Multiphase Induction Motor Research Articles

A Generalized Overmodulation Strategy With Minimum Current Distortion for Symmetrical and Asymmetrical Multiphase Induction Motor Drives

A Generalized Overmodulation Strategy With Minimum Current Distortion for Symmetrical and Asymmetrical Multiphase Induction Motor Drives

Analysis of fault states in drive systems with multi-phase induction motors

Analysis of fault states in drive systems with multi-phase induction motors

Vector Control Technology of Five‐Phase Induction Motor without Speed Sensor Based on Speed‐Adaptive Full‐Order Observer

The five‐phase induction motor, being the most elementary form of multiphase induction motors, boasts low noise, low torque fluctuations, and high load‐bearing capacity, and is hence suitably employed in domains where high power and reliability are required. In light of the susceptibility of the speed encoder to interference from external environments, this paper proposes a sensorless vector control technique for the five‐phase induction motor based on a speed‐adaptive full‐order observer. The proposed approach first employs the nearest four‐vector space vector pulse width modulation (NFV‐SVPWM) as the modulation technique for the five‐phase inverter, in order to provide a constant switching frequency and low harmonic losses. Subsequently, the expression for the speed‐adaptive full‐order observer is constructed based on the mathematical model of the fundamental space of the five‐phase induction motor, and the expression for the adaptive speed law is deduced using the Lyapunov function. Additionally, the bilinear transformation method is utilized as the discretization technique for the full‐order observer during the process of digital implementation, in order to achieve higher discrete accuracy. Finally, an experimental study involving a 4.5 kW five‐phase induction motor was conducted to validate the accuracy and effectiveness of the proposed method. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

General Online Current-Harmonic Generation for Increased Torque Capability With Minimum Stator Copper Loss in Fault-Tolerant Multiphase Induction Motor Drives

This paper proposes a current-reference generation method including current harmonic injection (CHI) for enhancing the torque capability of multiphase induction machines (IMs) with negligible space-harmonic effects, which is useful, e.g., during transient overload in electric vehicles. The admissible torque is increased because the harmonics reduce the phase-current peaks, so that the instantaneous peak-current constraint of the drive, usually associated with the converter ratings, is respected. The harmonics are injected in the so-called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x-y</i> subspaces of the IM, which do not produce torque, so that no torque ripple is introduced. The optimum harmonics are found online for each load, making it possible to minimize the stator copper loss (SCL) per torque in the entire torque range, ensuring full-range minimum loss (FRML). The method is suitable for healthy operation or open-phase faults, and for multiphase machines of any phase number and with either symmetrical or asymmetrical windings. Compared with FRML methods without CHI, higher torque is achieved. Although some techniques were available for increasing the torque capability by CHI, FRML was not attained, laborious offline optimization was needed, or they were only suitable for specific drives or for healthy conditions, unlike the proposal. Experimental results with a symmetrical six-phase IM are provided.

Speed Estimation of Multiphase Induction Motor Using Rotor Slot Harmonics With Limited SNR and Dynamic Load Conditions

Accurate and reliable speed feedback is vital for closed-loop control of multiphase induction motors (IMs), especially in harsh operating scenes like ship propulsion. High performance speed estimation is effective in getting rid of usual sensor failures, through the rotor slot harmonic (RSH) based method that featured for parameter mismatch robustness. However, the accurate and real-time low speed estimation through RSHs under limited signal noise ratio (SNR) and dynamic load conditions is still a challenge, mainly due to the extremely weak and nonstationary amplitude and closely distributed frequency properties of RSHs. In this paper, we investigate the performance limitations of low speed estimation using primary rotor slot harmonics (PSH) of multiphase IMs, whose detectability is ensured through an improved interior detection coil, under limited SNR and dynamic load conditions. A frequency shifting and an amplitude limiting zero-crossing detection algorithm are proposed for efficient extraction and processing of PSHs in full speed range, which effectively improve the estimation accuracy with reduced complexity. Finally, the proposed method is investigated on a nine-phase IM experimental platform within the whole speed range, limiting the steady and transient error respectively under 4r&#x002F;min and 20r&#x002F;min for closed-loop control.

