Model predictive control, especially model predictive current control, has received a great deal of attention in the motor drive field in recent years, due to its ability to render fast dynamic ...response and to handle multiple variables, nonlinearities, and system constraints in an intuitive way. However, the conventional single-vector-based model predictive hysteresis current control brings about some problems, such as high sampling frequency and poor steady-state control performance. In this paper, a novel double-vector-based model predictive hysteresis current control (DV-MPHCC), which utilizes an arbitrary vector and a zero vector to form a voltage vector combination, is proposed. To verify the improved performance over a short predictive horizon, a series of comparisons are conducted between the two control algorithms by simulation and experiment. Both simulation and experiment results validate that the DV-MPHCC proposed has advanced steady-state control performance, and a lower sampling frequency.
The paper presents the relevant topic of improving protection devices for asynchronous engines used in agriculture. We have also provided the data of technical and technological damage. There have ...been identified the main causes of asynchronous motor failure. You may also find a short list of the main existing protection systems for induction motors, the analysis of their shortcomings and prospects for further improvement. We have justified the structural scheme of a universal protective device, which consists of the following channels: a current overload control channel, a rotor seizure channel and a feed line phase failure monitoring channel. We have also given a circuit scheme of the proposed protective device and the description of the circuit operation in the operational mode as well as in various emergency modes. The use of a microcircuit-comparator of the type K554 CA3 (the operational amplifier) as a threshold element with an adjustable threshold voltage value is considered to be an original technical solution.
The article considers the construction of a simulation model of an electrical complex including an asynchronous electric motor with frequency regulation, driving a centrifugal pump. Fluid pumping ...stations based on centrifugal pumps with asynchronous electric drives controlled by frequency converters are widely used, which makes the work relevant. Obtaining the dynamic characteristics of these drives makes it possible to understand the relationship of energy distribution, as well as to coordinate the operating modes of its main parts. For this purpose, a simulation model of the electric drive of the liquid pumping station is developed. This simulation model is used to carry out numerical experiments of the system, which includes the power channel of the electric drive, as well as the control system. Simintech software product is used as a modeling environment. In the work, transient processes of the coordinates of the electric drive are obtained under the influence of both the hydraulic load and the power supply. The influence of the hydraulic resistance of the pressure pipeline and static back pressure on the mechanical characteristic of the moment of resistance of the electric drive as a whole is shown. The considered approach for calculating the characteristics makes it possible to evaluate the mutual influence of the coordinates of various physical nature of centrifugal pump installations with an asynchronous frequency-controlled electric motor on each other.
In the paper dynamic electromechanical interaction between the rotating machine drive system and the electric driving motor is considered. The investigations are performed by means of the circuit ...model of the asynchronous motor as well as using an advanced structural hybrid model of the drive system. Using the analytical solutions applied for the electrical and the mechanical systems the electromagnetic stiffness and coefficient of damping, both generated by the electric motor rotationally interacting with the mechanical system of the given dynamic properties, were determined. By means of experimentally validated computational responses obtained for torsional harmonic excitation induced by the driven machine working tool, a modification of dynamic properties of the mechanical system by the electromagnetic flux between the stator and the rotor has been studied.
•Analytical model of the driven machine–asynchronous motor system.•Attenuation of vibration resonances caused by the electromagnetic damping.•Increase of the mechanical natural frequencies due to electromagnetic stiffening.•Induction of severe low-frequency torsional vibrations by the asynchronous motor.•Estimation of electromechanical coupling severity using dynamic characteristics.
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For the optimal speed-torque control of asynchronous motors for the electric cars in the field-weakening region, a random forest regression (RFR) algorithm is introduced in this article, to solve the ...problem of stator d -axis (<inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sd}}}</tex-math></inline-formula>) and the q -axis current (<inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sq}}}</tex-math></inline-formula>) matching. First, a vector control system for the asynchronous motors is built on the basis of the current distribution output model. Second, according to the limiting conditions of maximum voltage (<inline-formula><tex-math notation="LaTeX">{\boldsymbol{U}_{\boldsymbol{smax}}}</tex-math></inline-formula>) and current (<inline-formula><tex-math notation="LaTeX">{\boldsymbol{I}_{\boldsymbol{smax}}}</tex-math></inline-formula>), an analytical model of the maximum torque output is established, and the current distribution law is analyzed. Third, based on the variation laws of <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sd}}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sq}}}</tex-math></inline-formula>, a closed-loop voltage vector analytical model is designed and embedded in the vector control system to analyze the simulation results. Fourth, an AVL dynamometer experimental platform is built to collect the measured sample data under a constant temperature of 85 °C and maximum power output. The working condition parameters serve as the input of the RFR model, whereas <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sd}}}</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sq}}}</tex-math></inline-formula> are the outputs. The validity of the current distribution is verified. Finally, the regression model is embedded in the vector control system to determine <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sd}}}\,</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">{\boldsymbol{i}_{\boldsymbol{sq}}}</tex-math></inline-formula> under different working conditions. Results verify the correctness and effectiveness of the proposed algorithm.
