Control Of Induction Machine Research Articles

Min-Max Predictive Control of a Five-Phase Induction Machine

In this paper, a fuzzy-logic based operator is used instead of a traditional cost function for the predictive stator current control of a five-phase induction machine (IM). The min-max operator is explored for the first time as an alternative to the traditional loss function. With this proposal, the selection of voltage vectors does not need weighting factors that are normally used within the loss function and require a cumbersome procedure to tune. In order to cope with conflicting criteria, the proposal uses a decision function that compares predicted errors in the torque producing subspace and in the x-y subspace. Simulations and experimental results are provided, showing how the proposal compares with the traditional method of fixed tuning for predictive stator current control.

Optimized Current Trajectory Tracking Control of a Five-Phase Induction Machine Under Asymmetrical Current Limits

The fault-tolerant ability is a significant advantage of multiphase machines over the three-phase ones. Parallel connections of stator windings or converter legs are preferred to enhance the power rating or drive performance. Open-circuit faults on parallel branches are reflected as the derating of current limits for the corresponding phases, and fault-tolerant strategies are required to keep the phase currents within asymmetrical current limits. This article analyzes the optimal phase current trajectories of a five-phase induction machine under three different faulty scenarios in parallel situations and then proposes the offline optimized current trajectory tracking (OCTT) fault-tolerant strategy, which can reach the maximum achievable fault-tolerant power while guaranteeing optimized ohmic losses over the full power range. Furthermore, based on the generalized symmetrical components theory, an extended rotor field-oriented control (RFOC) is proposed to realize the OCTT mode in field-oriented control. Experimental results confirm the efficiency improvement of the OCTT mode in the full-power-range operation and verify the asymmetrical current trajectory tracking ability of the extended RFOC.

Design and Implementation of Luenberger Model-Based Predictive Torque Control of Induction Machine for Robustness Improvement

This letter proposes a Luenberger model-based predictive torque control (LM-PTC) of induction machine to compensate prediction error caused by mismatched parameters. In the traditional predictive torque control (T-PTC), stator current, stator flux vector, and electromagnetic torque are predicted in one sampling period by open-loop prediction model, which will inevitably lead to prediction error by mismatched parameters, first. Inspired by the idea of closed-loop Luenberger observer, in the torque and flux prediction, the feedback correction part is introduced into prediction equations for LM-PTC. Second, the steady prediction errors of T-PTC and LM-PTC are, respectively, analyzed with mismatched parameter. Finally, the proposed LM-PTC is verified by the comparison experiments including dynamic-state, transient-state, and steady-state experiments.

Direct space vector modulation for matrix converter fed dual star induction machine and neuro-fuzzy speed controller

This paper presents the modeling, design, and simulation of an adaptive neuro fuzzy inference strategy (ANFIS) for controlling the speed of the Double Star induction Machine (DSIM), the machine is fed by three phase direct matrix converter which makes directly AC-AC power conversion is modeled using Direct Space Vector Modulation technique(DSVM) for direct matrix converter. Double star Induction motor is characterized by highly non-linear, complex and time-varying dynamics and inaccessibility of some of the states and outputs for measurements. Hence it can be considered as a challenging engineering problem in the industrial sector. Various advanced control techniques has been devised by various researchers across the world. Some of them are based on the neuro-fuzzy techniques. The main advantage of designing the ANFIS coordination scheme is to control the speed of the DSIM to increase the dynamic performance, to provide good stabilization. To show the effectiveness of our scheme, the proposed method was simulated on an electrical system composed of a 4.5 kW six-phase induction machine and its power inverter. Digital simulation results demonstrate that the deigned ANFIS speed controller realize a good dynamic of the DSIM, a perfect speed tracking with no overshoot, give better performance and high robustness.

Imposed Switching Frequency Direct Torque Control of Induction Machine Using Five Level Flying Capacitors Inverter

Imposed Switching Frequency Direct Torque Control of Induction Machine Using Five Level Flying Capacitors Inverter

Parallel Predictive Torque Control for Induction Machines Without Weighting Factors

Finite control set model predictive control (FCS-MPC) calculates torque and flux tracking errors via a cost function that is used for selecting the optimal vector. Compared with field oriented control, FCS-MPC has the merit of a faster dynamic performance because it eliminates both pulsewidth modulation and inner proportion-integration controllers. However, the weighting factor for modifying torque and flux terms must be tuned in accordance with varying operating conditions; this is an area in which further research is needed. In this paper, a parallel predictive torque control (PPTC) with predefined constraints is proposed as a solution for this problem. The PPTC method optimizes torque and flux terms simultaneously, and switching-state candidates are then selected in an adaptive mechanism. The key feature is that torque and flux tracking errors are constrained within the initial boundaries. The proposed PPTC is compared with the state-of-the-art predictive torque control (PTC) method. Both simulation and experimental results confirm that the proposed method, which has no weighting factor, achieves an even better dynamic performance and robustness than the conventional PTC.

