Electric motor drives Research Papers (original) (raw)

Motors are the most important driving components of industrial and consumer products. Therefore improving the energy efficiency of their work is an important environmental and economic problem. Systematic review of laboratory equipment for training in energy efficiency is made for the integrated influence between curricular practical training and current requirements of the industry. The application of various training tools opens up new possibilities for adapting the teaching methods in universities to the learning style of today’s students. The presented system is improved with application of additional software and hardware components from other manufacturers.

The aim behind the development of the project is to limit the current at starting of motor and to develop the high starting torque. There are different methods of starting of 3-phase Slip-Ring induction Motor. However, we selected the rotor resistance method of control for Starting the Induction Motor. Here a Programmable Logic Controller is used which will be programmed as per our need. We have designed a control panel and programmed the PLC according to our need. The motor starts with high rotor resistance and as time elapse the rotor resistance will be shorted and the motor runs at rated speed. The resistance has been cut from the rotor in three parts in three different time intervals. The process of management of time and controlling of relays is the function of the PLC. Depending on PLC output, the relays will get shorted and the resistance will be removed from the rotor terminal.

- by SriKanth T
- •
- Electrical Engineering, Motor Control, Industrial Engineering, Electric motor drives
- by Quinn Sullivan
- •
- Electric Vehicles, Electric motor drives, Electrical Motors, Lithium-Ion Battery

Direct torque control (DTC) of AC drives is considered one of the most interesting
high performance control techniques nowadays. Permanent magnet synchronous motors
(PMSM) are now replacing induction motors (IM) in a variety of applications due to
their valuable characteristics especially the increased efficiency and compact size. The
combination of DTC and PMSM in one drive system leads to high dynamic response
drive system that seems to be an interesting topic to gain the increased research in the
literature.
DTC offers high dynamic torque, flux, and speed responses better than that of Field
Oriented Control (FOC) technique with simple controller architecture that utilizes two
hysteresis controllers and a switching table to select the most suitable voltage vector to
meet the torque and flux requirements. No machine parameter dependences, no axes
transformation required, no voltage modulation techniques, and no current controllers
are the advantages of DTC over FOC. Comparisons between DTC and FOC of PMSM
are made through MATLAB simulations to show their characteristics with respect to
the other. It is found that DTC gives excellent dynamic responses in both torque and
flux but the ripple content is high.
DTC requires the estimation for both flux and torque. A lot of methods are found in
the literature to estimate the flux and the most powerful methods are compared via
simulations. Pure integration method of flux estimation is the basic method that has a
lot of demerits like offset, resistance variation dependence, initial value problem, and
low performance at low speeds. Low Pass Filter (LPF) is intended to solve the pure
integration problems but its performance at transient period is not good and there is
some drift in the flux beyond the actual flux. Modified integrator is also one of the
interesting flux estimation methods that gives better performance at both transient and
steady state conditions than that of LPF estimator but it contains PI controller and low
pass filters so that several tunings are required and complexity is increased. A flux
estimator uses tunable-cutoff-frequency-LPF is simple and accurate. It is used for IM
and never be used for PMSM. It is also compared and shows excellent results in both
transient and steady state periods which implies the effectiveness of it for PMSM as
well as IM.
Switching Look-up Table is a unique characteristic in a DTC drive and it has a lot of
schemes based on the number of hysteresis levels of the torque and flux comparators
and the inclusion / exclusion of the zero voltage vectors. Various switching tables
appeared in the literature are compared to judge the merits and demerits of each one
and to show their effect on the drive performance. A relatively new switching table
using modified definition of the flux sectors is used for PMSM for the first time and its
results are excellent because it avoids a fatal problem appeared in the table proposed by
Takahashi, the inventor of the DTC system.
Selection of the amplitude of the flux and torque hysteresis bands is a very
important issue in implementing the DTC drive system as they affect torque ripples,
flux distortion, switching losses, and current harmonics. Simulations are made to
show these effects. Trade off should be made to correctly choosing of the
hysteresis band amplitudes according to the performance requirements.
Torque / flux ripples and variable switching frequency are the main disadvantages of
DTC system. Solutions to these problems are an interesting researching aspect
nowadays. Increased number of voltage vectors and/or sectors, Space Vector
Modulation (SVM), Duty Ratio control, and Model Predictive Control (MPC)
techniques are the most common solutions to the problems of high ripple content and
variable switching frequency. The loss of the DTC simplicity is something that makes
these solutions inconvenient so that compromise studies should be done to select the
most suitable control technique that meets the application needs without increasing the
complexity of the system.
Digital Signal Processors (DSPs) are now considered the basic controllers used in
the motor control area. DSP programming is often done using hand written code by C
or Assembly languages which is very time consuming and very prone to errors.
Computer Aided Control System Design (CACSD) is some sort of block programming
can be implemented using Matlab/Simulink. The Simulink model itself can be
downloaded to the DSP which makes the real time control system design easier.
The complete description of the DTC-PMSM drive system is discussed showing the
power, control, measurement, and signal conditioning circuits used in the system. Six
step operation of the inverter as well as open loop V/F control of PMSM are
implemented in order to verify the effectiveness of the CACSD using Matlab/Simulink.

