This work proposes new standstill and online vector control methods for PMSM parameter measurements without mechanical locking of the shaft. In laboratories without proper test facilities, rotor clamping may not be feasible during parameter measurements. High frequency current commands are used to ensure that due to its inertia, the rotor will remain in the aligned position during measurement. The experimental results with the proposed standstill methods are compared with Finite Element analysis and experimental results from other two established methods: DC current method and sinusoidal AC method. The results show that standstill vector control is superior since it has lowest mean percent deviation as well as standard deviation.

This paper develops an analytical thermal model for an induction machine with a stator-inter turn fault. With a motor design software, a lumped parameter thermal network (LPTN) model is derived for a healthy machine. The LPTN model is modified to incorporate the fault conditions. Fault current and copper losses caused by the stator inter-turn fault are calculated using the mathematical model. With this approach, the temperature of the machine in the stator back iron, end plate, and housing are predicted with simulation studies. The results are validated with experimental studies. The developed model has an application for power-hardware-in-loop (PHIL) real-time emulation of machine fault behavior.

This work investigates the application of an Iron-Nitride (FeN) Permanent Magnet (PM) material to variable flux motors (VFMs). Two existing VFMs are used as references, a rareearth-free inverted saliency VFM and a series hybrid VFM. Initially, the inverted saliency VFM performance is evaluated for equal usage of PM material. Then, the PMs are resized for achieving similar electromagnetic performance to the reference VFM. It is noted that although the new PM has 25% higher residual flux density than AlNiCo9 PM, it requires high current for remagnetization. However, adopting the FeN magnet to the inverted saliency machine can allow reducing the PM usage by 42% and hence reduced rotor weight would be expected. By replacing the rare-earth magnet of the series hybrid VFM with FeN, comparable constant torque performance is attained with the advantage of avoiding rare-earth magnet demagnetization risks. This shows that for the investigated torque density levels, the FeN magnet has a high potential for designing existing/upcoming regular and hybrid magnet VFMs.

This paper presents a novel approach to introducing non-uniform static eccentricity to a Doubly Fed Induction Machine (DFIM) without the need for machine disassembly, enabling flexible and continuous adjustment of the eccentricity fault. This method could be applied to various types of radial flux machines, enhancing experimental convenience and safety compared to traditional techniques. Subsequently, an experiment was conducted to verify the simulation results of the mechanism's performance, further validating its efficacy.

Rising recognition of the financial risks posed by sudden failures in electric machines, particularly those operating under critical conditions, underscores the need for advanced fault diagnosis. Among the various mechanical faults, eccentricity faults, especially inclined or axially non-uniform static eccentricity, remain less explored in the literature despite their practical relevance. This paper develops a mathematical model based on the modified winding function method (MWFM) for a wound rotor induction motor to address this gap. Furthermore, it explores the application of power hardware-in-the-loop (PHIL) based emulation techniques to accelerate the testing of these eccentricity faults. Experimental data validate the mathematical model and underscore the efficacy of the PHIL-based machine emulator in emulating different degrees of eccentricity fault conditions. Additionally, the study contrasts the impacts of axially uniform and non-uniform static eccentricity, providing valuable insights into the detection of these faults.

For accurate prediction of iron losses in steel laminations, manufacturing effects and actual flux distributions has to be considered in the measurement process. This work aims at proposing a systematic iron loss measurement segregation approach between a tester and an assembled stator core. The tested stator core is exposed to different magnetization levels and frequencies along with different pole configurations produced by the magnetizer to assess the proposed approach. The effects of stator assembly, as well as the rotating nature of the excitation flux, are considered. It is shown that the employment of manufacturer steel data at high flux densities results in a considerable underestimation of the assembled stator core losses. Therefore, a comparison has been conducted between measured specific iron loss data of the stator core and the standard Epstein frame data for the particular M36G29 steel lamination comprising the tested stator.

Wind turbines play an increasingly important role in renewable power generation. To ensure the efficient production and financial viability of wind power, it is crucial to maintain wind turbines’ reliability and availability (uptime) through advanced real-time condition monitoring technologies. Given their plurality and evolution, this article provides an updated comprehensive review of the state-of-the-art condition monitoring technologies used for fault diagnosis and lifetime prognosis in wind turbines. Specifically, this article presents the major fault and failure modes observed in wind turbines along with their root causes, and thoroughly reviews the techniques and strategies available for wind turbine condition monitoring from signal-based to model-based perspectives. In total, more than 390 references, mostly selected from recent journal articles, theses, and reports in the open literature, are compiled to assess as exhaustively as possible the past, current, and future research and development trends in this substantial and active investigation area.

