Dual Three-phase Induction Motor Research Articles

Space-Vector Dynamic Model of Dual-Three Phase Induction Motors with Balanced and Unbalanced Structures in State Form

Space-Vector Dynamic Model of Dual-Three Phase Induction Motors with Balanced and Unbalanced Structures in State Form

Modified SVPWM technique for CMV reduction in asymmetrical dual three phase induction machine drive

Due to its advantages, the asymmetrical dual three-phase induction motor drive is a strong choice in high-power applications. However, the common-mode voltage produced by the voltage source inverters affects the winding insulation and damages the bearings. Common-mode voltage is also responsible for electromagnetic interference and leakage currents. This paper, therefore, analyses the common-mode voltage produced by the inverter supplying a dual three-phase induction motor drive and proposes a novel modified space vector decomposition-based Space Vector Pulse Width Modulation (SVPWM) technique for common mode reduction. The vector space decomposition-based space vector modulation technique offers excellent flexibility as it reduces the common-mode voltage (CMV) by exploiting the additional degree of freedom in a dual three-phase system. The common-mode voltage (CMV) can be reduced to one-sixth of the DC link voltage compared to the highest CMV, i.e. half of the DC-link voltage produced in conventional space vector modulation. The proposed method is also validated experimentally to demonstrate the effectiveness of the proposed scheme in terms of the amplitude of CMV, pulsations, and total harmonic distortion(THD) in current.

Comprehensive Investigation of Space-Vector PWM Including Novel Switching Sequences for Dual Three-Phase Motor Drives

The increasing interest in dual three-phase motor drives has led to the corresponding research on pulsewidth modulation (PWM) techniques. Compared to carrier-based PWM (CPWM), space-vector PWM (SVPWM) attracts more attention because of clear physical meaning and high design flexibility. However, it is difficult to design the method from the space-vector concept due to the complexity in the selection and the arrangement of the space vectors. In this article, with the unified comprehension of the space-vector and carrier-based approaches to PWM, a straightforward approach is proposed to develop various switching sequences. As a result, a total of ten different switching sequences are presented, including five novel switching sequences. In addition, the time distribution schemes of the applied vectors for the derived switching sequences are explored to obtain the acceptable harmonic performance with low computation burden. With the benefit of the derived switching sequences, a comprehensive investigation on the design of PWM methods can be carried out. As a result, an SVPWM method using five active vectors is proposed with excellent harmonic performance. Simulation and experimental results on a 7.5-kW dual three-phase induction motor drive are given to confirm the correctness of the theoretical analysis and the validity of the proposed method.

Priority-Based Model Predictive Control Method for Driving Dual Induction Motors Fed by Five-Leg Inverter

This article proposes a priority-based model predictive control (PMPC) method for a five-leg voltage source inverter (FLVSI) that independently drives dual three-phase induction motors (IMs). In a FLVSI operated by a MPC method, selecting an optimal future voltage vector among all 32 candidate switching states causes a high computational burden. However, by using the PMPC, low computation and current ripples can be achieved at the same time. In the PMPC method, two IMs are prioritized, and the priority of both IMs alternates every control period. For this property, the future voltage vector for the high-priority motor (HM) is selected first; that for the low-priority motor (LM) is selected next. In other words, whereas future switching states of both IMs are optimized by one cost function in the conventional MPCs, those of the HM and LM are optimized by their cost functions in PMPC. Therefore, HM and LM have eight and four candidate voltage vectors for cost minimization, respectively, which results in low computation complexity. Furthermore, current ripples are small because the HM is optimized based on all possible candidate voltage vectors, and both IMs are selected as the HM equally. The PMPC method is demonstrated by simulation and experiment results.

Comparative Analysis of Two Speed-Estimation Methods for Dual Three-Phase Induction Motor with Stator Resistance Online Identification

The dual three-phase induction motor (DTPIM) has gained wide attention in special applications, such as vessel propulsion, because of its advantages of less torque ripple and higher reliability. However, speed sensors are greatly affected and easily become faulty when used in harsh environments for a long time. In this paper, two model reference adaptive system (MRAS) speed-estimation methods are proposed, based on the double (α, β) coordinate system (DCS) and vector space decomposition method (VSD) of the two groups of the three-phase armature vectors, respectively. Both methods can be used for the speed sensorless control system of the DTPIM to improve reliability. The changing of the stator resistance value, caused by temperature variation, affects the accuracy of the speed-estimation. Two online resistance-identification algorithms, combining the DCS method and the VSD method, were proposed to reduce the effect of changes in stator resistance. Simulation results show that the dynamic speed-estimation error of the VSD method decreased greatly compared with the DCS method, which verifies the effectiveness of the theoretical analysis.