- by Mohiuddin Mahbub
- •
- Motor Control, Electric motor drives, Ac motor modeling

According to the Mines and Energy Minitry of Brazil the national industry spends 43,7% of all energy of the country, electrical motors are the responsible for 68% of all energy spend of the industries, what means that it is equivalent near to 30% of the energy of Brazill. It takes people to think about energy efficiency of electric motors in general. As the frequency inverters rised as equipaments that brings more energy efficiency in the electricity usage in motor drives, nowadays the electric engineering is looking for other alternatives to improve this and with this ideia the industry has been paying an especial attention in permanent magnet motors, due its high efficiency and performance. The growth of the market of permanent magnet motors is recent but already exist good numbers. As seen in a research of Markets and Markets there is a forecast to permanent magnet motors market of the Brushless DC motor type to enrich in 8,15 millions of dollars into 2021. According to Global Newswire economic leaders like EUA e countries of western Europe had a recent resumed of growth in the manufacturing sector that incorporated a good number of permanent magnet motors and helped with its popularization, still according to the same source, the biggest market of permanent motor is in Pacific-Asia, where are located countries like China, India, South Korea and Japan. Moreover, is notable the rising of electric cars in the automotive market around the world and permanent magnets have a fundamental place in developing these cars. The present work has a dissertation about the vector control of the permanent magnet synchronous motor, starting with a general review of this motor and following a theoretical revision of the vector control concept in a generic way and then adapting this vector control to the permanent magnet synchronous motor, considering its specificities, to finally achieve the drive model by vector control of this motor. A model of vector control drive of permanent magnet motor will be used for simulation in SIMULINK tool of software MATLAB.
Key-words: PMSM, PMAC, Permanet Magnet Motors Drivers, Vector Control, FOC

- by Patrick Rafael Andrade
- •
- Motor Control, Electric motor drives, Control Systems, Ac Motors Drives

Motor listrik adalah alat untuk mengubah energy listrik menjadi energy mekanik. Begitu juga dengan sebaliknya yaitu alat untuk mengubah energy mekanik menjadi energy listrik yang biasanya disebut dengan Generator atau dynamo. Motor listrik dapa tkita temukan di peralatan rumahtangga seperti: kipas angin, mesin cuci, Blender, pompa air, mixer dan penyedot debu. Adapun motor listrik yang digunakan untuk kerja (industry) atau yang digunakan dilapangan seperti: bor listrik, gerinda, blower, menggerakan kompresor, mengangkat bahan,dll. Pada motor listrik yang tenaga listrik di ubah menjadi tenaga mekanik. Perubahan ini dilakukan dengan mengubah tenaga listrik menjadi magnet yang disebutsebagai elektro magnet. Sebaga imana yang telah kita ketahui bahwa kutub – kutub dari magnet yang senama akan tolak menolak dan kutub yang tidak senama akan tarik menarik. Dengan terjadinya proses ini maka kita dapat memperoleh gerakan jika kita menempatkan sebuah magnet pad asebuahporos yang dapatberputar dan magnet yang lain pada suatu kedudukan yang tetap.

