux and back electromotive force. Through the order change of compensation and low-pass filter, quick response of flux when signal frequency leaps is realized. The simulation result shows that the method can improve the flux waveform, realize the accurate and swift track of flux.


ELKHA ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 54
Author(s):  
Eska Rizqi Naufal ◽  
Gigih Priyandoko ◽  
Fachrudin Hunaini

The 3 phase induction motor is a reliable and strong motor also has cheap price. However induction motor are also vulnerable, from the result of survey conducted by Electric Power Research Institute (EPRI), there are 41% cases of damage occur in the bearing caused by working environment condition, bearing age, and several other factors. Bearing fault is not easily to identified, with applying the data extraction method using the Discrete Wavelet Transform (DWT) and the K-Medoids clustering method will facilitate the identification process. The extraction method will pass the data in the form of current signals into the digital filter (Low Pass Filter and High Pass Filter) to be mapped into the region of frequency and time simultaneously, and clustering method will group data based on certain characteristics. Based on the clustering tests that have been done on the 3 phase induction motor current signal data with 3 bearing conditions, the Discrete Wavelet Transformation with mother wavelet bior1.1 decomposition level 2 and K-Medoids produce an accuracy rate of 86.8%.


Author(s):  
Ali Karami-Mollaee ◽  
Hamed Tirandaz ◽  
Oscar Barambones

Purpose The purpose of this paper is position control scheme for a servo induction motor (SIM) with uncertainty has been designed using a new observer issue and a dynamic sliding mode control (DSMC). Design/methodology/approach In DSMC, the chattering is removed due to the integrator (or a low-pass filter) which is placed before the input control of the plant. However, in DSMC, the augmented system has one dimension bigger than the actual system (if integrator is used) and then, the plant model should be completely known. To solve this problem in SIM, the use of a new adaptive state observer (ASO) is proposed. Findings The advantage of the proposed approach is to maintain the system controlled under the external load torque variations. Then, the load variations do not affect the motor positioning. Moreover, it is demonstrated that the observer error converges to zero based on the Lyapunov stability theory. Originality/value The knowledge of the upper bound for the system uncertainty is not necessary in an adaptive state observer, which is important in practical implementation. Simulation results are presented to demonstrate the performance of the proposed approach.


2020 ◽  
Vol 17 (3) ◽  
pp. 172988142091698 ◽  
Author(s):  
Pengcheng Wang ◽  
Dengfeng Zhang ◽  
Baochun Lu

This article investigates a difficult problem which focuses on the external disturbance and dynamic uncertainty in the process of trajectory tracking. This article presents a robust adaptive fuzzy terminal sliding mode controller with low-pass filter. The low-pass filter can provide smooth position and speed signals. The fuzzy terminal sliding mode controller can achieve fast convergence and desirable tracking precision. Chattering is eliminated with continuous control law, due to high-frequency switching terms contained in the first derivative of actual control signals. Ignoring the prior knowledge upper bound, the controller can reduce the influence of the uncertain kinematics and dynamics in the actual situation. Finally, the experiment is carried out and the results show the performance of the proposed controller.


Author(s):  
Yahya Ahmed Alamri ◽  
Nik Rumzi Nik Idris ◽  
Ibrahim Mohd. Alsofyani ◽  
Tole Sutikno

<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>


2013 ◽  
Vol 307 ◽  
pp. 27-30 ◽  
Author(s):  
Yu Feng Zhang ◽  
Sheng Jin Li ◽  
Yong Zhou ◽  
Qi Xun Zhou

In order to improve the performance of sensorless PMSM control system, an improved sliding mode observer (SMO) is proposed in this paper. To decrease the vibration of SMO, a variable switching gain which changes according to the winding currentn is adopted. To improve the estimated value of rotor position, a extra low pass filter (LPF) is employed and the linear interpolation method is used to calculate compensation value of the phase delay caused by LPF. To verify the performance of proposed SMO, a sensorless field oriented vector control system of PMSM is designed. At last, the performance of the improved SMO and the sensorless PMSM vector control system are verified by experimental results.


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