Optimal Modeled Six-Phase Space Vector Pulse Width Modulation Method for Stator Voltage Harmonic Suppression

Dual Y shift 30 six-phase motors are expected to be extensively applied in high-power yet energy-effective fields, and a harmonic-suppressing control strategy plays a vital role in extending their prominent features of low losses and ultra-quiet operation. Aiming at the suppression of harmonic voltages, this paper proposes a six-phase space vector pulse width modulation method based on an optimization model, namely OM-SVPWM. First, four adjacent large vectors are employed in each of 12 sectors on a fundamental sub-plane. Second, the optimization model is constructed to intelligently determine activation durations of the four vectors, where its objective function aims to minimize the synthesis result on a harmonic sub-plane, and its constraint condition is that the synthesis result on the fundamental sub-plane satisfies a reference vector. Finally, to meet the real-time requirement, optimum solutions are obtained by using general central path following algorithm (GCPFA). Simulation and experiment results prove that, the OM-SVPWM performs around 37% better than a state-of-the-art competitive SVPWM in terms of harmonics suppression, which promise the proposed OM-SVPWM conforms to the energy-effective direction in actual engineering applications.Peer reviewe

Investigation of rotor position detection schemes for PMSM drives based on analytical machine model incorporating nonlinear saliencies

University of Technology, Sydney. Faculty of Engineering and Information Technology.This thesis presents the essential and new improvements of the machine modelling and drive-strategies for permanent magnet synchronous machines (PMSMs), including the rotor position sensorless drive schemes. Many important issues about PMSM drive schemes, from the modelling to drive design have been investigated from the machine model point of view. A comprehensive PMSM model incorporating both structural and magnetic saturation saliencies has been developed and expressed numerically and analytically. Highly efficient rotor position detection method has been developed based on the new machine model. The traditional mathematical model of PMSM is investigated at the beginning of this thesis for the conventional PMSM drive schemes, including six-step control, field oriented control (FOC) and direct torque control (DTC). The fundamental principles and improvements of the drives are summarized based on the machine model. Performance companson is conducted for djfferent schemes and an improved DTC scheme is developed. PMSM drive without rotor position sensor, or so called sensorless drive, is a desired feature for the electrical servo systems and automotive applications. The Jack of accurate nonlinear machine model L the bottle neck for highly efficient sensorless drive development. Experiment trial and error attempts have to be employed to design rotor position detection schemes. On the other hand, there is not a comprehensive machine model to assess the sensorless drive performance. The inaccuracies associated with the conventional PMSM model have been discussed in this thesis. The saliencies in PMSM utilized for rotor position tracking are classified as two types, the structural saliency and the magnetic saturation saliency. The nonlinear saturation saliency cannot be modelled in the conventional PMSM model. However, it is essential for the rotor position estimation, especially the initial rotor position detection. A composite function is designed to express the inductances of PMSM, incorporating the nonlinear saturation saliency. Experimentally collected inductance data are used to regress the parameter matrix and a numerical PMSM model is developed. It is then proved that the structural and saturation saliencies can be decoupled analytically and expressed separately. The concepts, structural saliency ratio and saturation saliency ratio are defined to indicate the magnetic saliency in PMSMs. The analytical mathematic machine model incorporates the nonlinear behaviour of the magnetic field of PMSMs. The proposed model is validated by the experimentally collected data. Based on the developed analytical nonlinear machine model, a DC voltage pulse injection based initial rotor position detection scheme is designed and implemented. Thanks to the comprehensive machine model, improved injection scheme is designed to minimize the rotor vibration and increase the estimation speed. Simulation and experiment of the novel detection method are conducted to verify the estimation accuracy. Finally the proposed model is applied to analyse the sensorless drive schemes for PMSMs. The investigation focuses on high frequency signal injection based sensorless methods. A new inj ection method is proposed based on the machine model, in which the carrier signal is injected on a fixed stator spatial direction. The proposed sensorless method and other reported sensorless schemes are compared based on both machine model and simulation. According to the non1inear machine model, generalized indicators are defined to express the drive performance, computing cost and estimation efficiency, which provide a comprehensive assessment for sensorless drive schemes of PMSM

Permanent-Magnet Synchronous Machine Drives

The permanent-magnet synchronous machine (PMSM) drive is one of best choices for a full range of motion control applications. For example, the PMSM is widely used in robotics, machine tools, actuators, and it is being considered in high-power applications such as industrial drives and vehicular propulsion. It is also used for residential/commercial applications. The PMSM is known for having low torque ripple, superior dynamic performance, high efficiency and high power density. Section 1 deals with the introduction of PMSM and how it is evolved from synchronous motors. Section 2 briefly discusses about the types of PMSM. Section 3 tells about the assumptions in PMSM for modeling of PMSM and it derives the equivalent circuit of PMSM. In Section 4, permanent magnet synchronous motor drive system is briefly discussed with explanation of each blocks in the systems. Section 5 reveals about the control techniques of PMSM like scalar control, vector control and simulation of PMSM driven by field-oriented control using fuzzy logic control with space vector modulation for minimizing torque ripples. PMSM control with and without rotor position sensors along with different control techniques for controlling various parameters of PMSM for different applications is presented in Section 6