The field oriented control theory and space vector pulse width modulation technique make a permanent magnet synchronous motor can achieve the performance as well as a DC motor. However, due to the nonlinearity of the permanent magnet synchronous motor drive characteristics, it is difficult to control by using conventional proportional-integral-derivative controller. By this reason in this paper an online neural network controller for the permanent magnet synchronous motor is proposed. The controller is designed to tracks variations of speed references and also during load disturbance. The effectiveness of the proposed method is verified by develop simulation model in MATLAB-simulink program. The simulation results show that the proposed controller can reduce the overshoot, settling time and rise time. It can be concluded that the performance of the controller is improved.

- by wa hyu
- •
- Power Electronics, Electric motor drives

—This paper presents development of energy-efficient and fault-tolerant control of multiphase nonsinusoidal PM synchronous machines by making use of the Hamiltonian of optimal control theory. An analytical solution for the optimal-linearization control is derived in a closed-form from the maximum principle formulation to linearize the machines and at same time to maximize machine efficiency for non-constant operational torque and speed while automatically deferring output voltage saturation. The controller can achieve voltage-to-torque linearization even for faulty motors with open-circuited phase(s) making it suitable for high-risk applications. This work is complemented by presenting an optimal indirect-torque control scheme based on internal current feedback loop with finite bandwidth. Simulation and experimental results are appended to underpin the performance of the energy-efficient and fault-tolerant controller.

- by Farhad Aghili
- •
- Robotics, Optimal Control, Motor Control, Motion control

This paper presents a modified space vector pulse width modulation to drive permanent synchronous motor, the switching pattern of modified space vector pulse width modulation (MSVPWM), with certain notches, in the switching pattern of conventional type, are eliminated. These notches at relatively high modulation index have small width compared with switching period. The modified strategy has many features, such as increasing the utilization of dc input voltage and therefore higher output voltage, reducing the stress on power switches, and reducing switching power losses. The percentage reduction in the number of pulses for each switch device is about 33% of total number of switching pattern. This is due to the nature of space vector pulse width modulation. The proposed approach is analyzed and simulated, using Matlab Simulink . The obtained results prove that the proposed strategy has low power switching losses, and higher fundamental range and good quality of output voltage waveform compared with conventional space vector. Practical results have been obtained which validate the theoretical and simulation approaches.

- by laith Mohammed and +1
- •
- Power Electronics, Electric motor drives

The fast developments in power electronic
technology have made it possible to mitigate voltage disturbances
in power system. Among the voltage disturbances challenging the
industry, the voltage sags are considered the most important
problem to the sensitive loads. Dynamic voltage restorer (DVR) is
a series connected power electronic based device that can quickly
mitigate the voltage sags in the system and restore the load
voltage to the prefault value. DVR is recognized to be the best
effective solution to overcome this problem. The primary
advantage of the DVR is keeping the users always on-line with
high quality constant voltage maintaining the continuity of
production. In this paper, the usefulness of including DVR in
distribution system for the purpose of voltage sag and swell
mitigation is described. The DVR presented here is based on the
concept of dqo. The proposed control method is found very
efficient for detecting and clearing any power quality disturbance
in distribution systems. Results of simulation using Matlab-
Simulink are demonstrated to prove the usefulness of this
scheme.