The power-hardware-in-the-loop (PHIL)-based machine emulator systems use controlled power converters to mimic machine behavior. This testing method allows testing of the drive inverter and drive controller prior to the manufacture of an electric motor prototype. In this paper, a PHIL-based machine emulation system is used to mimic the behavior of a three phase induction machine (IM) which is connected to the grid. However, it is essential for the emulator inverter to have a dead time between the upper and lower switches. This dead time in the emulator inverter leads to lower order harmonics which deteriorate the motor emulation accuracy. Thus, it is important to investigate and analyze the effect of dead time in emulation. A detailed analysis of the dead time effect on motor emulation is presented. Experimental results are obtained from the emulator system and from a squirrel cage induction motor to validate the proposed emulator with various dead times.

This paper presents the current controller-based parameter measurement of a variable flux permanent magnet synchronous machine (VFM) for different magnetization states (MS). A series of pulse currents are supplied to the VFM in a closed-loop system. The machine voltage and current response are measured and are processed in real-time to calculate the flux linkage, inductance and resistance. Thus, automated machine parameters are generated in real-time by the real-time processor. Since the same closed-loop system is used to change the machine MS to the desired level, the machine parameters for different MS can be automatically calculated. Experimental validation is performed on a 5 hp VFM. The experimental results are compared with the finite-element analysis results and show a good correlation.

The design, simulation and testing of an impulse magnetizer and the in-situ post-assembly magnetization of a permanent magnet (PM) rotor manufactured by a cold spray additive manufacturing (AM) using the prototyped magnetizer is presented in this paper. A software based finite element simulation is done to obtain the level of magnetization current required. An impulse magnetizer is built for this specification. A 4-pole rotor with cold-sprayed rectangular magnets is magnetized in this work after assembling it in the stator. Various stator terminal connection configurations are analyzed. The machine is magnetized and the back-EMF waveform and the rotor magnetization profile is obtained.

This paper focuses on the sizing approximation and parameter estimation of a Linear Generator (LG) to be driven by a direct drive free-piston engine. The modeled and designed LG is of tubular topology comprising of an outer stator with a 3-phase winding configuration and inner slider having layers of axially magnetized PMs and spacers. Two design approaches have been used for the linear generator sizing approximations based on initial requirements. Equations for determining geometrical parameters have been derived. Finite Element Analysis (FEA) simulation and a MATLAB model were developed highlighting the inputs and outputs of the designed LG.

The induction generator, in particular the self-excited induction generator (SEIG) is adopted in remote areas and can work in isolated systems. In such isolated systems, there are nonlinear loads, which may inject harmonics into the SEIG systems. However, it is difficult to test the nonlinear load condition of a real SEIG system in the laboratory. In this paper, a power electronic converter-based SEIG emulator is developed to investigate the SEIG feeding nonlinear loads. The mathematical model of induction generator (IG) and emulator converter are established and verified from the SEIG emulator. The comparison of the emulation results and actual experimental results demonstrate the validity of the proposed solution.

The induction machine (IM) is commonly adopted in industry, which plays an important role in energy conversion between mechanical power and electrical power. Asymmetrical faults caused by internal failures commonly occur in IMs. Such faults not only reduce the working efficiency and cause excessive heating, but also cause potential hazards preventing continuous operation and safety problems. In this paper, a power electronic converter-based IM power hardware-in-the-loop (PHIL) emulator is developed to emulate an IM with internal faults. The IM mathematical model with an inter-turn short circuit of the stator winding is established and verified in the built IM emulator. A comparison of the emulator results with simulation results and actual experiments demonstrates the validity of the proposed solution.

Designing and testing of electric vehicles (EVs) is a time-consuming process because of the iterations involved in the electric machines (EMs) and their power electronics (PEs) designs. Most of the time, both designs are done sequentially by using the output of the machine design step for proper sizing of its PEs. This paper proposes a novel fast and systematic method that sets a common ground for electric machine design and drive engineers allowing them to work in parallel and speed up the EV drivetrain development process. The proposed method is based on estimating key parameters such as magnet flux linkage, the d-q axis inductances, motor terminal voltages, and currents based on the drive requirement in terms of torque-speed envelope and battery terminal voltage. A case study based on an industrial project has been performed to show the feasibility of the proposed approach on a 7.12 kW surface and inset permanent magnet synchronous machine (SPMSM and IPMSM) drivetrains. New equations have been developed for getting IPMSM parameters from a feasible SPMSM design. Design steps and performance characteristics using simulation and finite element analysis (FEA) software are discussed. The effectiveness of the proposed design approach is also validated using MATLAB Simulink.

