<p>The VAWT project at Uppsala University has successfully managed to develop a vertical axis wind turbine (VAWT). The VAWT has many benefits compared to the Horizontal axis wind turbines (HAWT) which are the most common wind turbine design today. One of the many advantages with the VAWT is that it allows the generator to be located on the ground level. That reduces the required tower strength. The wind turbine is not self starting, i.e. the turbine needs a certain speed before the wind can force the turbine to revolve. The wind turbine is therefore in need of special start procedure. During the start, power electronics is used to operate the generator as a motor. Today Hall latches are located in the air gap of the generator which provides the signals that govern the power electronics. However, there is a demand to have a start that does not require Hall latches. Such controller would increase the reliability of the starter system. The design of the wind turbine could be even more simplified. Hence, the diploma work treats a programmed microcontroller to control the start-up without using any sensors at all. A hub motor was obtained for laboratory work, a driver and an inverter were constructed to drive the motor using a microcontroller. The finished start-up program has the ability to start the hub motor both sensorless and using Hall sensors. The microcontroller controls the motor by measuring the phase voltages of the motor. This information is used to decide which phases of the motor the electric current should go through. The current to the motor is limited using pulse width modulation strategy (PWM). Current limitation is necessary to protect the power electronics and limit the torque during the start. The result of start-ups using both Hall sensor and sensorless showed that the two start strategies are able to accelerate the rotor at the same rate. However, the start-ups using Hall sensors reached a higher top speed than the sensorless starts. However, the wind turbine is not in need of a higher speed than what the sensorless start was able to reach. Thus, the sensorless start is considered to be as good as the start using Hall sensors.</p>

The VAWT project at Uppsala University has successfully managed to develop a vertical axis wind turbine (VAWT). The VAWT has many benefits compared to the Horizontal axis wind turbines (HAWT) which are the most common wind turbine design today. One of the many advantages with the VAWT is that it allows the generator to be located on the ground level. That reduces the required tower strength. The wind turbine is not self starting, i.e. the turbine needs a certain speed before the wind can force the turbine to revolve. The wind turbine is therefore in need of special start procedure. During the start, power electronics is used to operate the generator as a motor. Today Hall latches are located in the air gap of the generator which provides the signals that govern the power electronics. However, there is a demand to have a start that does not require Hall latches. Such controller would increase the reliability of the starter system. The design of the wind turbine could be even more simplified. Hence, the diploma work treats a programmed microcontroller to control the start-up without using any sensors at all. A hub motor was obtained for laboratory work, a driver and an inverter were constructed to drive the motor using a microcontroller. The finished start-up program has the ability to start the hub motor both sensorless and using Hall sensors. The microcontroller controls the motor by measuring the phase voltages of the motor. This information is used to decide which phases of the motor the electric current should go through. The current to the motor is limited using pulse width modulation strategy (PWM). Current limitation is necessary to protect the power electronics and limit the torque during the start. The result of start-ups using both Hall sensor and sensorless showed that the two start strategies are able to accelerate the rotor at the same rate. However, the start-ups using Hall sensors reached a higher top speed than the sensorless starts. However, the wind turbine is not in need of a higher speed than what the sensorless start was able to reach. Thus, the sensorless start is considered to be as good as the start using Hall sensors.

In this dissertation harmonic current, harmonic torque originated at the load and harmonic torque originated at the motor, where modeled and treated via closed loop control. The dissertation propose a remedy for cancelling harmonic current by placing the proposed adaptive feedforward controller (AFC) in parallel with the FOC current control. Similarly, harmonic torque load was cancelled by proposing an AFC in parallel with the speed control loop. Harmonic torque originated in the motor mainly due to harmonic flux where cancelled through the estimation of harmonic flux, which was achieved by a novel Minimal Parameter Harmonic Flux Estimator (MPHFE). The latter is formulated such that the inductance, resistance, and stator current and its derivative are not necessary for the estimation of the harmonic eflux. This was achieved by forcing the harmonic current induced by the harmonic flux component to zero through the combined action of a Field-Oriented Controller (FOC) and a feed-forward controller. Subsequently, the harmonic flux can be obtained directly from the estimated harmonic back-EMF without the involvement of other motor parameters. Finally, the estimated flux is used in conjunction with a comprehensive analysis of the motor harmonic torque to determine the stator current compensation to eliminate the torque harmonic. A systematic approach to assign the parameter of the AFC controller were developed in this dissertation. Furthermore, multiple experiments were conducted to demonstrate the efficacy of the proposed control schemes harmonics.