- by Tomson Thomas and +1
- •
- Electric motor drives

Use of Electric Vehicles is increasing due to zero carbon emission,its sustainability and energy saving capability.This paper compares performance,efficiency and reliability of different motors which can be used as drive train of electric vehicles.Performance of Induction Motors,Brushed DC Motors,Permanent Magnet Brushless DC Motors,Switched Reluctance Motors and their respective controller have been simulated.Merits and demerits of each system have been highlighted.Performance of BLDC and switched reluctance motors as in-wheel motors under normal and critical conditions are compared.The paper also covers the additional benefits of integration of BLDC motor-drive systems with inbuilt adaptation of control and self fault diagnosis in-wheel systems.

- by ALIREZA TASHAKORI ABKENAR
- •
- Electric Vehicles, Electric motor drives
- by John Lh
- •
- Mechanical Engineering, Electric Vehicles, Electric motor drives, Li ion Batteries

Sinusoidal pulse width modulation is a popular
modulation for most alternating current induction motor. It
only requires fewer calculations and is easy to implement.
However, the shortcomings of using it are low DC voltage
utilization, and poor inverter transmission capability. In
recent years, there is an increasing trend and more research
concentration of using space vector pulse width modulation
in adjustable speed drives and renewable energy systems
because it has better DC bus utilization, better performance,
lower loss, lower ripples, and wide application range. This
paper introduces space vector pulse width modulation and
applies to speed control of alternating current induction
motor. The three phase alternating current induction motor
is reviewed based upon space vector representation. The
development of space vector pulse width modulation and
implementation to speed control of induction motor is done
using Matlab/Simulink. The simulation is conducted by
analyzing the response of stator current, stator voltage,
speed, voltage, frequency, and the electromagnetic torque.
Simulation results shows that space vector pulse width
modulation which generates the voltage patterns at real time
is able to control the speed of a three phase alternating
current induction motor. It indicates the validity of space
vector pulse width modulation in controlling the speed of a
three phase alternating current induction motor (ACIM). In
conclusion, the use and realization of space vector pulse
width modulation has been validated by the Matlab/Simulink
simulation experiment for controlling the speed of a three
phase alternating current induction motor.

- by Angelo Beltran Jr.
- •
- Motor Control, Modeling and Simulation, Electric motor drives, Simulation
- by Prof. Dr. Saad Mekhilef
- •
- Engineering, Power Electronics, Topology, Electric motor drives

Wide bandgap (WBG) device-based power electronics converters are more efficient and lightweight than Silicon-based converters. WBG devices are an enabling technology for many motor drive applications and new classes of compact and efficient motors. This paper reviews the potential applications and advances enabled by WBG devices in ac motor drives. Industrial motor drive products using WBG devices are reviewed and the benefits are highlighted. This paper also discusses the technical challenges, converter design considerations and design trade-offs in realizing the full potential of WBG devices in motor drives. There is a trade-off between high switching frequency and other issues such as high dv/dt and electromagnetic interference. The problems of high common mode currents and bearing and insulation damage, which are caused by high dv/dt, and the reliability of WBG devices are discussed.

Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor. Because of easy process control and energy saving, it mainly found in commercial and industrial facilities. Unfortunately, ASD is sensitive to power disturbances such as voltage sags. This paper analyzes the behavior of diodes rectifier current under normal condition and voltage sags of type A and C. Based on the experiment results, the behavior of diode currents are reverse bias during voltage sag and high inrush current appears after the voltage sag ends. Impact of type A voltage sag with various conditions are presented by voltage tolerance curve

—This paper presents an active phase current harmonic suppression method to smartly and adap-tively perform torque ripple minimization (TRM) under open phase fault conditions in a five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM). The five-phase machine is gaining increasing attention due to its promising fault-tolerant and wide speed operation capabilities. However, during fault-tolerant operation, the torque ripple is substantially increased with dangerous vibrations. Until now, most TRM has been primarily performed to maintain constant magneto-motive force (MMF) while only analyzing its fundamental harmonic. However, large torque variations are also caused by unexpectedly modulated high-order harmonic fluctuations which are challenging to predict. This fluctuation in current harmonics is highly destructive to reluctance machines due to its higher nonlin-earity. To address this critical challenge, a real-time active TRM technique has been proposed which will be smartly adaptive to identified harmonic fluctuations. To achieve this, the proposed TRM solution systematically consists of three major steps: (i) active harmonic identification, (ii) harmonic injection, and (iii) vector rotation of phases. To precisely identify fluctuating harmonics in a real-time, a high precision but compact correlation-based monitoring algorithm has been proposed. Detailed theoretical analysis has been carried out through Finite Element Analysis (FEA). The experimental tests are conducted to validate the proposed theory through a five-phase PMa-SynRM drive controlled by TI DSP (F28335).

