Motor Flux Research Articles

COMPARATIVE AND PERFORMANCE ANALYSIS OF INDUCTION MOTOR WITH ANN CONTROLLER

A novel design of an adaptive artificial neural network technique (ANN) for controlling of the essential parameters, like as speed, torque, flux, voltage, current, and power etc of the induction motor is presented in this paper. Induction motors are characterized by way of incredibly non-linear, complicated and time-various dynamics and inaccessibility of its states and outputs for measurements. Thus it can be considered as a challenging engineering difficulty in the industrial sector. A few of them, such as PI, fuzzy strategies, Fuzzy logic based controllers are regarded as capability candidates for such application for operating induction motor. Hence of which, the outcome of the controller is also random and high-rated results are probably not obtained. Resolution of the proper rule base application upon the drawback can be achieved by the use of an ANN controller, which becomes a built-in system of method for the manipulate purposes and yields results, which is the focus of this paper. Within the designed ANN scheme, neural community tactics are used to prefer an appropriate rule base, which is utilizing the back propagation algorithm. The simulation outcome provided on this paper is exhibit the effectiveness of the developed approach, which has acquired faster response time or settling times. Additionally, the procedure developed has got a huge number of benefits within the industrial sector will also be converted into a real time application making use of some interfacing cards.

Switching losses minimization by using direct torque control of induction motor

Direct torque control is becoming the industrial standards for induction motor torque control. This paper presents switching loss minimization technique of improved direct torque control (DTC) of induction motor. Direct torque control (DTC) of an induction motor supplied by a voltage source inverter is a simple scheme that does not need long computation time, can be implanted without speed sensors and is insensitive to parameter variations. In principle, the motor terminal voltages and currents are used to estimate the motor flux and torque. Based on the instantaneous errors in torque and stator flux magnitude and estimates of the flux position, a voltage vector is selected to limit the flux and torque errors within their flux and torque hysteresis bands. In the conventional DTC, the selected voltage vector applies for the whole switching period, irrespective of the magnitude of the torque error. DTC drive gives variable switching frequency and high torque ripple. DTC gives torque and flux ripples because no any VSI states are capable to generate the exact voltage vector from switching table required to make zero both the torque electromagnetic error and the stator flux error. To minimize this problem, a torque hysteresis band with variable amplitude fuzzy logic controller is proposed. The fuzzy logic controller is used to reduce the flux and torque ripples and it improves performance DTC especially at low speed. A duty ratio control scheme for an inverter-fed induction machine using DTC method is presented in this article. The use of the duty ratio control gives improved steady state torque response, with less torque ripple than the conventional DTC. Fuzzy logic control (FLC) used to implement the duty ratio controller. Total harmonic distortion (THD) calculation of electromagnetic torque, rotor speed and stator current of DTC and DTC with fuzzy has done successfully in this article. With the help of FLC with duty ratio, 8% THD in torque, speed and stator current have minimized compared with DTC (Uddin and Hafeez, 2012). In this paper, switching loses minimization technique through THD minimization. Switching losses are minimized because the transistors are only switched when it is needed to keep torque and flux within their hysteresis bounds, improve efficiency & reduced losses. Direct torque control with the fuzzy logic controller has verified by MATLAB SIMULINK and experimentally.

Comparison performance between sliding mode control and nonlinear control, application to induction motor

A squirrel cage induction motor has been the workhorse in industry for variable speed applications in a wide power range that covers from fractional horsepower to multi megawatts. But the control and estimation of ac drives in general are considerably more complex than those of dc drives. The advent of vector control techniques has partially solved induction motor control problems. However, these techniques are very sensitive to the variation of motor parameters, result in an undesirable coupling between the flux and the torque of the machine, and loss of dynamic performance. To solve these problems this paper presents a synthesis of two control strategies, for controlling speed and rotor flux of induction motor (IM) via nonlinear control (NLC) and sliding mode control (SMC). Computer simulations are carried out to show the robustness of the proposed method against rotor resistance and load torque variations. The performance of SMC has been successfully compared with nonlinear control.

