Rotor field oriented control strategy of multiphase induction motor

Based on studying the transform theory of the multiphase system and the rotor field oriented control (RFOC) of multiphase induction motor (IM), the mathematical modulation of RFOC used in multiphase IM with closed-loops of harmonic currents is modeled. It can be used to solve the problems of harmonic currents in the conventional vector control of multiphase IM. The fundamental current and each of harmonic currents can be controlled independently for decoupling. The harmonic currents can be restrained effectively. In the paper, a nine-phase IM is proposed to verify the hypothesis. Experimental results confirm the theoretical analysis well. The paper further achieves the technology of electronic pole changing (EPC) under RFOC of multiphase IM. It is feasible for multiphase IMto realize pole-changing without cutting off the power and the EPC proposed could effectively extend the operational range of constant power in multiphase IM.

In order to improve the operation performance of AC drive system, a combined control strategy for matrix converter fed induction motor drive system is proposed, which implements both space vector modulation of matrix converter and direct field oriented control of induction motor. Using this combined control strategy, it is possible to combine the advantages of matrix converter and the advantages of vector control technique and realize high performance control of induction motor. Applied with Matlab/Simulink, the simulation of the matrix converter with such strategy is carried out and the results of simulation are presented. Inductive load simulation is carried out on this matrix converter prototype. The simulation results verify the workability of the vector control strategy for matrix converter and the control performance of AC drive system is improved.

In this paper, a new control strategy is proposed which is simple in structure and has the straightforward goal of minimizing the stator current amplitude for a given load torque. It is shown that the resulting induction motor efficiency is reasonably close to optimal and that the approach is insensitive to variations in rotor resistance. Although the torque response is not as fast as in field-oriented (FO) control strategies, the response is reasonably fast. In fact, if the mechanical time constant is large relative to the rotor time constant, which is frequently the case, the sacrifice in dynamic performance is insignificant relative to FO strategies.

This paper analyzed a dead-time effect and zero-current clamping phenomenon in FOC control strategy, and then proposed corresponding compensation measures. The Field Oriented Control (FOC) strategy of brushless motor is improved according to this Dead-time Compensation measure. On the basis of the existing FOC control theory, a dead-time hysteresis loop is added near the current zero-crossing point to prevent current fluctuation and zero-point clamping from causing errors. The dead-time compensation is carried out in each PWM cycle according to the principle that the actual volt-second area is equal. Finally, the feasibility of the method was verified by experiments, the results showed that the compensation method effectively improves the current waveform and improves the stability of the motor operation, and it proved to be of good use value.

In this paper, a control scheme for multiphase induction motor drives is presented and assessed. This control scheme ensures the operation of a multiphase drive under an open-circuit phase fault that can occur in one or more phases at the same time. A fault-tolerant control strategy is developed. The mathematical analysis is based on the space vector representation of the multiphase system and is valid either in transient or steady-state operating conditions. The feasibility of the drive is verified by means of experimental tests carried out on a prototype of seven-phase induction motor.

This paper proposes a finite control set model predictive control (FCS-MPC) based dual-motor control strategy for induction motor (IM) and permanent magnet synchronous motor (PMSM). By establishing a dual-motor current prediction model, the unified cost function and optimization strategy are constructed, and the torque synchronization constraint and total torque ripple suppression constraint are designed. Compared with the traditional control strategy, the proposed control algorithm verifies the feasibility of FCS-MPC in the IM-PMSM dual-motor system. Moreover, the proposed strategy has good transient performance, and realizes the torque synchronous control and total torque ripple suppression of the dual-motor system.KeywordsInduction motorPermanent magnet synchronous motorFinite control set model predictive controlDual-motor

Introduction. A new control strategy based on the combination of optimal model predictive control (OMPC) with fractional iterative learning control (F-ILC) for speed regulation of an induction motor (IM) for electric vehicles (EVs) application is presented. OMPC uses predictive models to optimize speed control actions by considering the dynamic behavior of the IM, when integrated with the F-ILC, the system learns and refines the speed control iteratively based on previous iterations, adapting to the specific characteristics of the IM and improving performance over time. The synergy between OMPC and F-ILC named F-ILC-OMPC enhances the precision and adaptability of speed control for IMs in EVs application, and optimizes the energy efficiency and responsiveness under varying driving conditions. The novelty lies in the conjunction of the OMPC with the ILC-based on the fractional calculus to regulate the speed of IMs, which is original. Purpose. The new control strategy provides increased performance, robustness and adaptability to changing operational conditions. Methods. The mathematical development of a control law that mitigates the disturbance and achieves accurate and efficient speed regulation. The effectiveness of the suggested control strategy was assessed via simulations in MATLAB conducted on an IM system. Results. The results clearly show the benefits of the F-ILC-OMPC methodology in attaining accurate speed control, minimizing steady-state error and enhanced disturbance rejection. Practical value. The main perspective lies in the development of a speed control strategy for IMs for EVs and the establishment of reliable and efficient electrical systems using ILC-OMPC control. This research has the prospect of a subsequent implementation of these results in experimental prototypes. References 24, tables 2, figures 9.