Vector-Controlled Dual Stator Multiphase Induction Motor Drive for Energy-Efficient Operation of Electric Vehicles

ABSTRACT This paper proposes an Indirect Field Oriented Controlled Dual Stator Multiphase Induction Motor (IFOC-DSMIM) as a traction unit in an Electric Vehicle (EV) for the enhancement of its fuel economy and average loading capacity. The performance of the drive is studied by loading it under standard drive cycles that include free running, acceleration, and braking conditions using the MATLAB/Simulink environment. Its performance analysis is carried out to obtain efficiency curves under the three modes of excitation using a steady-state equivalent circuit approach. Studies on load sharing between the two stators, speed tracking and torque-producing capability of the drive are executed on its dynamic model and the simulation results are depicted. The average energy efficiency of the vehicle with the proposed DSMIM drive system is at least 10% higher than a Single Stator Multiphase Induction Motor (SSMIM) drive under different load percentages. Furthermore, under 75% of rated load conditions the energy efficiency is 20% higher. Thus, the proposed DSMIM configuration promises to provide a sizeable energy saving in the EV system, reducing the energy cost and increasing the driving range.

Dual Closed-Loop Control Strategy on Harmonic Plane for Multiphase Induction Motor With Harmonic Injection Based on Air-Gap Flux Orientation Control

Multiphase motors, compared to three-phase motor, have many advantages, such as multiple degrees of freedom and flexible control. However, if these advantages are used incorrectly, it will increase the loss of the motor and decrease the efficiency. In response to this problem, this article lists the three limiting conditions that make the air-gap flux as quasi-trapezoidal waveform and analyzes the reasons why the traditional method cannot make the air-gap flux perfectly distributed. Therefore, a dual closed-loop feedback control structure on the harmonic plane was proposed. In this article, the feasibility and stability of the proposed method are analyzed. A series of comparative experiments on a seven-phase induction motor with concentrated windings platform is given. Finally, a conclusion that the proposed method not only can achieve a better electromotive force (EMF) waveform but also can increase torque per ampere is drawn.

Multiphase Induction Motor

Many researchers have studied multiphase Induction motor drives and output of these research shows that output Torque of these motors is superior to that of normal three phase Induction motor. Limitations on the power level of semiconductor devices establish a barrier to the increase of converter ratings. In order to get rid of this limitation, multilevel converters have been developed where switches of reduced rating are used to construct high power level converters. Instead of multilevel converters, multi-phase machines are used: By dividing the handled power between multiple phases, generally more than three, high power levels can be achieved even using limited rated power electronic converters. The aim of this research is to implement novel design and development of six phase induction motor. Also control of the same motor is carried out when fed by two, three phase inverters.

Enhanced Second-Order Sliding Mode Control Technique for a Five-Phase Induction Motor

Recently, several research papers have addressed multiphase induction motor (IM) drives, owing to their several benefits compared to the three-phase motors, including increasing the torque pulsations frequency and reducing the rotor harmonic current losses. Thus, designing a robust controller to ensure the proper operation of such motors became a challenge. The present study reports the design of an effective second-order sliding mode control (SO-SMC) approach for a five-phase IM drive. The proposed control approach finds its strongest justification for the problem of using a law of nonlinear control robust to the system uncertainties of the model without affecting the system’s simplicity. The formulation of the proposed SO-SMC approach is a prescribed process to ensure the stability and proper dynamics of the five-phase IM. A detailed stability analysis is also presented for this purpose. To validate the effectiveness of the proposed controller, the five-phase IM drive is tested under different dynamic situations, including load changes and system uncertainties. The presented numerical results prove the ability of the designed SO-SMC to handle high system nonlinearities and maintain high robustness against uncertainties.