In this article, a model predictive current controller for multilevel inverters driving electrical machines is proposed. The inverter switch positions are directly set by the controller, thus avoiding the use of a modulator. Admissible switching sequences are enumerated, and a state-space model of the drive is used to predict the drive's response to each sequence. The predicted short-term switching losses are evaluated and minimized. The concept of extrapolation and the use of bounds achieve an effective prediction horizon of up to 100 time steps despite the short switching horizon.

- by Muhd Hafizi Idris and +1
- •
- Electric Machinery, Electric motor drives, Voltage Sags and Interruptions, Electrical Machines

Rotating electrical machines are electromechanical energy converters with a fundamental impact on the production and conversion of energy. Novelty and advancement in the control and high-performance design of these machines are of interest in energy management. Soft computing methods are known as the essential tools that significantly improve the performance of rotating electrical machines in both aspects of control and design. From this perspective, a wide range of energy conversion systems such as generators, high-performance electric engines, and electric vehicles, are highly reliant on the advancement of soft computing techniques used in rotating electrical machines. This article presents the-state-of-the-art of soft computing techniques and their applications, which have greatly influenced the progression of this significant realm of energy. Through a novel taxonomy of systems and applications, the most critical advancements in the field are reviewed for providing an insight into the future of control and design of rotating electrical machines.

- by K.W. Chau and +1
- •
- Electrical Engineering, Control Systems Engineering, Artificial Intelligence, Machine Learning

- by Quinn Sullivan
- •
- Engineering, Electric Vehicles, Electric motor drives, Electrical Motors

Το άρθρο που ακολουθεί παρουσιάζει τη μετατροπή μαθηματικού μοντέλου τριφασικής ασύγχρονης μηχανής βραχυκυκλωμένου δρομέα σε σύστημα διαφορικών εξισώσεων κανονικής μορφής. Μερικά στοιχεία σχετικά με την αριθμητική επίλυση και το πρόγραμμα προσομοίωσης που βασίστηκε στο προαναφερθέν μοντέλο
παρουσιάζονται επίσης, καθώς και σχετικά διαγράμματα και σχόλια.

In an electric drive vehicle, the available voltage on
a DC-link is limited, and so the inverter output voltage and,
consequently, the line motor maximum speed are limited. The
fundamental voltage of the inverter output is increased
approximately 27% using a square wave switching pattern
instead of a sine wave switching pattern. However, this pattern
can only be used at high speeds, and at lower speeds a pulse width modulation pattern should be used. In order to achieve proper control, the switching pattern should be changed seamlessly. In the present paper, a new pulse width modulation (PWM) scheme for single-mode seamless control of Vernier motors is proposed.
In the proposed scheme, the reference voltage is modified to
change the switching pattern continuously so that the voltage
changes smoothly from a high-frequency pattern to a square
wave and voltage discontinuity does not occur. Experimental
results reveal that the inverter-switching pattern changes
smoothly from a sinusoidal pulse width modulation pattern to a
square wave pattern, and so seamless control from the constant torque region to the constant-power region, and vice versa, is achieved. Since the proposed scheme is a single-mode control, it is much simpler than current technologies, which are based on multi-mode controllers. Also the proposed method has a lower total harmonic disturbance (THD) as well as a lower harmonic distortion factor (HDF) compared to some existing methods.

