Hydropower is an important part of renewable power production in Sweden. The voltage stability of the already existing hydropower needs to be improved. One way to do this is by improving the control system that damp terminal voltage oscillations. If the oscillations in the power system are not damped it could lead to lower power outputs or in the worst case a blackout. This thesis focuses on the automatic voltage regulator (AVR) system with a proportional, integral, derivative (PID) controller. The PID controller’s parameters are optimized to dampen the terminal voltage instability in a generator. The aim is to develop a machine learning model that predicts the optimal gain parameters for a PID controller. The model is using the tuned gains from the Ziegler-Nichols (Z-N) method and the amplifier gain as inputs and gives the optimal gains as output. A linearized model of an AVR system, based on transfer functions was developed in a MATLAB script. This model was used to simulate the behaviours of an AVR system when a change in load occurs. The Z-N method and the genetic algorithm (GA) with different settings and fitness functions were used to tune a PID controller. The best performing method is GA with the fitness function developed by Zwe-Lee Gaing (ZL).  The best performing settings are: roulette selection, adapt feasible mutation, and arithmetic crossover. The GA (ZL) was used in the development of a machine learning model. Two different models were developed and tested: the support vector regression (SVR) and the gaussian process regression (GPR). The data that was used to train the models were generated by changing the transfer functions’ time constants 4096 times. At each step, the Z-N, and the GA (ZL) were run. The GPR model is shown to be the superior model with a lower root mean square error (RMSE) and a higher ratio of variation (R^2). The RMSE for GPR is 0.1091, 0.0815, 0.0717 and the R^2 is 87 %, 59 %, and 86%. The result shows that the developed model has capabilities to optimize the PID controller gains of any AVR-system without knowing the characteristics of the components.

Master’s thesis deals with a design and a realization of multifunction board computer for motorcycles. The goal of the device is measuring speed, rotation speed of engine, temperature of ambient, temperature of engine, temperature in intake including signalization of overvoltage and hightemperature. The device is completed by above standard function such as measuring titl of motorcycle, climbing of route, route recording and data transmission to the computer. The thesis includes a complete solution of hardware and software part of the device.

The theme of this thesis is the design and verification of the auxiliary winding to supply the voltage regulator of the synchronous generator. The synchronous generator for which the auxiliary winding proposed is three-phase, low voltage with double layer random wound stator winding. The generator excitation is brushless with auxiliary rotating exciter. The auxiliary winding is designed for placement in the stator teeth, along with the main winding. The sizing of the auxiliary winding is derived from the power requirements the voltage regulator. Draft winding is validated analytical calculation and finite element method (FEM). The auxiliary winding has been implemented in the production of the generator. The Features of the auxiliary winding have been verified by measuring the by electrical testing room and the test results are evaluated.

The presence of turnip crinkle virus (TCV) in Arabidopsis thaliana plants has previously been shown to suppress the ability of these plants to produce a hypersensitive response (HR) upon inoculation with pathogens that would normally elicit this defense response. The ecotype Colombia-0 was examined using wildtype TCV and non-pathogenic strains of Pseudomonas syringae pv. glycinea Race 4 containing virulence genes avrRpt2, avrRpm1 and avrRps4. Transgenic lines of A. thaliana that express the TCV proteins p8, p9 or CP were also examined in an attempt to determine if these proteins play a role in suppression of the HR. Crosses of these transgenic lines were made in order to determine if binary combinations of these proteins were sufficient for HR suppression. In addition, assays were completed to determine if the inhibition of the HR correlated with suppression of resistance to the virulent Pseudomonas syringae pv. maculicola ES4236 avrRpt2 growth in the plant. Finally, PR-1 protein expression was inspected by visual and quantitative GUS reporter gene assays to determine if TCV also played a role in inhibition of the plants ability to develop systemic acquired resistance (SAR).

This Master’s thesis deals with design and construction of a wireless security and surveillance system in ZigBee wireless networks (IEEE802.15.4). The design consists of creating a star network topology with intended monitoring of home area via end device boards paired with coordinator board, which provides basic networking functionality. End device is used to send data from a temperature sensor DS1631 and magnetic reed switches to coordinator. ZigBee module ZDM-A1281-A2 made by MeshNetics company embedded on each board contains a micro controller ATMega1281 and a transceiver AT86RF230 working in a 2,4GHz frequency band. System is able to notice of any door or window move actions and too high temperature. The non-fully functional ZigBee stack, which is called an Open MAC software, based on MAC (Media Access Control ) layer and PHY (Physical) layer from MeshNetics, has been used to develop the user software. Open MAC consists of three application samples in C code. One of them was modified by the user for an application of communication between the module and sensors. The same design with module RC2204AT made by Radiocrafts company was tested as well, but it couldn’t be executed. All developed boards have been constructed and tested via Terminal PC program.

The thesis is focused on the development of a radioamateur short-wave transceiver. The basic functions, features and parameters are described in the introduction. The bandplan and appropriate types of emission are also included in the introductory part. The frequency synthesis module is discussed in the second part of the document. Emphasis is placed on the direct digital synthesis method (DDS) using modern Analog Devices circuits. The proposed DDS module includes a high-speed clock source. The description of an intermediate frequency module with a demodulator is also placed there. The final part in devoted to the design of a transceiver control panel with a graphical display, a keyboard and a rotary encoder. The firmware for an ATmega128 microcontroller is described in detail at the end of the thesis.

At first this thesis is dealing with the basic principles of network analyzers and afterwards goes to propose conception of a polyscope, as a special type of the scalar network analyzer, designed for magnitude frequency response measurement of two-port devices. As a result of this part of the thesis is the polyscope's block circuit diagram and also selection of key integrated circuits for sweep generator, logarithmic detector and control circuits. As the following part of the thesis is a design of the all basic analyzer's circuits resulting in their schematics diagrams and printed circuit boards, do assembly of all modules and mechanical construction of the instrument and look of the front panel. Some of the tasks is implementation of the firmware and personal computer application able to download measured data from the circuit analyzer via USB and generate chart in Microsoft Office Excel book.

The aim of this work was to design a control system based on the XMega microcontroller, for a small mobile robot with an tracked undercarriage. At first, my work was to develop an electrical scheme and circuit boards for the control system. The next step was to connect sensors for non electric quantity and modify the control algorithms for a simple navigation. In the last phase I tuned the user interface and the whole control system for minimal data flow between the mobile platform and the user interface.

The theme of this thesis is the design of peripheral devices of a smart home SmartFlat and the design of communication interface for this system. Designed units are the humidity and temperature measuring unit, the unit of security and the smart socket unit for remote control, power measurement and power control. All units are designed for wired communicaton and also for wireless communication with control unit.

This study deals with power supply for network devices using existing structured cabling. Various power supplies are analysed including their limitations and also deals with measuring of the consumed energy. The outcome is 24-port passive PoE injector for remote power supply of network equipment. It's suitable namely for remote devices which lacks built-in PoE support as these do not need major modifications (using passive injection). Power options including current measurement may be done via administrative web interface.