An attempt has been made to analyze the methods to improve the electromagnetic properties of a solid-rotor induction motor. The slip of the solid rotor is reduced notably if the solid rotor is axially slitted. The slitting patterns of the solid rotor are examined. It is shown how the slitting parameters affect the produced torque. Finite element analysis is used to numerically analyze the effect of axial slitted rotor on the electromagnetic performance characteristics of a 180 kW, 170 Hz 3-phase induction motor. The paper considered the effect of variation of slit depth, variation of no of rotor slits and the variation of air gap length on the performance of 3-phase induction motor using Flux-2D Maxwell software package from ANSYS. It is found that larger and deeper slit of the rotor with minimum valve of air gap gives the better and higher operating torque. It is also found that deeper slit gives the higher efficiency of the slitted rotor, high speed induction motor.

In this paper, the maximum power point (MPP) of photovoltaic (PV) for vector control of an induction motor (IM) driving water is achieved. This paper implements and analyzes the maximum power point tracking (MPPT) in one stage. The vector control scheme for an induction motor has been introduced to improve the reliability of the PV system. Furthermore, the Adaptive incremental conductance (AINC) method has been applied to track the maximum power point (MPP) of the PV plant. Additionally, the principles of vector control of an induction motor are used for voltage source inverter fed induction motor pumping system. The control scheme is simulated and validated considering the environmental conditions such as solar radiation and temperature. The scheme has been validated through MATLAB/SIMULINK. The obtained results and analysis authorize that, the proposed control system is accurate and effective. In addition, the results show that, the induction motor drive is stable during dynamic and ‎steady-state conditions.‎

This paper presents a simplified self-tuned Sugeno type neuro fuzzy controller (NFC) based direct torque control (DTC) scheme for induction motor (IM) drive. A simple tuning algorithm is developed based on the reference and actual acceleration of the motor. The online tuning strategy adjusts the parameters of the consequent layer of the NFC in such a way to minimize the square of the error between actual and reference acceleration of the IM. In a conventional DTC scheme the band limits of flux and torque hysteresis controllers remain fixed and hence the torque and flux ripples are high. In order to optimize the torque ripples of the IM the hysteresis band limits are adjusted online for the torque hysteresis controller. In order to test the performance of the proposed NFC based DTC scheme for IM drive a complete simulation model is developed using MATLAB/Simulink. The proposed NFC based DTC scheme is implemented in real-time using DSP board DS1104 for a prototype 1hp squirrel cage IM. The performance of the proposed drive is tested at different operating conditions in both simulation and experiment.

Variable speed induction motor drives find applications in various industries. The normal Induction Motor drive has a closed loop speed control. Here, we use a Multi- Level Inverter (MLI), which has emerged as an alternative in the medium-voltage high-power control to feed the Induction Motor. The Multi-Level Inverter employs a new topology known as the reversing voltage topology (RVT). To generate output voltage with higher number of levels, this topology requires less number of components and less carrier signals for PWM implementation. The proposed induction motor drive structure offers reduced device count and a simpler power-bus structure when compared to a conventional five-level NPC and flying capacitor inverter fed induction motor drives. The Induction Motor is controlled by the scalar method of Direct Torque Control (DTC). This scheme is the direct control of the torque and stator flux of a drive by inverter voltage space selection through a look-up table to maintain speed at reference. Performance comparison for various voltage vector selections has been made. This technique has a comparable performance with that of vector controlled drives

In-depth cross-coupling analysis in high-performance induction motor control

A Direct Torque Control (DTC) strategy for dual-three phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees with isolated neutral points. The proposed control strategy is based on Proportional Integral (PI) regulators implemented in the stator flux synchronous reference frame. To improve the flux estimation, an Adaptive Stator Flux Observer (ASFO) has been used. Doing so, besides a better flux estimation in contrast to open-loop flux estimators, it is possible to use the observed currents to compensate the inverter non-linear behavior (such as dead-time effects), improving the drive performance at low speed. This is particularly important for low voltage/high current applications, as the drive considered in this paper.The advantages of the discussed control strategy are: constant inverter switching frequency, good transient and steady-state performance and less distorted machine currents in contrast to DTC schemes with variable switching frequency. Experimental results are presented for a 10kW dual three-phase induction motor drive prototype.

The Dynamic response of induction motor (IM) drive relies on control technique used. Field Oriented Control (FOC) and Direct Torque Control (DTC) are the two strategies to improve the dynamic performance of IM drives. For Electric Vehicles (EV’s) reduced ripples in torque and flux is required. This article, Introduces Predictive Torque Control (PTC) strategy for an Open-end Winding Induction Motor Drive (OWIMD) with four-level inversion by using selective voltage vectors to reduce torque ripples, flux ripples and computational burden on controller. The classical PTC (C-PTC) has the problem of high torque ripples, flux ripples, complex tuning of weighting factors and computational burden. This article utilizes the concept of reactive torque to eliminate weighting factor and flux sector information to apply selective voltage vectors. By using these two strategies, the proposed PTC algorithm will maintain less ripples and computational burden. To validate the proposed PTC, the obtained simulation results are compared with classical PTC.

High-power boost converter is an important part in supercapacitor energy storage system. The decline of supercapacitor's terminal voltage should be considered when design the converter. The advantages and disadvantages of the asymmetry half-bridge bidirectional converter are discussed. A novel PWM phase-shift plus feed-forward control method was proposed, which uses input voltage feed-forward to control duty cycle and output voltage feed-back to control phase shift angle. This control strategy could reduce the peak current of the transformer's leakage inductance, promote the converter's efficiency and ensure the switches' ZVS. The converter's operation is analyzed and the average model and small signal model are built. The control system was designed. The control strategy was verified by simulation.