Adaptive Online Extraction Method of Slot Harmonics for Multiphase Induction Motor

The accurate extraction and analysis of slot harmonics caused by slotting in an induction motor are important for the motor’s performance evaluation and state monitoring. However, the frequency distribution of rotor slot harmonics (RSHs) varies along with the operating states of the motor, such as motor speed and slip ratio, and the voltage and current signals of the motor only contain small-amplitude RSHs compared with other harmonics; both make it difficult to extract and analyze the RSHs accurately online. While offline extraction and filters with constant parameters are mainly utilized in available works, a novel adaptive extraction method for RSHs in a multiphase induction motor is proposed here to realize online RSH extraction under different speed and load conditions. In this paper, the RSHs in the multiphase induction motors are firstly modeled by using the magnetic potential permeability method, and the influence of a skewed rotor on RSHs is analyzed through a multisection method. Then, an adaptive extraction method of RSHs is proposed, which can effectively realize the online processing of RSHs of stator current. Finally, the experimental platform of a nine-phase induction motor has been used to verify the effectiveness of the proposed method under different speeds and load conditions, with a relative error of less than 1% in identifying the RSH frequency distribution.

An Improved PLL-Based Speed Estimation Method for Induction Motors through Harmonic Separation

The real-time speed estimation of induction motors (IMs) is important for the motors’ state monitoring and control. The utilization of rotor slot harmonics (RSHs) due to the inherent cogging effect is regarded as a promising way to realize the speed estimation of IMs. The key to the RSH-based speed estimation method is how to accurately and quickly identify the frequency of an RSH signal. However, as the RSH signal always consists of two side-frequency components that are adjacent to each other, it is actually improper to directly use the conventional phase-locked loop (PLL) method designed for single-frequency tracking. Furthermore, the form of the two side components in the frequency domain also leads to a significant amplitude fluctuation in the time-domain waveform of RSHs, thus resulting in the obvious frequency tracking errors of the conventional PLL method. In this paper, we proposed an improved PLL through harmonic separation to further improve the performance of the RSH-based speed estimation method of multiphase IMs, so that the dynamic tracking errors of PLL due to the reasons mentioned above can be significantly reduced. Simulations and experiments in a wide speed range were also performed, with their results presented as verifications of the proposed method.

Modelling and indirect field‐oriented control for pole phase modulation induction motor drives

In the recent days, for the traction and electric vehicle (EV) applications, multiphase machines with pole phase modulation (PPM) technique have been proposed. The smoother operation during pole changeovers as well as steady-state operations is a significant constraint while adopting the PPM-based multiphase induction motor (PPMIM) drives for EV and traction applications. So, in this paper, the PPMIM dynamic model and associated vector control are proposed for attaining a smoother operation of the machine. The machine modelling equations and transformation matrices are implemented in an arbitrary reference frame by considering the different pole phase combinations. Based on the modelling equations, the indirect field-oriented control (IFOC) is proposed for PPMIM drives by reflecting the associated changes in parameters for different pole phase modes. In the IFOC, for regulating the d-axis and q-axis current components, single PI control loops have been implemented for all pole-phase combinations. The proposed IFOC scheme is robust and applicable for adopting any type of pulse width modulation. The experimental, as well as simulation results, are given to illustrate the potentiality of the proposed dynamic model and IFOC. The PPMIM machine performance during the steady state as well as pole changeovers in different pole phase modes are analyzed and associated. Simulation and experimental results are presented.

Distributed Fault-Tolerant Powertrain Configuration for Electric Vehicle Applications With Pole-Phase Modulation

In Electric traction applications, the requirement of fault-tolerant survivability, better power/torque distribution, and highly efficient systems will helped to shift towards multiphase induction motors (MIM). For attaining the better fault tolerance of switch faults, many inverter configurations are established in the literature, however, these studies have not addressed the multiple switch faults in different inverter legs. Moreover, for the source fault of the multiphase drive, the entire system has to be halted. In this paper, a distributed powertrain structure is proposed for Electric traction applications to fulfill the gaps in the aforementioned critical issues. A Fault-tolerant multiphase inverter (FTMI) fed nine-phase induction motor (NPIM) drive is proposed with a lesser number of auxiliary components like switches and fuses. The proposed FTMI has effectively utilized the concept of pole phase modulation for NPIM, which helps in operating the drive at two possible modes (9phase 4pole and 3phase 12pole). With this additional flexibility of PPM, the proposed FTMI fed NPIM drive is capable to operate with full load power during the single/multiple switch open/short circuit faults and source faults contrary to the existing techniques. The practicability of the proposed FTMI fed NPIM drive is validated by performing various experiments.