Study on the flux-weakening capability of permanent magnet synchronous motor for electric vehicle

Flux-weakening capability plays an important component part in technical indexes of permanent magnet synchronous motor (PMSM) for electric vehicle. Starting with vector control theory, the influence of motor flux linkage, salient ratio and winding turns on flux-weakening of PMSM have been analyzed in this paper and a prototype is designed based on the analysis result. Then a comparative analysis between theoretical value and measured value is provided to verify the correctness of the analyses.

Finite element modeling and control of a high-power SRM for hybrid electric vehicle

In this study, a new modified fuzzy-PI (MFPI) controller is designed to control a high-power Switched Reluctance Motor (SRM) modeled by means of the finite element method (FEM) for hybrid electric vehicle (HEV) applications. Finite element analysis has been carried out via the Maxwell 2D software package. The motor flux, inductance and torque characteristics obtained from the analyses have been presented. The obtained numerical analysis data was transferred to the Matlab/Simulink environment, and a non-linear dynamic SR motor model was created. The motor speed has been controlled by conventional fuzzy-PI (FPI) and new modified fuzzy-PI (MFPI) controller after designing the nonlinear model of the SRM.The controller performances are compared in terms of maximum percentage overshoot (Os), rise time (tr), steady-state error (ess), rate of torque ripple (Td), and rate of ripple in speed (ωd). The comparisons for the SRM's different operation situations show that MFPI generally yields the better performance in terms of the rise-time, the steady-state error, and the maximum percentage overshoot criteria. In addition, the high-power SR motor simulation computation time (fuzzy computation) for the MFPI controller appears to be shorter than the value for the conventional FPI controller.

Research and development of in-wheel motor driving technology for electric vehicles

The structural form of a driving motor is arranged in the inner wheel hub, which is beneficial to electrification, integration and rationalisation of structure layout. The in-wheel motor is the key part of the electric vehicle driving system, and hence it has significant theoretical values and application values to analyse. Firstly, the development process and the main advantages of in-wheel motor as driving device of the electric vehicles are expounded. Then movement mode and driving method of in-wheel motor are comparatively analysed. Qualitative comparisons and analysis are carried out for induction motor, permanent magnet brushless direct current motor, switched reluctance motor (SRM) and transverse flux motor (TFM), which are regarded as the main electric vehicle driving motors. Finally, the present situation of application and research of in-wheel motor drive electric vehicles in China and abroad is analysed, and the breakthrough directions of in-wheel motor drive technology are proposed.

Swam Intelligent based PI Controller for Flux Weakening Speed Control of an IPMSM Drive

The speed control of an IPMSM is attained by weakening the motor flux using the direct axis and quadrature axis current controllers. This paper demonstrates the application of Swam Intelligent techniques such as Bat algorithm (BA) and Artificial Co-operative Search Algorithm (ACSA) in PI controller design to control the speed of Interior Permanent Magnet Synchronous (IPMSM) motor. The well-known PI controller structure is chosen for these two current controllers. The objective is to minimize the Integral Square Erro r(ISE) of the two current controllers for maximum motor speed. The efficiency of the proposed controller is validated by adding the uncertainty in the torque. The effectiveness of the proposed controller has been successfully verified by means of simulation and the results are evaluated.

Analysis and Implementation of Parallel Connected Two-Induction Motor Single-Inverter Drive by Direct Vector Control for Industrial Application

Sensorless-based direct vector control techniques are widely used for three-phase induction motor drive, whereas in case of multiple-motor control, it becomes intensively complicated and very few research articles in support to industrial applications were found. A straight-forward direct vector control with sensorless operation for parallel connected two similar-rated induction motors driven by single three-phase inverter is proposed and verified numerically by simulation software test under balanced and unbalanced conditions. The proposed control algorithm adapts the natural observer to estimate the rotor speed, rotor flux, and load torque of both motors. Simulation results along with theoretical background provided in this paper confirm the feasibility of operation of the ac motors and proves reliability for industrial applications.