Performance Investigation on SVPWM Sequences Based on Reduced Common-Mode Voltage in Dual Three-Phase Asymmetrical Machine

This paper presents Space Vector Modulation (SVM) sequences that reduce Common Mode Voltage (CMV) in Dual Three-phase Asymmetrical Induction Motor (DTAIM). At first, two existing SVM techniques such as Reference SVM (RSVM) and CMV1 are studied. Additionally, three new switching sequences are developed as CMV2, CMV3 and DCMV3, which reduce peak magnitude of CMV by 66.8% in comparison with RSVM technique. In SVM techniques, to obtain least CMV, zero vectors are usually replaced by two opposite large Active voltage Vectors (AV) with equal time duration. In such topologies like CMV1, total six AVs are utilized to synthesize the reference vector. The proposed SVM technique CMV2 utilizes only five large AVs to synthesize the reference vector and reduces CMV. Selection of five neighbouring AVs is reflected in reduction of harmonic flux trajectories and stator current ripple in proposed techniques. Additionally, two more switching sequences (CMV3 and DCMV3) are developed related to utilization of specific zero voltage vectors in all sectors (7 and 56) that produce zero CMV. These two switching sequences also provide easy implementation feature during the development of c-code program. In this study, CMV and stator current ripple are considered as performance parameters for different SVM techniques. All SVM techniques are analysed by analytical results, computer simulations, and using prototype test setup of DTAIM fed by Dual Three-phase Voltage Source Inverters (DTVSIs).

Hybrid Loss Minimization Control For Dual Three-phase Linear Induction Motor

Dual three-phase linear induction motor has harmonic losses that cannot be included in the loss-flux model in the z1-z2 subspace obtained by the generalized Clarke transform. The loss model of α-β subspace is not optimal for obtaining the reference flux. To solve this problem, losses in harmonic subspace was analyzed, and then a hybrid loss minimization control strategy was proposed. Based on the loss model that considers the end effect in the d-q subspace (transformed from α-β subspace), suboptimal flux linkage calculated by the model is set as the starting point of search controller, and optimal operating point could be obtained. Finally, the simulation results show that the strategy has better response performance than the traditional search method, and there is a certain loss reduction under various working conditions, especially at light load (0.2pu, 5 m/s), there is about 48.2% loss reduction.

Speed Control of Dual Induction Motor Using Five Leg Inverter

Over the past decade, research efforts have been made to decrease the number of power electronic devices needed in multi-motor drive systems in order to condense the overall complication and cost of the drive. This paper proposes speed control for a dual three-phase induction motor system driven by five-leg voltage source inverter (FL-VSI) which is used in industrial manufacturing processes. Industrial applications frequently need a number of variable speed electric drives. This technique uses five-leg inverter instead of using conventional two three phase inverters. In the majority of cases, these multi-motor drive systems need independent control of individual motors. It is shown recently that it is possible to separately control two three-phase induction machines supplied through a five-leg voltage source inverter, with one inverter leg being common to both machines. The entire performance of the speed control for the five leg voltage source inverter fed dual-motor drive system is investigated using MATLAB/SIMULINK software.

Advanced Speed Control for a Five-Leg Inverter Driving a Dual-Induction Motor System

This paper proposes advanced speed control for a five-leg voltage source inverter (FLVSI) that drives the dual three-phase induction motor system used in industrial manufacturing processes. The advanced speed control method consists of two controllers: 1) The first is a slip controller that satisfies the application requirement, i.e., to control the mechanical speed of two motors equally regardless of the load condition. 2) The second is an angle controller that satisfies the FLVSI requirement, i.e., to control the phase angle difference between the two motors for minimizing the common leg current because the common leg current can be twice higher than other leg's current depending on the operation condition of the dual motor. Stability analysis of the two controllers under advanced speed control is implemented, and the whole performance of the advanced speed control for the FLVSI-fed dual-motor drive system is shown to identify its feasibility through the experimental results.

A Comparative Study of PWM Techniques for Multiphase Induction Motor Drives

Abstract This paper deals with the performance analysis of different PWM techniques for three-phase and dual three-phase induction motors. In this paper, the dual three-phase induction motor is reconnected as a three-phase and six-phase winding configurations and its performances are investigated. The comparative evaluation for the aforesaid machine configurations are carried out in terms of quality of stator current waveform with different PWM techniques. Total harmonic distortion are obtained in terms of harmonic distortion factor for stator current. The theoretical findings are further verified through simulation and experimental results.

Experimental analysis of various space vector pulse width modulation (SVPWM) techniques for dual three-phase induction motor drive

Experimental analysis of various space vector pulse width modulation (SVPWM) techniques for dual three-phase induction motor drive

Design and Implementation of an FPGA-based Real-time Simulator for a Dual Three-Phase Induction Motor Drive

This paper presents a digital hardware implementation of a real-time simulator for a multiphase drive using a field-programmable gate array (FPGA) device. The simulator was developed with a modular and hierarchical design using very high-speed integrated circuit hardware description language (VHDL). Hence, this simulator is flexible and portable. A state-space representation model suitable for FPGA implementations was proposed for a dual three-phase induction machine (DTPIM). The simulator also models a two-level 12-pulse insulated-gate bipolar transistor (IGBT)-based voltage-source converter (VSC), a pulse-width modulation scheme, and a measurement system. Real-time simulation outputs (stator currents and rotor speed) were validated under steady-state and transient conditions using as reference an experimental test bench based on a DTPIM with 15 kW-rated power. The accuracy of the proposed digital hardware implementation was evaluated according to the simulation and experimental results. Finally, statistical performance parameters were provided to analyze the efficiency of the proposed DTPIM hardware implementation method.