Dynamic Modeling and Control of Pole-Phase Modulation-Based Multiphase Induction Motor Drives

Pole-phase modulation based multiphase induction motor (PPMIM) drives possess the capability of providing an extended range of speed-torque for high power traction application with the available additional degrees of freedom in the multiphase machine. As observed in previous open-loop results of PPMIM drives presented in the literature, the transient currents often exceed twice the rated currents. To address this issue, this paper focuses on the modelling and advanced control of the PPMIM drives during all possible pole-phase combinations. The dynamic mathematical modelling of the PPMIM in actual phase variable domain is presented in detail. Since this model involves time-dependent inductances and torque, the machine model equations are transformed into dq domain using transformation matrices. The transformation matrices, modelling equations in the arbitrary reference frame and multiphase inverter are modelled by considering all parameters of possible pole-phase combinations. Based on the proposed modelling equations, an indirect field oriented control (IFOC) is implemented for PPMIM drives for smoother operation in all possible modes of operation. The modelling equations, as well as IFOC of PPMIM drive, are implemented in MATLAB to illustrate the behaviour of machine during transients as well as different load torques. The proposed concepts are also validated on laboratory setup and the hardware results are demonstrating the smoother transition as well as steady state operation of PPMIM drive in pole changeovers as well as both pole-phase combinations.

Multiphase Stator Winding: New Perspectives, Advanced Topologies, and Futuristic Applications

Multiphase winding configurations have gained significant attention in high-performance variable speed drives and wind energy conversion systems (WECS) owing to their myriad advantages. In the available literature, various multiphase winding layouts have been designed aiming at boosting the machine performance to meet the requirements of the proposed applications. Ultimately, this paper surveyed the state-of-the-art in the available multiphase winding layouts proposed for various innovative applications. Various types of windings were discussed, while investigating their advantages and limitations. This typically considers the winding layouts employed in multiphase induction motors (IMs) and permanent magnet (PM) machines with prime phase and multiple three-phase orders. This study extensively provides innovative winding arrangements that offer better machine characteristics in terms of torque density, efficiency, and fault-tolerance capability. Moreover, the construction of multiphase machines with general <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -phase using standard three-phase stator frames has been elaborated. This latter technique obviates the basic necessity of special stator frames with a prime number of phases. Finally, this paper sheds light on the commercial applications that include multiphase winding layouts.

Space Vector PWM Based DTC Scheme With Reduced Common Mode Voltage for Five-Phase Induction Motor Drive

In multiphase induction motor drives, lowering the common-mode voltage (CMV) reduces motor insulation degradation and the existence of destructive bearing current. For this investigation, a five-phase two-level voltage source inverter (FPTL-VSI) fed five-phase induction motor (FPIM) drive is used. FPTL-VSI produces increased CMV, which cannot be totally removed. Moreover, CMV can be reduced by 80% in contrast to its peak-to-peak value with suitable selection of small and large voltage vectors in a space vector pulsewidth modulation (SVPWM) scheme. Direct torque control (DTC) combined with the SVPWM scheme can accomplish such reduced CMV performance at constant switching frequency. To provide better speed and torque control, two virtual vector (VV) based SVPWM-DTC (DTC1 and DTC2) methods are proposed in this study. Over a wide range of modulation index, the influence of each voltage VV on motor drive speed and torque response is investigated. The proposed DTC1 and DTC2 schemes are validated under steady-state and dynamic conditions over a wide range of speed fluctuations using a high-power laboratory prototype of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3.8\,\text{{k}W}$</tex-math></inline-formula> FPIM drive. The efficacy of the proposed DTC1 and DTC2 is compared to the current literature by evaluating the effectiveness of CMV and the switching frequency.