The permanent magnet (PM) traction motor is one of the feasible solutions to the energy crisis and environmental pollution. Due to the high demands in power and torque density with overall high efficiency, the permanent magnet synchronous machine (PMSM) is mainly considered. Usage of soft magnetic composites (SMC) material in the machine parts helps to build a complex 3D structure and reduces the manufacturing cost. This paper presents the electromagnetic performance comparison analysis of a 7.12 kW radial flux PMSM with laminated steel and SMC stator core. Two different designs of 24/20 slot-pole and 12/8 slot-pole configuration using conventional surface permanent magnet rotor design are simulated using a 3D FEA software package. The comparison is mainly focused on the torque density, copper loss, core loss, and active weight of the machine. In addition, the ring-type Halbach-array PM rotor fabricated using cold spray additive manufacturing for 12/8 slot-pole is analyzed and optimized with the SMC stator core for high-speed electric vehicle application. The THD in phase back EMF and torque ripple is reduced by modifying the SMC stator tooth shape. Also, a scaled-down laboratory design of ring-type Halbach-array PM rotor with 12/10 slot-pole is simulated using FEA with different lamination thickness of rotor core.

In this paper a PMSM model is proposed as a flexible and accurate tool for machine designers to conveniently evaluate the performances of a new PMSM design or a specific modification on an existing design base on the stator and rotor geometries. A step-by-step procedure is discussed, and informed assumptions are proposed to keep the model adaptable to different geometries. A reference IPM motor is used as an example of an application of the model. The model results are compared with FEA-based simulation and experimental validation.

This paper uses an adaptive nonlinear filter to estimate the variable flux permanent magnet synchronous machine (VF-PMSM) back EMF. The VF-PMSM is demagnetized at high speed to limit the machine terminal voltage and magnetized at low speed to maintain the torque by injecting a short current pulse. In this paper, harmonics present in the machine back EMF due to different magnetization/demagnetization current pulse widths and magnetization methods are analyzed. In addition, the effect on the harmonic spectrum present in VF-PMSM back EMF when demagnetized with pulse current and continuous current is discussed. Usually, a d-axis current required to magnetize the VF-PMSM is larger than the machine rated current. Thus, the inverter rating corresponding to the machine rating cannot achieve 100% magnetization. The minimum pulse amplitude and width to magnetize the VF-PMSM is experimentally determined to calculate the inverter oversize considering the available DC bus.

The paper presents for the first time the use of a low cost Hall effect position sensor for a synchronous reluctance machine (SynRM). The use of vector control for a SynRM requires information of the rotor position. Already the SynRM is independent of the use of permanent magnets (PMs) which results in reduced cost of the SynRM. Hence the use of a low cost position sensor contributes to an additional cost reduction of the electric drive for traction applications. The paper also presents a comparison between the low cost position sensor with the digital hall effect position sensor used in the electric power steering (EPS) machines. The different dynamics of the SynRM were demonstrated through the use of the low cost position sensor. The low cost position sensor had a relatively simpler algorithm for position information and better position resolution. Through the use of the low cost position sensor the machine produced low torque ripples of less than 9% with a total current harmonic distortion (THD) of less than 2%. The proposed position sensor registered an error less than 1 mechanical degree when compared with a 12-bit industrial encoder.

In this paper, design aspects of a 6-pole synchronous reluctance traction motor are presented for improving the machine performance in electrified powertrain applications. An increase in the number of poles at the same current rating amplifies the output torque and reduces the torque pulsations. Moreover, in this machine, anisotropic structure of the rotor eliminates use of cage, windings, and magnets results in a lower cost. Combination of the aforementioned qualifies this machine as an important candidate for the traction motors in the near future. The rigid structure of rotor enables the machine to operate at high speed that leads to compactness and higher torque density. To achieve a proper design, the machine needs to meet a desired torque envelope in different modes of operation i.e., start-up, acceleration, and cruising that highlights the cross sectional effects of the magnetic and mechanical performances. In this work, the magnetic and mechanical performance analyses of a 6-pole machine with respect to the pole numbers, rotor multi-layer structure, rotor mechanical robustness, desired torque envelope, and the maximum operating speed are discussed and compared with a well-known 4-pole geometry in order to address the proposed machine perforce improvements.