This article discussed the development of a solar photovoltaic-fed modular multilevel inverter (MMI) with reduced switch count to operate an asynchronous motor drive for maritime applications. The ...proposed marine water-pumping system consist of a PV panel, an asynchronous motor drive, and modular inverter. The suggested topology can produce 11 levels of output using asymmetric DC sources. The proposed MMI consists of five DC sources, and they are powered by the PV panels. The primary advantage of the proposed topology is that it does not need any auxiliary circuit to produce the negative levels. Moreover, the active sources (PV panels) in the proposed system are reduced by implementing a modified single-input and multiple-output SEPIC converter. The power consumption by on-board pumping systems in maritime is estimated to be almost 50% of the total power. Taking this into account, this article investigates an adaptive fuzzy logic-based closed-loop control design for reducing the losses in the induction machine and thereby improving the efficiency of the system. Further, the performance of the proposed system is compared with the conventional PI controller, and from the results, it is proved that the proposed control system works effectively in reducing the losses as well as improving the efficiency of the system. The simulations are carried out in MATLAB/Simulink, and the experimental investigations are carried out in the laboratory. The obtained experimental results are similar to the simulation results.
In this article, the coupling effects of the unbalanced magnetic pull and ball bearing on nonlinear vibration of the three-phase asynchronous motor are investigated with the experimental and ...numerical methods. A test rig of a motor whose rotor supported by ball bearings is used and a 2 degrees of freedom magnetic solid coupling dynamic model of the motor rotor system is presented. The nonlinear dynamic response and spectrum are obtained from experiments and numerical analysis. The numerical results are in good agreement with test data, thus validating the presented model. It is found that the unbalanced magnetic pull and ball bearing forces possess the significantly interactional and nonlinear influences on the rotor dynamic characteristics. Small magnetic pull could impact the nonlinear bearing-rotor system, resulting in remarkable changes in the dynamic characteristics of the system. The effects of rotational speed and the rotor mass eccentricity on dynamic behaviors of the motor are discussed, and the results show that the magnetic pull gradually increases the amplitude of the ball bearing-rotor system, and its effect decreases with the increment of the rotational speed and mass eccentricity.
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Modern industrial processes make extensive use of electric induction motors; timely fault diagnosis of such equipment is a critical phase that allows planning effective predictive maintenance which ...can significantly reduce downtime and optimize productivity. In this study, we present a novel technique for the diagnosis of both simple mechanical and electrical defects as well as their combination in an asynchronous motor based on current signal measurements using various operating states. The suggested technique implements the fault detection mechanism by mapping stator signals recorded from a three-phase induction motor in a steady state. These signals are used to indicate a healthy condition as well as failed states, which are mapped onto a 3D point cloud using a voxelization approach. The use of this data structure aids in the generation of rich features that keep intact the spatial relationship between the three stator currents, which is then utilized to train a 3D convolutional neural network with the produced voxels (3D CNN). The proposed method surpasses the classical deep learning diagnosis-based method by projecting the stator currents into 2D RGB images because our method prevents data collapsing. The suggested technique for real-time monitoring of the operational state of an induction motor is resilient and fast, according to experimental results acquired by utilizing data from a real test bed.
Operation at low speed and high torque can lead to the generation of strong ripples in the speed, which can deteriorate the system. To reduce the speed oscillations when operating a five-phase ...asynchronous motor at low speed, in this article, we propose a control method based on Gray Wolf optimization (GWO) algorithms to adjust the parameters of proportional–integral (PI) controllers. Proportional–integral controllers are commonly used in control systems to regulate the speed and current of a motor. The controller parameters, such as the integral gain and proportional gain, can be adjusted to improve the control performance. Specifically, reducing the integral gain can help reduce the oscillations at low speeds. The proportional–integral controller is insensitive to parametric variations; however, when we employ a GWO optimization strategy based on PI controller parameters, and when we choose gains wisely, the system becomes more reliable. The obtained results show that the hybrid control of the five-phase induction motor (IM) offers high performance in the permanent and transient states. In addition, with this proposed strategy controller, disturbances do not affect motor performance.
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