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This thesis presents a systematic scheme to design the optimal efficiency operations and axial force control of a single-sided permanent-magnet axial-flux motor with center pole (SPAMC) through the detailed mathematical model and operational analysis. According to the rotating magnetic field theory combining with the recoil line characteristics of permanent magnet and the magnetic equivalent circuit, appropriate projection of the stator currents to achieve the optimal efficiency operations and axial force control can be realized. From these evaluations, a feasible operational guidance for SPAMC field oriented control (FOC) framework can be successfully developed. Finally, based on the proposed operational scheme, a DSP-based drive system has been successfully implemented, and the optimal efficiency operations and axial force control objectives can be achieved.

This thesis presents a systematic scheme to design the propulsive force and axial force control of a single-sided permanent-magnet axial-flux motor with aluminum stator core (SPAMA) through the detailed mathematical model and operational analysis. According to the rotating magnetic field theory combining with the recoil line characteristics of permanent magnet and the magnetic equivalent circuit, appropriate projection of the stator currents to achieve the propulsive force and axial force control can be realized. From these evaluations, a feasible operational guidance for SPAMA field oriented control (FOC) framework can be successfully developed. Finally, based on our system model and simulation results, the steady-stay characteristics of the machine can be observed.

The simplest form of induction motors, known as AC squirrel cage motor, is the universal workhorse of industrial and commercial premises. For many years it was restricted to constant speed applications while DC motors were preferred for high-performance variable speed and servo drives. With modern advances in semiconductor and digital signal processing technologies, it is now possible to operate induction motors in high-performance drives at a reasonable cost with Field Oriented Control methods. The latter have made induction motor drives equivalent to DC drives in terms of independent control of flux and torque; and superior to them in terms of dynamic performance. In developing Field Oriented Control for induction motors engineers are faced with two major challenges: (1) the estimation of rotor data to compute for the slip gain, and (2) the compensation of changes in drive operating conditions and parameters in order to maintain the drive performance high at all time. This thesis addresses these issues by introducing two independent control systems. The first system is designed to estimate online the value of the slip gain in the entire torque-speed plane in order to maintain decoupled control of torque and flux despite the so-called detuning effects. It is based on evaluating the operating condition of the drive in terms frequency and load torque, and selecting the appropriate estimation method accordingly. A fuzzy controller is used to generate the distribution factor for the methods. The second system is a fuzzy self-tuning speed controller, with reduced sensitivity to motor parameters and operating condition changes. It has the ability to adjust its gains in real time according to the current trend of the drive system. It is designed to maintain tight control of speed and torque for high-performance applications. The performances of the two controllers are validated through a series of simulation and experimental tests using a 2HP 3-phase induction motor with an ADMC21992 160-MHz DSP microprocessor. / Power Engineering and Power Electronics

This report describes the work of developing a rapid prototyping system for Permanent Magnet Synchronous Motors using LabView FPGA at ABB Corporate Research in Västerås. The aim of the rapid prototyping system is to serve as an additional tool to simulation when evaluating new control algorithms for mechatronic applications. Using LabView FPGA, Field Oriented Control is implemented for a single axis and a multi axis system on the sbRIO 9632 development board from National Instruments. The aim is to develop a controller for multiple axes while optimizing the use of system resources. The report presents the work of testing and evaluating the implementation of the single axis system. The system will be tested in a laboratory test bench to verify its performance. The laboratory results are compared and verified against MATLAB/Simulink simulations of the system. Using the results from the single axis tests as a benchmark the multi axis system is verified and evaluated. The implemented systems proved to provide good regulation of the motor currents for both the single axis and the multi axis system.

The researchers at the Department of Electricity at Uppsala University has recently entered the field of electric motor design, however no real knowledge of motor control of salient pole permanent magnet motors exists in the department. This thesis will present a general description of the control method of motors that exist today, this has been done by reviewing existing literature. The literature review has shown that there are at least three control methods with a significant different in their control approach, Scalar-, Field Oriented- and Direct Torque- Control. The two last methods were chosen by the author as the most useful and was implemented and simulated together with the newly developed motor in MATLAB Simulink to evaluate their performance. The simulation results show that there is no difference in performance of the two methods, but they show a difference in efficiency. The results show that it's worth to develop both methods further, mainly for reducing the torque and current ripple. This result was not expected according to literature, which suggests that the Field Oriented Control has a lower torque ripple. This could be caused by the choice of hysteresis control for inverter switching, instead of more sophisticated methods with a proportional integral derivative controller (PID) together with Sinusoidal Pulse Width Modulation (SPWM) or Space Vector Modulation (SVM).