- by ahmad ghaderi
- •
- Motor Control, Electric Vehicles, Electric motor drives, PWM Modulation Converters

As a result of dead-time, device on-state voltage drop, dc bus voltage measurement error, etc., volt-second errors degrade precise control of torque and flux linkage, particularly at low speeds. This is true for deadbeat-direct torque and flux control (DB-DTFC), which directly manipulates the volt-second vector sourced by inverters as well as for indirect field oriented control (IFOC) drives. This paper introduces a real-time sensing scheme to measure the motor terminal volt-second vectors for each switching period with negligible phase lag. Based on the volt-second sensing, a model reference adaptive system (MRAS)-based approach is developed to decouple the volt-second errors from inverter nonlinearity and dc bus voltage fluctuation and measurement error. By delivering an accurate volt-second vector for each switching period, torque and flux control accuracy, self-sensing performance and parameter estimation accuracy are significantly enhanced.

- by Yang Xu and +1
- •
- Motor Control, Electric motor drives, Induction Motor Drives, Sensorless Control

—In this paper, optimal phase advances under fault tolerant control (FTC) of a five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM) has been proposed under different fault conditions. Critical applications where the consistency and safety are the major concerns in automotive and aerospace industries require reliable control systems. The multi-phase motor is considered a promising candidate for these applications as it has redundant phases primarily for fault tolerant operation. However advanced fault tolerant control for a PMa-SynRM with maximization of reluctance torque is limitedly studied until now. In the conventional approach, to maintain constant magneto-motive force under fault conditions, phase currents of a motor need to increase significantly. However, this will easily saturate the PMa-SynRM resulting in significantly reduced reluctance torque. To overcome this issue, this paper proposes a novel phase current control method which maximizes reluctance torque with minimum phase current. Here, a phase current control with a novel phase advance has been proposed under various fault conditions. Extensive theoretical and experimental analysis has been carried out to verify the effectiveness of proposed idea with 5-hp dynamo system controlled by TI DSP F28335.

- by AKM Arafat
- •
- Power Electronics, Motor Control, Electric motor drives

Low-order odd current harmonics arise in practical multiphase drives due to machine and converter nonlinear behavior (e.g., deadtime and flux saturation). If the windings are distributed, some harmonics cause torque ripple, whereas others produce losses. The latter is aggravated by the small impedance in the no-torque subspaces. Current harmonics can be compensated without steady-state error by proportional–integral controllers in multiple synchronous frames (SFs); however, a heavy computational load is required. In three-phase systems, the computational burden of this multiple SF (MSF) scheme is often avoided by implementing instead resonant controllers (RCs) tuned at the harmonics that are multiples of six in an SF rotating with the fundamental frequency. A similar structure has been proposed for nonlinearities compensation in asymmetrical six-phase machines. This paper extends this multiple RC (MRC) strategy to symmetrical machines of any phase number. The optimum frequencies for the RCs and for the SF in each plane, so that the number of RCs is minimized, are established. Then, the computational load of the resulting generic MRC scheme is assessed and compared with that of the MSF structure. The conditions in which the former is particularly preferable over the latter are identified. Experimental results are provided.

- by Alejandro Gómez Yepes and +1
- •
- Electric motor drives, Digital Control, Electrical Motors, Electrical Machines
- by Duvan Parra
- •
- Electric motor drives
- by Tobias Geyer and +1
- •
- Power Electronics, Model Predictive Control, Model Predictive Control (MPC), Electric motor drives

Induction motors are used as industrial drive and for various applications in power plant due to their rugged, robust and simple construction as well as low cost. The speed control of SRIM is dexterous by slip power recovery scheme consisting of inverter control, chopper control, and rotor resistance control techniques. This paper presents the boost in the performance characteristics and energy saving of SRIM drive by inverter and buck-boost chopper based slip power recovery scheme (SPRS). The simulation model of a WRIM drive using inverter and based buck-boost chopper control has been executed in the Simulink platform. The simulation results using inverter and chopper control have been studied. The active power and reactive power have been taken as parameter for analyzing the energy saving by the drive. The simulation result has shown that inverter chopper control SPRS large amount of energy saving. I.