A novel over-modulation strategy for dual three-phase induction motor drive system

In this article, a novel strategy for dual three-phase converter operating in the over-modulation region is proposed. The strategy enables the magnitude of inverter output voltage a linear output with modulation index varying in both fundamental and harmonic components. In the proposed algorithm, the functional relationship between modulation index and the fundamental or harmonic voltage magnitude can be described by equations. It is a single-mode over-modulation strategy avoiding storing massive correlation data between modulation index and hold angle, which indicates the proposed algorithm is suitable for digital implementation. Furthermore, this strategy extends the range of operation of the power converter from linear-modulation range to 12-step operation with a smooth and linear transition characteristic, while stator harmonic current is suppressed based on a vector decomposition technique.

AC Drive System with Multiphase Induction Motor for High Power Mining Haul Trucks

Electric mining haul trucks are one of the most challenging applications of power electronics in automotive systems. This paper presents some advances of AC drive system with multiphase induction motor in high power mining haul trucks used in the special operation and environment. It is established that the use of inverter-fed dual three-phase (DTP) induction motors with vector control is the preferred solution to reach the required high starting torque, widely variable-speed range and good dynamic performance required by these vehicles. Key technologies and design features for the drive systems under extreme operating conditions are discussed.

Parameters On-line Identification of Dual Three Phase Induction Motor by Voltage Vector Injection in Harmonic Subspace

This paper introduces a novel method of on-line identifying the stator resistance and leakage inductance of dual three phase induction motor (DTPIM). According to the machine mathematical model, the stator resistance and leakage inductance can be estimated using the voltage and current values in harmonic subspace. Thus a method of voltage vector injection in harmonic subspace (VVIHS) is proposed, which causes currents in harmonic space. Then the errors between command and actual harmonic currents are utilized to regulate the machine parameters, including stator resistance and leakage inductance. The principle is presented and analyzed in detail. Experimental results prove the feasibility and validity of proposed method.

Research on Rotor Field Oriented Control of Dual-Three Phase Induction Machine

In this paper, the mathematical model of dual three-phase induction motor is constructed based on space vector decomposition. The rotor field oriented control of the motor is then proposed. The simulation model of the motor is constructed in Matlab/Simulink/PLECS software. Simulation systems of the start-up transient and the rotor field oriented control of the motor are established. The simulation results validate the model and the effectiveness of the proposed control method.

New Space Vector Selection Scheme for VSI Supplied Dual Three-Phase Induction Machine

This paper presents a novel space vector selection scheme applicable for the control of dual three-phase induction motor drives supplied from a six-phase voltage source inverter (VSI). ...

Experimental Tests of Dual Three-Phase Induction Motor Under Faulty Operating Condition

This paper describes a set of experimental tests on a dual three-phase induction machine for fault-tolerant applications. Both three-phase and six-phase machine operations are considered. Different winding configurations are investigated and compared in case of both open-circuit and short-circuit faults. Experimental tests for each configuration are reported at no-load and under load operating conditions.

Predictive-space vector PWM current control method for asymmetrical dual three-phase induction motor drives

The interest in multiphase drives has re-emerged in the last decade, being the asymmetrical dual three-phase induction motor drive one of the most popular options. Predictive control techniques, already implemented in three-phase drives, have been recently adapted to the multiphase case. Schemes proposed so far have demonstrated high performance at the expenses of a higher degree of computational cost and ill-defined switching frequency. In this study, a predictive space vector PWM (SVPWM) current control technique with fixed switching frequency is proposed for asymmetrical dual three-phase AC drives. Fast torque and current response are achieved similar to those obtained using conventional predictive current control techniques. Electrical noise suppression is favoured as in PWM current control methods. Experimental results are provided to examine the benefits of the proposed control method.

Restrained search predictive control of dual three-phase induction motor drives

The interest in multiphase drives has re-emerged in the last decade, being the dual three-phase induction motor drive one of the most popular options. Predictive control techniques, already implemented in three-phase drives, have been recently adapted to the multiphase case. Schemes proposed so far have restricted the available number of voltage source inverter (VSI) switching vectors but do not impose any constraint on the allowable commutations of these vectors. This paper proposes not to select a subgroup of possible VSI switching vectors, but to constrain the commutations involved in the next sampling period. This procedure allows decreasing the switching period and improving the predictive control performance. The viability and effectiveness of the proposal is verified by simulation.