The diploma work concerns on an issue of data collection of speed and electrical angle based on informations from Hall sensor with the necessary resolution for control of BLDC motor. Specifically, concenred on a section with low speed. Most of moors use Hall sensor for detecting speed and position of the rotor. At low speed section, becomes the situation when we can not determine the position of the rotor with (the) required (sufficient) resolution, this situation creates a „wince“ in the control (ripple torque). The task is to design and evaluate the possibilities of the algorithm for control and acquisition speed and rotor position with the required accuracy.

Saab AB Training &amp; Simulation is specialized on military training, including laserbased training. To continue being the world leader in this area, a new generationof laser simulators needs to be developed. To simplify the development of thishighly complex system, this master thesis have resulted in a MATLAB/Simulinkmodel which simulates the electro-opto/mechanical system representing theirlaser based simulation platform. The focus of this master thesis has been to simulateand control the laser beam deflection. To be more precise, the motors usedto rotate the Risley-prisms deflecting the laser beam is modelled. With a goodmodel of the motors, a control system is applied steering the wedges to a referencerotation angle. The reference rotation angle is difficult to calculate though,since the deflection following several rotary wedges is severely nonlinear. Thereare many ways to calculate the rotation angles, but in this master thesis it will bedone by solving optimization problems in MATLAB. / Saab AB Training &amp; Simulation är specialiserade på militär träning, bland annatbaserad på laser och för att fortsätta vara världsledande inom detta områdekrävs utveckling av en ny generation lasersimulatorer. För att underlätta utvecklingsarbetetav detta högst komplexa system, har i detta examensarbete en simulerbarmodell skapats i MATLAB/Simulink för att kunna simulera det elektroopto/mekaniska system som beskriver deras laserbaserade simulatorplattform.Fokus för detta examensarbete har varit att modellera avlänkningen. Mer ingåendeså modelleras de motorer som används för att rotera Risley-prisman så atten laserstråle uppnår önskad avlänkning. Med en bra modell av motorerna applicerasett reglersystem som styr de roterbara kilarna till referensposition. Referenspositionenär dock komplicerad att beräkna eftersom avlänkningen frånflera roterande kilar beter sig högst olinjärt. För att göra detta finns flera tillvägagångssätt,men i detta examensarbete kommer det att göras genom att lösaoptimeringsproblem i MATLAB.

This thesis is concerned with the speed control of a brushless DC (BLDC) fan motor by switching its coil currents. Because fans are the most common cooling devices for computers, the demand for a quit and efficient fan that is capable of automatically regulating its speed according to temperature grows with each passing day. A mixed linear and switching control scheme which consists of two loop of feedback compensation for a two-phase BLDC fan motor is presented. Roughly speaking, the linear outer loop is mainly for speed regulation, and the inner loop is to generate a switching control signal while doing plant compensation. This control structure is simple and effective, emphasizing on low power consumption, accurate velocity regulation and low switching noise. The performance and stability requirement can be easily met by tuning several positive coefficients in the controller. The experiment shows an average steady-state regulation error of 0.563% in the range of fan¡¦s speed from 1050 to 2231 r.p.m.