This paper presents a novel DC-link voltage balancing algorithm for a 3-level DC/AC traction inverter drive. In this topology, two DC-link capacitor voltages and three-phase line currents are measured, to generate the control pulses for the traction inverter, based on space-vector pulse width modulation (SV-PWM) scheme. Depending on the states of the two DC-link capacitors, redundant voltage vector sequences are used, to keep the capacitor voltages within a particular tolerance level. Phase current directions are also taken into account, because below a certain power factor level, it affects the capacitor voltage balancing capability. Simulation and experimental results are presented in this paper for a 6.0 kW interior permanent magnet synchronous machine (IPMSM) used for the electric vehicle (EV) traction applications. Both the simulation and experimental results show required performance of the proposed system.

A modified DC-link voltage balancing scheme for a three-level neutral point clamped inverter (NPC) with an interior permanent magnet machine (IPMSM) is presented. It uses two DC-link voltage sensors to take care of the voltage differences, and keep it to a required tolerance level. Switching control strategy is developed using a space-vector pulse width modulation (SV-PWM) scheme. Number of switching per switching cycle is optimised to five and changes in control strategy, depending on two capacitor voltage differences are only allowed to take place at starting of each switching cycle. It helps to reduce the switching losses. Details simulation studies are carried out in Matlab/ Simulink platform and an experimental setup is developed using dspace® based real time emulator. Simulation and experimental results show effectiveness of the proposed system.

This paper presents a comparative study on the effects of the number of poles on the synchronous reluctance machine's magnetic and mechanical performances for automotive applications. In automotive applications the design limitations i.e., proper size, maximum speed, torque envelope, and converter rating make the design sensitive to magnetic and geometric parameters such as the number of poles. Low torque ripple requirement for traction motors leads to the number of poles higher than two. From a rotor geometry point of view the number of poles higher than six would not be feasible in today's compact traction motors. Two different motor alternatives using 4 and 6 poles have been designed using a sizing methodology. In this work, machines equipped with transversally laminated anisotropic rotors. Magnetic and mechanical performances of the machines are analyzed and compared with regards to the design requirements. Finally, the proper design alternative will be addressed for automotive applications.

Economy of Central African countries is growing very fast and the energy demand is increasing daily. As a result, the insufficient of electrical power generation is one of the major problems that slow the development. This paper is mostly focused on a technical and economical feasibility study of building integrated photovoltaic system (BIPVS) supposed to be compatible with the local consumption habit. To achieve this goal, a model of building with 263 kWh daily consumption is studied. A high efficiency dc-ac converter is modeled and controlled to interface the integrated photovoltaic system with the grid and building. A sliding mode algorithm is used to control a dc-dc converter for extracting the maximum available power from photovoltaic system. For emergencies, a battery pack is designed to supply sensitive equipment and lighting. The studied system is validated using the professional PV*SOL software and "Matlab/ Simpower system". The results are promising and could be an efficient solution to the mentioned problems.

This paper deals on control strategy and analyzing power flow between home integrated photovoltaic system (PVS), plug-in hybrid electric vehicle (PHEV) and distribution network The neutral point clamp (NPC) multilevel inverter is the main element that allows interfacing between the different energy sources and receptors. The combination of synchronous reference frames (SRF) and indirect control algorithms applied to NPC, has allowed the system working in On and Off-grid condition for providing a continuous and uninterruptible power supply, for minimizing losses and managing effectively the power flow. The integrated PVS is supposed to satisfy a power load demand in the normal condition of solar irradiation. A PHEV is charging from PVS or grid and could supply power in case of off-grid emergency situation. An onboard bidirectional charger is modeled and controlled by sliding mode algorithm in order to ensure a secure charging and discharging of PHEV batteries. The system is tested for power factor correction and voltage regulation along with harmonic elimination. The performance of the system is validated using MATLAB software with its Simulink and power system blockset toolboxes.