Vector Control of a Single-Phase Induction Machine with Scott-T Connection in the Stator and Estimation of Velocity with Sliding Mode Observer

This paper shows a high-performance sensorless driver for an induction machine with a Scott-T connection in the stator windings.This connection is used to transform a single-phase machine into a three-phase only by changing the winding configuration, increasing efficiencyand minimizing the cost impact. This type of solution can be used as an alternative to the use of highperformance drivers controlling single-phaseinduction machines. The motor model using the Scott-T connection is developed and the experimental results of a vector control approach by fieldorientation are shown. A sliding mode observer is also developed for estimating the speed of the machine tested.

Penentuan Parameter Pemodelan Kecepatan Putar Motor Induksi 3 Phasa Menggunakan Jaringan Saraf Tiruan (JST)

Modeling speed control of induction machines 3 phase is very necessary, because will be make it more easier for used in mathematic analysis. In this book simulating modeling parameters is purposing give solution for made mode speed control induction machine 3 phase. And analysis using Universal Field Oriented (UFO) and Direct Field Oriented (DFO). Speed control machine 3 phase can be adapted with changing of load, so that using Neural Network. Result from analysis in this paper to give parameters mode adaptive control system in diagram block type.

Active Disturbance-Rejection-Based Speed Control in Model Predictive Control for Induction Machines

Finite set model predictive torque control (FCSMPTC) of induction machines has received widespread attention in recent years due to its fast dynamic response, intuitive concept, and ability to handle nonlinear constraints. However, FCSMPTC essentially belongs to the open-loop control paradigm, and unmatched parameters inevitably cause electromagnetic torque tracking error. In addition, the outer loop (i.e., the speed loop) based on a proportional-integral (PI) regulator cannot achieve optimal control between speed dynamic response and torque tracking error compensation. The traditional control paradigm is abbreviated as PI-MPTC. In order to solve the aforementioned problem, this paper proposes active disturbance-rejection-based model predictive torque control (ADR-MPTC). First, the influence mechanism of mismatched parameters on torque prediction error in PI-MPTC is studied, and then the performance of a traditional PI regulator used to compensate for torque prediction error is analyzed. Second, this paper introduces several parts of the proposed ADR-MPTC, including the design of the torque prediction error observer, nonlinear prediction error compensation strategies, an enhanced predictive torque control, and a simplified full-order flux observer. Finally, PI-MPTC and ADR-MPTC are studied experimentally. The experimental results show that compared with PI-MPTC, ADR-MPTC performs better in dynamic and steady states, and has stronger robustness.

A robust-adaptive linearizing control method for sensorless high precision control of induction motor

Even if there exists remarkable applications of induction machines in variable speed drives and also in speed sensorless control in the low–high speed region, open/closed loop estimators in the literature utilized on induction machine sensorless position control vary regarding to their accuracies, sensitivity, and robustness with respect to the variation of model parameter. The deterioration of dynamic performance depends on the lack of estimation techniques which provide trustable information on the flux or speed/position over a wide speed range. An effective estimator should handle the high number of parameter and model uncertainties inherent to induction machines and also torque ripple, the compensation of which is crucial for a satisfactory decoupling and linearizing control to provide the accuracy and precision requirements of demanding motion control in the field of robotics/unmanned vehicle. In this study, to address all of the above-mentioned problems, robust-adaptive linearizing schemes for the sensorless position control of induction machines based on high-order sliding modes and robust differentiators to improve performance were designed. The control schemes based on direct vector control and direct torque control are capable of torque ripple attenuation taking both space and current harmonics into account. The simulation results comprise both the estimation and sensorless speed control of induction machines over a wide operation range, especially at low and zero speed, all of which are promising and indicate significant superiority over existing solutions in the literature for the high precision, direct-drive, speed/position sensorless control of squirrel-cage induction machines.