- by IJRASET Publication and +1
- •
- Electrical Engineering, Control Systems Engineering, Renewable Energy, Electric motor drives

This research is concerned with the implementation of a low-cost single-phase grid connected PV system including active power filtering functionality. The system is able to transfer surplus power to the grid, to compensate both reactive power and harmonics for nonlinear loads resulting in nearly unity power factor and nearly sinusoidal grid current. The system is controlled by a low cost dSPIC30F4011 microcontroller. Rectification and inversion mode operation is described. Software and hardware design of the system is given. The merit of the proposed system is simplicity especially for grid synchronization using zero crossing in conjunction with a sinusoidal look-up table. The process of reference current generation is fully described and demonstrated by experimental waveforms. Simulation and experimental results are compared in order to validate the proposed technique under various conditions such as low and high solar irradiation.

- by Zainal Alam Haron
- •
- Power Electronics, Electric motor drives, Power

Multiphase (MP) induction machines (IMs) provide important advantages over three-phase (3P) ones. Sensorless speed estimation allows to obtain high-performance control and monitoring without the inconveniences of speed sensors. In 3P IMs, the speed estimation methods based on rotor slot harmonics (RSHs), normally on the principal RSHs (PSHs), are well established. A difficulty of these techniques, in 3P IMs, is that RSHs are usually extremely small. Additionally, as previously assessed concerning 3P IMs, the number of rotor bars should be carefully selected; otherwise, the PSHs might not even arise in the stator current. However, no publications have addressed the magnitude of PSHs in MP IMs, in comparison to 3P ones, or selection criteria of MP IMs for speed-sensorless drives. In this paper, it is shown that in MP IMs larger (easier to detect) PSHs can be obtained, due to the low impedances in their additional stator planes, by appropriately selecting the number of bars and poles so that the PSHs are mapped into such planes. This finding is supported by newly developed stator equivalent circuits, which include the effects of rotor bars. Accordingly, criteria are presented to select MP IMs for speed-sensorless drives. Experimental and finite element results confirm the theory.

- by Alejandro Gómez Yepes and +3
- •
- Power Electronics, Electric motor drives, Multiphase systems, Electric Drives (Engineering)
- by Wahyu Utomo
- •
- Power Electronics, Electric motor drives, Power

This paper introduces an enhanced speed self-sensing method that tracks the stator flux linkage in induction machines at very low speeds. Volt-second sensing technology is used to mitigate the inverter nonlinearity, which is the major source of flux estimation error in the very-low-speed range. By integrating volt-second sensing in the Gopinath style closed-loop flux observer, the rotor speed information with more precision and lower noise is extracted from the estimated stator flux. Experimental results show that the proposed self-sensing method extends the low speed operating range, reduces the speed and torque ripple, and increases the disturbance rejection capability compared with the traditional self-sensing method based on the voltage integration method and the back-EMF tracking method.

- by Zainal Alam Haron
- •
- Power Electronics, Electric motor drives

This paper proposes a new sensorless speed control technique for induction motor (IM)driven electric vehicle (EV) using a model reference adaptive controller (MRAC) with a basic energy optimization technique known as golden section method. The proposed MRAC for the vector controlled IM drive utilizes instantaneous and steady state values of a fictitious resistance (R) in the reference and adaptive models respectively. The proposed scheme is immune to the variation in stator resistance (Rs). Moreover, the unique formation of the MRAC with the instantaneous and steady-state reactive power completely eliminates the requirement of any flux estimation in the process of speed estimation. Thus, the method is insensitive to integrator-related problems like drift and saturation enabling the estimation at or around zero speed quite accurately. The proposed drive's performance with the R-MRAC is validated for various speed ranges and patterns in Matlab/Simulink. Sensitivity of various motor parameters and stability studies are carried out using eigenvalues loci plots by first order eigenvalue sensitivity analysis.