COMPARATIVE ANALYSIS OF SIX PHASE INDUCTION MOTOR

In recent years, AC induction motors have replaced DC motor. The most important reason for this is that DC motors have a mechanical brush and commutator system that is subject to wear and tear over time. While DC motor drivers need a lot of maintenance due to this system, induction motors do not require almost any maintenance since this system is not available. In recent years, technological advances in the field of multiphase induction motors have led to a significant evolution. A lot of research has been done around the world and a lot of new and interesting developments have been reported to the literature. This paper provides information about six-phase induction. In addition, what kind of advantages the concept of multiphase provides and how this structure is formed contains information about them. The six-phase induction motor will be simulated through the MATLAB/SIMULINK package program and compare with three phase induction motor. Both motors were run in simulation using the same parameters. At the end of the simulation, current, moment and speed graphs of the six-phase induction motor and three-phase induction motor will be drawn according to time. The study also included equations used during modeling and equivalent circuits belonging to a six-phase induction motor. It has been graphically shown that a six-phase induction motor is more advantageous than a three-phase motor. For example, in six-phase induction motors, the transition time to a continuous state is shorter. In addition, while the frequency of torque vibration increases, its amplitude decreases, the current value of each phase decreases, the stator copper losses are less than the three-phase induction motor. In motors, usually the power needed is divided by the number of phases. So the more phases there are, the greater the power carrying capacity. Today, multi-phase induction motor drives are used in special applications such as electric vehicles, space technology, aerospace applications, as moving power on ships, electric trains, which require high reliability and power.

Applicability Analysis of Indices-Based Fault Detection Technique of Six-Phase Induction Motor

The multiphase induction motor is considered to be the promising alternative to the conventional three-phase induction motor, especially in safety-critical applications because of its inherent fault-tolerant feature. Therefore, the attention of many researchers has been paid to develop different techniques for detecting various fault types of multiphase induction motors, to securely switch the control mode of the multiphase drive system to its post-fault operation mode. Therefore, several fault detection methods have been researched and adapted; one of these methods is the indices-based fault detection technique. This technique was firstly introduced to detect open-phase fault of multiphase induction motors. The main advantage of this technique is that its mathematical formulation is straightforward and can easily be understood and implemented. In this paper, the study of the indices-based fault detection technique has been extended to test its applicability in detecting some other stator and rotor fault types of multiphase induction motors, namely, open-phase, open-switch, bad connection and broken rotor bar faults. Experimental and simulation validations of this technique are also introduced using a 1 kW prototype symmetrical six-phase induction motor.

Electronic Pole-Changing Strategy with Cosine-Response for Multiphase Induction Motor Based on PR Controller

Electronic Pole-Changing Strategy with Cosine-Response for Multiphase Induction Motor Based on PR Controller

Fuzzy logic based dynamic performance enhancement of five phase induction motor under arbitrary open phase fault for electric vehicle

Abstract The multiphase induction motor can be a highly preferable choice for the EV application, where the reliability and safety of passengers are one of the major concerns. The main objective of this article is to design high performance fault tolerant control of five phase induction motor (FPIM) drive to enhance the dynamic performance under healthy, faulty and fault tolerant modes of operation under arbitrary open phase fault condition. First, a simple method of modeling open phase fault in any phase of the FPIM drive is proposed. The most frequently occurring open phase faults due to the power electronics switch failure in the inverters are considered for the analysis. A generalized method of modeling arbitrary open phase fault in FPIM drive using back EMF calculations in faulty phase is suggested. The developed method utilizes the same transformation matrix for any open phase fault such that the minimum modification in control strategy is required under fault condition. Thereafter, the control technique is detailed. The rotor field oriented control (RFOC) of FPIM with fuzzy logic speed controller is developed to generate optimal torque reference. The design of FLC is detailed with fine-tuned scaling factor, rule base and membership function to obtain robust performance of the drive under healthy and fault tolerant modes of operation. The complete RFOC scheme for 2 HP FPIM drive is built in MATLAB/SIMULINK incorporating fuzzy logic based controller to verify its performance. The comparison of transient and steady state response and robustness (to the load disturbance as well as fault) obtained using developed fuzzy logic based controller with those using conventional PI controller is presented to prove the efficiency of the suggested controller under various speed torque profiles. The effectiveness of the proposed fuzzy based fault tolerant controller for FPIM drive is validated using OP4510 controller based real time HIL simulator.