Enhanced rotor field‐oriented control of multiphase induction machines based on symmetrical components theory

Fault-tolerant capability greatly promoted the application of multiphase machines on safety-critical occasions, and fault-tolerant control strategies are required to suppress the torque ripples. Based on the generalised symmetrical components (SCs) theory, a general expression of the independent SCs is derived during the fault-tolerant operation of symmetrical multiphase machines in this study, and coefficients of the four basic rotating components in the general expressions are calculated for specific open-circuit conditions. Then the bidirectional rotating proportional–integral controllers are designed to control all the rotating components in each SC. Considering control loops for all the independent SCs, an enhanced rotor field-oriented control fault-tolerant strategy is proposed for symmetrical multiphase induction machines (IMs) with any phase number m . Furthermore, additional rotating current controllers in the first SC control loop are added to reduce the low-order current harmonics during the fault-tolerant operation. Experimental evaluations in terms of the transient, dynamic and harmonic performances on both five-phase and nine-phase IM drive platforms are provided to verify the effectiveness of the proposed fault-tolerant strategy.

Robustness Improvement of FCS-MPTC for Induction Machine Drives Using Disturbance Feedforward Compensation Technique

Finite control set-model predictive torque control (FCS-MPTC) has a fast dynamic response because this algorithm directly selects the optimal voltage vector by its cost function for induction machine drives fed by voltage source inverter (VSI). However, belonging to open-loop control paradigm, the FCS-MPTC has torque tracking error due to inevitable load disturbance and mismatched model parameters in reality. In traditional FCS-MPTC, the outer loop, i.e., speed loop, adopts a classic proportional integral (PI) controller, abbreviated as PI-MPTC. The lumped disturbance is only suppressed by a PI controller. However, pole placement of the PI controller is usually designed by cut-and-trial, which is difficult to simultaneously achieve optimal dynamic performance and optimal suppression of lumped disturbance. In this paper, the FCS-MPTC with mismatched parameters is first analyzed. Second, the deficiencies of the traditional PI controller are introduced. Third, disturbance feedforward compensation-based-model predictive torque control (DFCB-MPTC) of induction machine is proposed to compensate lumped disturbance and improve the performance of the system. Furthermore, a simplified stator flux observer is proposed, whose gain matrix is independent of rotor speed. Experimental results verify the feasibility of the proposed DFCB-MPTC. Compared with traditional PI-MPTC, the proposed DFCB-MPTC has better dynamic performance, steady performance, and stronger robustness.

Optimal control strategy of an induction motor for loss minimization using Pontryaguin principle

This paper presents a new design of loss-minimization optimization control for Induction Machine (IM) drives. It describes a closed-loop optimal control law and exploits the Pontryagin principle to get optimal energy consumption. This proposal is based on the Optimal Control Problem (OCP) which focuses on minimizing a cost function given as an integral of a weighted sum of the mechanical power, copper losses and magnetic power of the IM. In order to minimize the IM energy consumption, we consider a normalized cost function with respect to the optimization finite-interval [0,T]. This functional is subjected to dynamic constraints which are developed from a reduced IM model. The system depends on two state variables: the rotor flux and the motor speed. The proposed method provides an optimal rotor flux that performs the minimal energy consumption of an IM along a given torque and velocity. This OCP conducts to a system of combined nonlinear differential equations of state and co-state variables. Long and hard developments lead to many calculus steps. Finally, an optimal time-varying rotor flux is successfully turned out. This OCP satisfies also abrupt torque conditions and can cover dynamic operations when the proposed solution fulfills some criteria of sub-optimality. The validity of the suggested optimal control design is tested via simulation and then via experimental results by comparing a dynamic control law using the proposed optimal rotor flux trajectory with a conventional control utilizing the rated flux value.

Current Control of a Six-Phase Induction Machine Drive Based on Discrete-Time Sliding Mode with Time Delay Estimation

This paper proposes a robust nonlinear current controller that deals with the problem of the stator current control of a six-phase induction motor drive. The current control is performed by using a state-space representation of the system, explicitly considering the unmeasurable states, uncertainties and external disturbances. To estimate these latter effectively, a time delay estimation technique is used. The proposed control architecture consists of inner and outer loops. The inner current control loop is based on a robust discrete-time sliding mode controller combined with a time delay estimation method. As said before, the objective of the time delay estimation is to reconstruct the unmeasurable states and uncertainties, while the sliding mode aims is to suppress the estimation error, to ensure robustness and finite-time convergence of the stator currents to their desired references. The outer loop is based on a proportional-integral controller to control the speed. The stability of the current closed-loop system is proven by establishing sufficient conditions on the switching gains. Experimental work has been conducted to verify the performance and the effectiveness of the proposed robust control scheme for a six-phase induction motor drive. The results obtained have shown that the proposed method allows good performances in terms of current tracking, in their corresponding planes.