The recent development of electric vehicles and electronic equipment has resulted in a demand for portable power supply systems with high power density and life expectancy. High Temperature (HT) Proton Exchange Membrane (PEM) fuel cells have emerged as a possible solution to this requirement. Recent advances in the materials allow the cells to operate at higher temperatures resulting in a number of advantages. These systems still suffer from degradation mechanisms that can degrade performance and decrease the life expectancy. In order to diagnose the fuel cell performance and degradation mechanisms, impedance analysis can be performed. This paper presents a design for the power electronic hardware that can perform these analyses online for single cell applications, where the output voltage is very low. Special consideration must be given to the hardware selection and small signal injection capability. The Nyquist plots and small amplitude current step voltage response of the HTPEM fuel cell is presented along with those captured after catalyst degradation has occurred. It is shown how the online system can capture these changes by using equivalent circuits.

This paper presents a modified DC bus voltage balancing algorithm for a neutral-point clamped (NPC) three-level inverter based motor drives for permanent magnet synchronous machines (PMSM) used in electric vehicle applications. The topology used for DC bus voltage balancing is based on nearest three vectors (N3V) with a space vector pulse width modulation scheme (SV-PWM). In this scheme, the voltage space vectors are rearranged based on the four redundant small voltage vectors, to keep the two DC link capacitor voltages in their specific tolerance bands, even during fast transient conditions of the machine. This topology provides high stability and lower switching loss compared to the conventional N3V scheme. The performance of the proposed scheme is verified by simulation and hardware experimental tests.

This paper investigates the performance of a two level and a three level inverter drives for a permanent magnet synchronous machine (PMSM) under different switching frequencies. The experiments were conducted via a real time based system called Opal-RT. The inverters were operated at 1 kHz and 5 kHz switching frequencies. The torque was varied between 2 N.m and 4 N.m at a constant speed of 800 rpm. However the torque ripples and the copper losses between the two inverter drives were similar and the copper losses were independant of the swicthing frequency. At 5 kHz inverter switching frequency the two level inverter performed better at 4 N.m with a total current harmonic distortion of 2.55% and a torque ripple of 10%. However overall the three level inverter had low voltage and current harmonic distortion which translates to lower iron losses. Swicthing at 5 kHz frequency showed to have lower overall harmonic distortion than at 1 kHz for both inverters. The greater the capcitor voltage error the more the torque ripples even though the machine registered lower current total harmonic distortion for the three level inverter.

In this paper the behavior of core loss coefficients is studied using a new method of core loss separation. This method eliminates the assumption of uniform magnetic field distribution in a material especially at high frequencies. With this separation method, the hysteresis and eddy current coefficients are calculated using the original Steinmetz equation and its derivative. The calculated loss from the coefficients of the two formulas is then compared to the loss from the separation. Results and conclusions are also presented.

This paper studies different magnetization process of low cost permanent magnets used for permanent magnet synchronous machines (PMSM). Due to the limited resource availability of the rare earth materials, it is required to have an alternate solution for magnets used for permanent magnet machines. The type of magnet should be readily available and low cost. This paper gives a thorough review of the existing low cost magnets, those are generally being use in the PMSM machine and their control using power electronics converters.

This paper presents a modified stator flux estimation based direct torque control drive of a permanent magnet synchronous machine (PMSM) used in an hybrid electrical vehicle. It provides satisfactory transient and steady state performance of machine torque and speed over a wide speed variation. This utilizes a modified stator flux estimation scheme where a phase and magnitude compensator has been introduced at the output of low pass filter to compensate the error; this error keeps on changing with machine operating frequency. Detail simulation studies are carried out to verify the results in Matlab simulink platform.

Concerns about air pollution, environmental degradation, and petroleum consumption have prompted policy makers in many countries to seek advanced transportation alternatives. In response to such societal needs, automobile manufacturers have develope vehicles which either replace the internal combustion engine with an electric motor or which provide a hybrid configuration with a combination of an IC engine (ICE) and an electric motor. In some concepts, fuel cells replace the IC engine in a hybrid vehicle configuration. Several of these technologies have been brought to market by auto manufacturers, with initial product offerings. In other cases, advanced concept cars are being developed to further these technologies. In response to these same concerns, research and development projects are underway to make the ICE vehicles more efficient. These projects have involved both improvements in engine/drive train efficiency as well as more efficient heating-cooling systems. This paper provides an overview of the transportation sector usage patterns, energy consumption, and emissions, and discusses the societal issues which impact decisions on transportation issues. The article then provides an overview of the electrotechnological advances which are being developed to address transportation energy use and emissions issues, and discusses the potential for emissions reduction through the successful deployment of these and competing technologies. The article concludes that reduction in transportation sector carbon emissions are achievable.