Saab has an analogue solution which is used to drive small motors in aircrafts. The motor is a brushless DC-motor and uses a resolver and hall sensors to control it. As sensorless control is something that has been expanding and attracting more interest over the last decade, Saab is considering the possibility of using a digital sensorless system depending on its performance on the control compared to their analogue system. There is little documentation of performance for a digital sensorless solution compared to an analogue solution. Therefore the question to be answered in this research is: How is the performance of the digital solution compared to the existing analogue solution? It was answered by finding a complete sensorless system on the market and then compare its performance to a digital system with sensors that resembles the analogue solution. Performance wise, InstaSPIN does not perform as well as EPOS2 which represent the sensorless system respective the system with sensors. InstaSPIN needs a startup sequence, can not run at the same low velocities, has a longer rise time, settling time and greater ripple. An examination of the software should be done before using the disadvantages that was found as a reason for not considering a sensorless system. Especially the startup sequence in the software should be examined as it is InstaSPINs greatest weakness compared to EPOS2. / Saab använder idag ett analogt system för att driva små motorer i deras flygfarkoster. Det analoga systemet använder en borstlös DC-motor och en resolver för styrning av motorn. Motorstyrning med system som är oberoende av givare är ett område som vuxit och fått ett ökat intresse det senaste decenniet. Saab överväger möjligheten att använda ett givarlöst digitalt system beroende på dess styrprestanda jämfört med deras analoga system. Eftersom det finns lite dokumentation om prestandan så är frågan som ska besvaras i denna rapport: Hur förhåller sig det givarlösa digitala systemet prestandamässigt jämfört med det existerande analoga systemet? Detta besvarades genom att leta upp ett komplett system på marknaden och sedan jämföra dess prestanda mot ett digitalt system som liknar det analoga systemet.  Prestandamässigt så fungerar InstaSPIN som representerar det givarlösa systemet inte lika effektivt som EPOS2 som representerar systemet som använder givare. Nackdelarna med InstaSPIN är att den behöver en startsekvens, inte kan köra på lika låga hastigheter, har längre stigtid, insvängningstid och större rippel. Man bör undersöka mjukvaran innan nackdelarna används som en anledning till att inte använda ett givarlöst system. Speciellt startsekvensen bör undersökas eftersom det är IntaSPINs största svaghet jämfört mot EPOS2.

The possibility to develop control systems for electromechanical actuators at Scania is studied, in particular the focus is on how to exchange the intelligent actuators used today with dumb ones. An intelligent actuator contains its own control electronics and computational power, bought as a unit from suppliers by Scania and controlled via the CAN bus. A dumb actuator contains no means of controlling itself and its I/O is the motor’s power pins. Intelligent actuators tend to have limited control performance, time delays and poor diagnose systems, along with durability issues. A dumb actuator could have the benefit of avoiding these disadvantages if the system is designed within the company. A literature study concerning the different types of electrical motors available and their control methods is performed, the most suitable for use in a heavy vehicle is deemed the brushless DC motor, BLDC. An intelligent throttle is chosen for a case study and has its control electronics stripped and replaced with new sensor- and control cards. The case study is used to investigate the possibilities and difficulties of this design process. A simulation model is developed for the electronics, motor and the attached mechanical system. With the aid of this model a controller architecture is designed, consisting of PI controllers with feed-forward and torque compensation for nonlinearities. The developed controller architecture is tested and in theory it can compete with the intelligent throttle’s performance. The model is also adapted to allow for code generation. The simulation model is used to study some common electrical faults that can effect the system and the possibilities for diagnosis and fault-remedial actions. The hardware prototype system shows that a current controller is necessary in the control architecture to achieve decent performance and the prototype is developed in such a way as to make future studies possible. The conclusion of the thesis is that Scania would be able to design control systems for dumb actuators, at least from a technical perspective. However more studies, from an economical point of view, will be necessary.

Cooling fans, widely used in desktop and laptop computers, have been designed toward the tendency of low noise and low consumption power. This thesis purposes a efficient low-noise double-loop control method to regulate the fan speed according to environmental temperature. The proposed controller consists of three parts. The first part is a command generator which generates a train of pulses with its frequency varying proportionally with temperature. The second part is a phase locked loop which intends to synchronize the command pulses with the pulses fed back from the Hall IC of the motor. The third part is an inner loop quantized control that switches the fan according to the error signal sent by the phase locked loop. This double-loop design of feedback achieves accurate fan speed regulation with the nice properties of low noise and high efficiency. The experimental results show an average regulation error of 0.4188% in the fan speed range of 306.6~1953 R.P.M which corresponds to the temperature range 10~70 Celsius.

The goal of this thesis was to evaluate sensors and motor speed control methods for BLDC/PMSM motors in Aerospace applications. The sensors and methods were evaluated by considering accuracy, robustness, cost, development gain and parameter sensitivity. The sensors and methods chosen to simulate were digital Hall sensors and sensorless control of BLDC motors. Using Matlab Simulink/Simscape some motor speed control methods and motor speed estimation methods were simulated using the Hall sensors and sensorless control as a basis. It was found that the sensorless control methods for BLDC motors couldn't estimate the speed accurately during dynamic loads and that the most robust and accurate solution based on the simulations was using the digital Hall sensors for both speed estimation and commutation and this was tested on a hardware setup.