Speed control of a doubly-fed induction machine based on fuzzy adaptive

In this paper, we are interested in the adaptive fuzzy control a technique has been studied and applied, namely adaptive fuzzy control based on theory of Lyapunov. The system based on the stability theory is used to approximate the gains ke and kdce to ensure the stability of the control in particular time, simulations results obtained by using MATLAB environment gives that the fuzzy adaptive control more robust, also it has superior dynamics performances. The results and test of robustness will be presented.

Simulated topology of doubly powered asynchronous motor with diode clamped inverter

This paper deals with the problem of modelling, control and analysis of a doubly-powered induction machine (DPIM) using a three-level three-phase voltage source inverter known simply as diode clamped inverter (DCI) with a three-phase diode rectifier and a DC link in between. A mathematical model of DPIM and the associated DCI circuit is developed. The stator circuit of the DPIM is supplied directly from an ac system network while its rotor side is supplied via a variable frequency DCI. A multi-loop nonlinear field controller is developed to meet an accurate motor speed, regulation of the mechanical load torque and the overall system power. The results obtained from the simulation in the environment of Simplorer 7 show that the proposed DCI inverter offers great optimisation, little overshoot, and reduced voltage ripples. Consequently, the dynamic behaviour of the motor and the energy efficiency of the overall system are progressively improved and a complete suppress of the influence of the variation in the motor load on the speed of the motor is achieved.

Speed control of a doubly-fed induction machine based on fuzzy adaptive

In this paper, we are interested in the adaptive fuzzy control a technique has been studied and applied, namely adaptive fuzzy control based on theory of Lyapunov. The system based on the stability theory is used to approximate the gains ke and kdce to ensure the stability of the control in particular time, simulations results obtained by using MATLAB environment gives that the fuzzy adaptive control more robust, also it has superior dynamics performances. The results and test of robustness will be presented.

Simulated topology of doubly powered asynchronous motor with diode clamped inverter

This paper deals with the problem of modelling, control and analysis of a doubly-powered induction machine (DPIM) using a three-level three-phase voltage source inverter known simply as diode clamped inverter (DCI) with a three-phase diode rectifier and a DC link in between. A mathematical model of DPIM and the associated DCI circuit is developed. The stator circuit of the DPIM is supplied directly from an ac system network while its rotor side is supplied via a variable frequency DCI. A multi-loop nonlinear field controller is developed to meet an accurate motor speed, regulation of the mechanical load torque and the overall system power. The results obtained from the simulation in the environment of Simplorer 7 show that the proposed DCI inverter offers great optimisation, little overshoot, and reduced voltage ripples. Consequently, the dynamic behaviour of the motor and the energy efficiency of the overall system are progressively improved and a complete suppress of the influence of the variation in the motor load on the speed of the motor is achieved.

H∞ Current Controller of WRIM Based Flywheel Storage System under Unbalanced Stator Voltage

Flywheel storage systems (FSSs) are commonly associated with wind farms to support them to provide services to the grid such as power smoothing, frequency control, and voltage control. Although FSSs are not concerned by the grid code requirements, their stability and availability under unbalanced stator voltages are very important to ensure both wind farm stability and supply quality. In this context, this paper proposes a robust H ∞ controller for wound rotor induction machine (WRIM) driven FSS under stator voltage unbalance. The controller purpose is to suppress rotor current oscillations resulting from the negative sequence as well as to guarantee the system robustness in the presence of parameter uncertainties. The robust controller design based on mixed-sensitivity H ∞ control that guarantees the robust stability (RS) and robust performance (RP) is presented in detail. The performance of the H ∞ controller has been evaluated with simulations in MATLAB/Simulink using simpower systems for both unbalanced stator voltage and parameter uncertainties.

Direct torque control of induction machine drive based on sliding mode controller and a stator resistance compensator with a new hybrid observer

This paper presents a sensorles direct torque control (DTC) based on sliding mode controller approach (SMC) applied to an induction machine (IM) drive. The DTC is one of the excellent strategies. It aims to provide decoupled control of torque and flux. However, his main problem is the high torque and flux ripples of the devices. Its drawback was rectified with the use a control scheme that combined with SMC strategy. The rotor speed estimation is done by an observer using the model reference adaptive system (MRAS) technique whereas the nonlinear sliding mode observer (SMO) is used to get the rotor flux. The main aim is to achieve a robust and efficient control, which will allow us to test and evaluate the performance of the proposed observer, combined with sensorless control of the IM. The simulations results show the effectiveness of the proposed sensorless control scheme.