Invention into the AC Voltage Regulator with V/F Technique for Induction Motor Starting Applications

Modern electrical motors are available in many different forms with different mounting arrangements. To ensure a long life for the motor it is important to select it with correct degree of protection when operating under heavy duty conditions in a severe environment. Smooth starting is also one of major considerations to get long life and optimum efficiency. The conventional method to start an asynchronous motor with a soft starter is by reducing the voltage of the motor by varying the voltage “off time”. The “off time” could for example be controlled to achieve a desired maximum current level or a constant driving torque. Even if the voltage is reduced the fundamental frequency of the voltage is equal to the supply voltage frequency. That gives a large difference between angular speed of supply voltage and angular speed of the rotor during start. Due to the large difference in angular speed the motor flux will be low and thereby also the ability to produce torque. Instead of using the conventional control method with a reduced voltage it is possible to use a method with controlled flux similar to frequency inverters for soft-starters. As the soft-starter does not have the intermediate DC energy storage the applied voltage vector has to be directly modulated from the mains supply.

Efficiency analysis of an induction motor with direct torque and flux control at a hot rolling mill

This paper presents an efficiency analysis of an induction motor with direct torque and flux control at a hot rolling mill in South Africa. Two scenarios were evaluated: 1) where the induction motor was controlled at a constant speed with a variable thickness slab; and 2) where the speed of the induction motor was controlled according to the thickness of the slab. Both scenarios used the speed as reference to control the torque and flux of the induction motor. A comparison on the energy consumption of the induction motor for both scenarios was done by means of a detailed simulation model. The simulation model for this specific case study is explained in detail. The results obtained showed an increase in the efficiency of the induction motor from the original system (scenario 1) to the improved system (scenario 2). Part of this paper provides an overview on hot rolling mills.

Performance Analysis of DTC-CSI fed IPMSM Drive at Very Low Speed with Stator Resistance Compensation

Objectives: This paper proposed to enhance the performance of Direct Torque Control (DTC) of CSI fed IPMSM drive with online stator resistances estimation of using PI controller. Methods/Analysis: Direct Torque Control (DTC) CSI fed IPMSM drives have widely used because of its high dynamic performance and no position sensor requires. This scheme is need less parameter to estimate of motor torque and stator flux linkages by using the stator quantities such as voltage and current. The estimation is dependent only the machine parameter such as stator resistance. Findings: At low speed operation the stator resistance is varying due to temperature and frequency which degrade the system performance by introducing errors in flux linkage and motor torque during estimation. Hence the stator resistance compensation is essential at low speed. The error between estimated stator flux and its reference value are used to estimate the stator resistance by using PI controller. For the first time, it is demonstrated in this paper for DTC with CSI fed IPMSM drive system. Conclusion/Application: It is demonstrated for the first time for DTC with CSI fed IPMSM drives. The performance of the stator resistance estimators and torque and flux responses of the drive are investigated with the help of MATLAB/SIMULINK software and hardware. The results show that the proposed methods ensure the reliable and high-performance operation of the drive.

A Matrix Converter Ride-Through Configuration Using Input Filter Capacitors as an Energy Exchange Mechanism

A novel ride-through approach for matrix converters in adjustable speed drives is presented. The input capacitors are utilized to transfer energy from the spinning inertia of the motor to support the motor flux during grid fault events. The addition of three bidirection switches is required to isolate the input filter capacitors from the collapsed grid voltages. The addition of input switches, a ride-through vector control strategy, and post fault reconnection logic are shown to enable ride-through of many cycle faults without the use of an additional energy storage device. In this paper, the control and reconnect strategies are discussed followed by simulations of the system and the presentation of experimental results. Through a short review of power quality assessments, it is shown that these improvements allow matrix converter-based adjustable speed drives to operate in a majority of real world fault situations.

English

In this paper, a new method is proposed to estimate the Stator Resistance for direct torque control of Induction Motor. Direct Torque control of Induction Motor (IM) requires accurate estimation of torque, flux angle and resultant flux and these signals in turn depends on the motor flux. The flux is generally estimated using voltage model equations. The voltage model equation to a large extent depends on the accuracy of stator resistance of the induction motor. The stator resistance varies due to temperature during motor operation. Hence a method based on the active and reactive power is proposed for stator resistance estimation. The effect of stator resistance variation on the flux, torque and flux angle is studied and the results obtained are presented. The proposed method of stator resistance estimation is shown to track the various %changes in stator resistance with good accuracy.