Serangga dan mitos suku kaum jakun, Kampung Peta, Mersing Johor

This study focuses on seeing insects from the mythical perspective of the Orang Asli tribe of Jakun, Kampung Peta, Mersing Johor. The existence of insects in the life of every ethnic in Malaysia has brought various elements of myths. Therefore, when combining myths and insects, it could be said that myth is a human way of understanding, expressing and linking insects to him/herself as well as a group/culture. The practice of using insects among ethnic groups in daily life is called etnoentomology. In this study, the insects studied are the butterfly (Lepidoptera), the odonates (Odonata) and the cicadas (Homoptera). This is because these insects are very popular in the community and have their own myths that are brought into the local culture of belief

Comparison of Interior Mounted Permanent Magnet Synchronous Motor Drives with Sinusoidal, Third Harmonic Injection, and Space Vector Pulse Width Modulation Strategies with particular attention to Current Distortions and Torque Ripples

Interior Mounted Permanent Magnet Synchronous Motors (IPMs) have become popular in electric vehicle traction applications in recent years due to their superior features such as high efficiency and high power density compared to other machines. Therefore, development of IPM drive systems is an important research area. In this study, three different pulse width modulation (PWM) strategies commonly used in machine drives are compared extensively in IPM drives. Simulations have been carried out with optimum dq-axes currents based on demanded torque from the system, and hence, the simulated drives are efficiency-optimized. Sinusoidal pulse width modulation (SPWM), third harmonic injection pulse width modulation (THIPWM), and space vector pulse width modulation (SVPWM) strategies have been employed in the drives, and comparisons have been made by paying particular attention to the total harmonic distortion (THD) rates of phase currents and torque ripples. It has been validated through extensive simulations that the SVPWM strategy has less THD percentage for IPM drives than SPWM and THIPWM at wide operating points, and hence, the current and torque responses are better with smooth output torque. Simulation results also validate that the current distortions and torque ripples are the highest when SPWM strategy is adopted in the drives, and hence, the THIPWM strategy is superior to the SPWM. © 2023 Istanbul University. All rights reserved

ANFIS based Direct Torque Control of PMSM Motor for Speed and Torque Regulation

Nowadays, the Permanent Magnet Synchronous Motors (PMSM) are gaining popularity among electric motors due to their high efficiency, high-speed operation, ruggedness, and small size. PMSM motors comprise a trapezoidal electromotive force which is also called synchronous motors. Direct Torque Control (DTC) has been extensively applied in speed regulation systems due to its better dynamic behavior. The controller manages the amplitude of torque and stator flux directly using the direct axis current. To manage the motor speed, the torque error, flux error, and projected location of flux linkage are employed to adjust the inverter switching sequence via Space Vector Pulse Width Modulation (SVPWM). One of the most common problems encountered in a PMSM motor is Torque ripple, which is recreated by power electronic commutation and a better controller reduces the ripples to increase the drive's performance. Conventional controllers such as PI, PID and SVPWM-DTC were compared with the proposed Adaptive Neuro-Fuzzy Inference System (ANFIS) in terms of performance measures such as speed and torque ripple. In this work, the Two-Gaussian membership function of the ANFIS controller is used in conjunction with a PMSM motor to reduce torque ripple up to 0.53 Nm and maintain the speed with a distortion error of 2.33 %

The investigation of electromagnetic radial force and associated vibration in permanent magnet synchronous machines