The automobile industry is moving fast towards Electric Vehicles (EV); however this paradigm shift is currently making its smooth transition through the phase of Hybrid Electric Vehicles. There is an ever-growing need for integration of hybrid energy sources especially for vehicular applications. Different energy sources such as batteries, ultra-capacitors, fuel cells etc. are available. Usage of these varied energy sources alone or together in different combinations in automobiles requires advanced power electronic circuits and control methodologies. An exhaustive literature survey has been carried out to study the power electronic converter, switching modulation strategy to be employed and the particular machine to be used in an EV. Adequate amount of effort has been put into designing the vehicle specifications. Owing to stronger demand for higher performance and torque response in an EV, the Permanent Magnet Synchronous Machine has been favored over the traditional Induction Machine. The aim of this thesis is to demonstrate the use of a multi level inverter fed Brush Less Direct Current (BLDC) motor in a field oriented control fashion in an EV and make it follow a given drive cycle. The switching operation and control of a multi level inverter for specific power level and desired performance characteristics is investigated. The EV has been designed from scratch taking into consideration the various factors such as mass, coefficients of aerodynamic drag and air friction, tire radius etc. The design parameters are meant to meet the requirements of a commercial car. The various advantages of a multi level inverter fed PMSM have been demonstrated and an exhaustive performance evaluation has been done. The investigation is done by testing the designed system on a standard drive cycle, New York urban driving cycle. This highly transient driving cycle is particularly used because it provides rapidly changing acceleration and deceleration curves. Furthermore, the evaluation of the system under fault conditions is also done. It is demonstrated that the system is stable and has a ride-through capability under different fault conditions. The simulations have been carried out in MATLAB and Simulink, while some preliminary studies involving switching losses of the converter were done in PSIM.

Induction motors and Variable Frequency Drives (VFDs) are widely used in industry to drive machinery trains. However, some mechanical trains driven by VFD-motor systems have encountered torsional vibration problems. This vibration can induce large stresses on shafts and couplings, and reduce the lifetime of these mechanical parts. Long before the designed lifetime, the mechanical train may encounter failure. This thesis focuses on VFDs with voltage source rectifiers for squirrel-cage induction motors of open-loop Volts/Hertz and closed-loop Field Oriented Control (FOC). First, the torsional vibration problems induced by VFDs are introduced. Then, the mathematical model for a squirrel-cage induction motor is given. Two common control methods used in VFD are discussed - open-loop Volts/Hertz and closed-loop FOC. SimPowerSystems and SimMechanics are used as the modeling software for electrical systems and mechanical systems respectively. Based on the models and software, two interface methods are provided for modeling the coupled system. A simple system is tested to verify the interface methods. The study of open-loop Volts/Hertz control method is performed. The closed-form of electromagnetic torque sideband frequency due to Pulse Width Modulation is given. A torsional resonance case is illustrated. The effects of non-ideal power switches are studied, which shows little in uence on the system response but which uses little energy consumption. A study of a non-ideal DC bus indicates that a DC bus voltage ripple can also induce a big torsional vibration. Next, the study of the closed-loop FOC control method is presented. Simulation for a complete VFD machinery train is performed. With the recti er and DC bus dynamic braking, the system shows a better performance than the ideal-DC bus case. Lastly, a parametric study of the FOC controller is performed. The effects of primary parameters are discussed. The results indicate that some control parameters (i.e. speed ramps, proportional gain in speed PI controller) are also responsible for the mechanical torsional vibration.

In vector control of induction motors it is essential to know the parameters of the motor. Known approaches to this problem have some drawbacks. This thesis work is planned to develop solutions to the existing problems. The proposed solutions will be implemented and tested.

The objective of this thesis is to present the algorithm of achieving speed and lift force controls of transverse flux linear switched-reluctance machine (LSRM) simultaneously. A high-speed digital signal processor based (DSP-based) switching controller will be implemented, and the desired speed control objective is realized by using a fuzzy control scheme. On the other hand, by using an indirect field-oriented control scheme, the LSRM reluctance forces, which are magnetically decoupled and position dependent, can be projected onto sets of stationary axes that are aligned with the motor fixed secondary poles. Hence by controlling flux on the specific stationary axis, the machine lift force can be properly controlled. Finally, adequate duty cycle distribution will be discussed and examined to asynchronously supply the required speed and lift force control objectives simultaneously.