Flux and Position Observer of Permanent Magnet Synchronous Motors with Relaxed Persistency of Excitation Conditions

In this paper we propose a flux and position observer for permanent magnet synchronous motors when voltages, currents and rotor speed are available for measurement. We prove that this observer converges under weaker assumptions than the classical persistence of excitation condition. Simulations confirm the eficacy of the proposed observer and show that it can cope with imprecision in rotor speed measurement, which allows to use an estimator when the speed cannot be measured directly.

Оптимизация состава отряда дорожных машин для зимнего содержания городских улиц и дорог с учетом влияния на режимы движения транспортных потоков

The equations of the regression rate of motor flux on the operating speed of traffic squad cars and watch traffic in the area of works on the main streets of the city. Working units speed road cars invited to take a minimum average speed of traffic flow, taking into account the state of the coating surface, the intensity and composition of traffic. It shows the sequence of calculation of the optimal composition of the detachment of road vehicles for road-maintenance organization, containing the city's road network.

Power loss analysis for switched reluctance motor converter by using electrothermal model

The power converter loss in switched reluctance motor system is one of the main reasons affecting system reliability. Therefore a practical electrothermal model is established to calculate the losses based on lookup tables of motor flux linkage and device switching losses. It utilises the thermal RC network to estimate the junction temperature rise. Then, the influences of system factors on the losses are investigated with different control strategies. At last, the device junction temperature rises are present at different rotor speed, and verified by experiments.

Research on the Cooling System of High-Speed Motorized Spindle

In order to control effectively the temperature of the motorized spindle, based on thermodynamics, heat transfer theory and fluid dynamics control theory, the model of motorized spindle with cooling system is established and simulated. Based on the idea of orthogonal experiment and simulation experiment, the comprehensive tests are built, and the optimum matching relation between the heat flux of motor and the flow velocity of cooling liquid is determined in this article. The results show that the flow velocity of coolant can be adjusted according to the heat flux of motor which can control the temperature in the steady range and improves the cooling effect.

Particle swarm optimization of an extended Kalman filter for speed and rotor flux estimation of an induction motor drive

A novel method based on a combination of the extended Kalman filter with particle swarm optimization (PSO) to estimate the speed and rotor flux of an induction motor drive is presented. The proposed method will be performed in two steps. As a first step, the covariance matrices of state noise and measurement noise will be optimized in an off-line manner by the PSO algorithm. As a second step, the optimal values of the above covariance matrices are injected in our speed–rotor flux estimation loop (on-line). Computer simulations of the speed and rotor flux estimation have been performed to investigate the effectiveness of the proposed method. Simulations and comparison with genetic algorithms show that the results are very encouraging and achieve good performances.

Fluctuating Current Control Method for a PMSM Along Constant Torque Contours

The dc-link voltage fluctuation problem is more serious for an inverter system which utilizes a single phase ac source. As an effort to reduce the dc-link capacitance, there is a tendency to make torque oscillate in synchronism with the input power. Then, the fluctuating motor power matches the converter power. The key idea is to enforce current oscillation along a constant torque line which only affects the reactive power of the motor. In other words, the proposed method uses the motor as inductive energy storage by controlling the motor flux by the reactive current component. Analytic method for obtaining the current bounds was derived. Also, a practical recursive algorithm was proposed. Simulation and experimental results support the effectiveness of the proposed method.

Efficient Multivariable Generalized Predictive Control for Sensorless Induction Motor Drives

This paper presents the design and the experimental validation of a new linear multivariable generalized predictive control for speed and rotor flux of induction motor. This control approach has been designed in the d-q rotating reference frame, and the indirect vector control has been employed. Load and flux observers, as well as the possibility of including a model-reference-adaptive-system speed estimator, have been considered in the implementation. The proposed controller not only provides enhanced dynamic performance but also guarantees compliance with physical voltage and current constraints. Hence, it ensures that the space vector pulsewidth modulation (SVPWM) always operates in the linear area and that the stator windings are not damaged due to overcurrent. Moreover, the controller includes a novel torque current tracker that allows obtaining an effective electromagnetic torque without a chattering phenomenon. Several simulation and experimental tests have been carried out, both in suitable and adverse conditions, even at zero speed zone, demonstrating that the proposed controller provides an efficient speed tracking and suggesting its use in industry.