The rising public awareness of climate change and urban air pollution has been one of the key drivers for transport electrification. Such trend drastically accelerates the quest for high-power-and-torque-density electric drive systems. The rare-earth permanent magnet synchronous machine, with its excellent steady-state and dynamic characteristics, has been the ideal candidate for these applications. Specifically, the fractional-slot and concentrated-winding configuration is widely adopted due to its distinctive merits such as short end winding, low torque pulsation, and high efficiency. The vibration and the associated acoustic noise become one of the main parasitic issues of high-performance permanent magnet synchronous drives. These undesirable features mainly arise from mechanical connection failure, imperfect assembly, torque pulsation, and electromagnetic radial and axial force density waves. The high-power-and-torque-density requirement will only be ultimately fulfilled by the reduction of both electromagnetic active material and passive support structure. This results in inflated electromagnetic force density inside the electric machine. Besides, the sti.ness of the machine parts can be compromised and the resultant natural frequencies are significantly brought down. Therefore, the vibration and acoustic noise that are associated with the electromagnetic radial and axial force density waves become a burden for large deployment of these drives. This study is mainly dedicated to the investigation of the electromagnetic radial forced density and its associated vibration and acoustic noise in radial-flux permanent magnet synchronous machines. These machines are usually powered by voltage source inverter with pulse width modulation techniques and various control strategies. Consequently, the vibration problem not only lies on the permanent magnet synchronous machine but also highly relates to its drive and controller. Generally, the electromagnetic radial force density and its relevant vibration can be divided into low-frequency and high-frequency components based on their origins. The low-frequency electromagnetic radial force density waves stem from the magnetic field components by the permanent magnets and armature reaction of fundamental and phase-belt current harmonic components, while the high-frequency ones are introduced by the interactions between the main low-frequency and sideband highfrequency magnetic field components. Both permanent magnets and armature reaction current are the main sources of magnetic field in electric machines. Various drive-level modeling techniques are first reviewed, explored, and developed to evaluate the current harmonic components of the permanent magnet synchronous machine drive. Meanwhile, a simple yet e.ective analytical model is derived to promptly estimate the sideband current harmonic components in the drive with both sinusoidal and space-vector pulse width modulation techniques. An improved analytical method is also proposed to predict the magnetic field from permanent magnets in interior permanent magnet synchronous machines. Moreover, a universal permeance model is analytically developed to obtain the corresponding armature-reaction magnetic field components. With the permanent magnet and armature-reaction magnetic field components, the main electromagnetic radial force density components can be identified and estimated based on Maxwell stress tensor theory. The stator tooth structure has large impacts on both electromagnetic radial force density components and mechanical vibration behaviors. The stator tooth modulation e.ect has been comprehensively demonstrated and explained by both finite element analysis and experimental results. Analytical models of such e.ect are developed for prompt evaluation and insightful revelation. Based on the proposed models, multi-physics approaches are proposed to accurately predict low-frequency and high-frequency electromagnetic radial vibration. Such method is quite versatile and applicable for both integral-slot and fractional-slot concentrated-winding permanent magnet synchronous machines. Comprehensive experimental results are provided to underpin the validity of the proposed models and methods. This study commences on the derivations of the drive parameters such as torque angle, modulation index, and current harmonic components from circuit perspective and further progresses to evaluate and decouple the air-gap magnetic field components from field perspective. It carries on to dwell on the analytical estimations of the main critical electromagnetic radial force density components and stator tooth modulation e.ect. Based on the stator mechanical structure, the corresponding electromagnetic radial vibration and acoustic noise can be accurately predicted. Various analytical models have been developed throughout this study to provide a systematic tool for quick and e.ective investigation of electromagnetic radial force density, the associated vibration and acoustic noise in permanent magnet synchronous machine drive. They have all been rigorously validated by finite element analysis and experimental results. Besides, this study reveals not only a universal approach for electromagnetic radial vibration analysis but also insightful correlations from both machine and drive perspectives

Guiding paving block porous for blind people

Porous concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates (sand). That is a mixture of cement, water and coarse aggregate. Use of the guiding paving block porous for blind people is one of the efforts that will be made to overcome the inundation due to water spills from sufficiently high rainfall, providing comfort and safety for users so as not to slip easily due to slippery road surfaces, that will be used must have a measurable value of permeability and porosity to optimize the function of using porous concrete. Guiding paving block porous for blind people are very economical and have a great advantage in absorbing water so the surface is always dry, and can reduce accidents due to slippery roads. Another advantage is that the product is environmentally friendly with handmade, designed using a mixture of plastic bottle waste material can be made apart from the manufacturing process in various shapes and various colors. From the test results it has a strength of 10-15 mpa in the precast age of 28 days with a water absorption capability of up to 10L / m2

Development of FPGA based control architecture for PMSM drives

University of Technology Sydney. Faculty of Engineering and Information Technology.The rapid advancement of the very large scale integration (VLSI) technology and electronic design automation techniques in recent years has made a significant impact on the development of complex and compact high performance control architecture for industrial motion systems. Specific hardware with the field programmable gate array (FPGA) technology is now considered as a promising solution in order to make use of the reliability and versatility of controllers. Indeed, FPGAs have been successfully used in many control applications such as power converter control and electrical machines control. This is because such an FPGA-based implementation can offer an effective reprogrammable capability and overcome disadvantages of microprocessor-based or digital signal processor-based embedded systems. This thesis aims to provide a proof-of-concept for the control-system-on-chip and a prototype for a fully-implemented FPGA control architecture for permanent magnet synchronous motor (PMSM) drives. In this thesis, a special focus is given on analytical effects, design procedure, and control performance enhancement for PMSM drives under sensor/sensorless vector control using a number of control techniques. The control schemes include FPGA-based intelligent control and robust cascade control for single axis and multiple axis tracking with PMSMs. An important contribution of this thesis rests with a convincing demonstration of high performance estimation schemes, using sliding mode observers and extended Kalman filters, in terms of accuracy and robustness against noisy and/or perturbed currents for sensorless PMSM control based on the FPGA technology. In addition, a sequential finite state machine is developed in this work to result in less logic gate resources, leading to a faster processing time. Significance of this thesis contribution includes in providing a feasible and effective solution for the implementation of complex control strategies to fully exploit the FPGA advantages in power electronics and drive applications