In the last decade, the progress of personal computer is growing very fast. The frequency of signals on mother boards applies between 33MHz and 1GHz. Due to the high operating frequency, the radiation from the microstrip lines on PCB should be noticed when designing the PCB¡¦s layout. The solution is using solenoidal and rogowski coils which have been investigated for many years. Coils, however, not only can be used in RF inductors, but also induce currents due to magnetic field through the cross section wound in turns. Therefore, coils may be used to induce magnetic field. Using this phenomenon, intensity of currents on DUT(Device Under Test) could be measured as well. In order to make more extensive use, optimization routines on the basis of the model were found. This thesis shows that magnetic field sensors on silicon and PCB can be studied in a better model, simulated by the software, Ansoft HFSS. Simple accurate expressions, an equivalent circuit model, and the transfer impedance are presented. As a result, induction of magnetic field on silicon is demonstrated in the area enclosed by turns, the parasitic capacitance or inductance, and conductor resistance, which is due to the skin effect in the high frequency. Hence, coils can induce large current because of big cross section. We can use it to measure the magnetic field and the currents radiated by the microstrip on PCB. In this thesis, I will show a novel PCB sensor which can measure 100MHz to 4 GHz signals and it has large output signal as well. The advantages of these coils are less disturbing DUT and easy to produce. It proves that we can use these magnetic field sensors to help solving the EMI problems.

In this study, the current densities in three different directions (r, φ and z) have been measured above the target during a HiPIMS discharge by the use of a Rogowski coil. This was done to examine the key transport parameter Jφ/JD┴ = ωge TEFF throughout the whole measured area, which is a key parameter describing how electrons are transported across magnetic field lines. The coil was adapted to the certain plasma environment that is present during a HiPIMS discharge in consideration due to the extreme environment that is present during the experiment. The thin film deposition system, where the measurements were performed, had a background pressure of ~10-6Torr and during the discharges the chamber were filled with an Ar to the partial pressure of 3mTorr. The previously reported anomalous fast transport of charged particles was verified and the faster-than-Bohm cross-B transport was found to be present in the chamber during the whole discharge but occupying a diminishing area closer to pulse turn off.

Thesis (D. Tech. Electrical engineering) --Vaal University of Technology / A comprehensive study upon "Non-conventional methods for energy extraction from the high voltage transmission lines" was addressed in this thesis. As defined in this study, a non-conventional method to extract energy is one that does not touch the conductors of the line. The theoretical framework which originated in the Maxwell's equations was presented as a base for discussion of all the methods and the conditions for the extraction to be possible. This study presents various methods such as capacitive and inductive to extract energy from high voltage alternating current transmission lines (HVAC). Although in theory, for high voltage direct current transmission lines (HVDC), the conditions for extraction are not matched, there remain some methods that could still attract interest. The centre point of this thesis is the new power application of the Rogowski coil. This method is analysed in full extent starting from theoretical modelling, computer simulations, design of the actual Rogowski coil and power electronics associated with it, and experimental results on a reduced scale model. In doing this, strong mathematical tools and computer software such as Matlab 6, Quick Field and MathCAD were used. At the end of this thesis, some conclusions are presented together with new ideas for further research in the field.

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Nowadays, major public concern is concentrated on reducing the usage of fossil fuels and reducing emissions of CO₂ by different energy advancement. Electric vehicle technology presents extremely effective way of reducing carbon emissions and paves the way of having sustainable and renewable energy future. In order to wear the cost of electric vehicles down, batteries have to be improved as well as higher power density and high reliability has to be achieved. This research work mainly focuses on achieving higher power density and higher reliability of the inverter stage by utilizing wide-bandgap SiC MOSFET semiconductor devices in electric vehicle application. In order to achieve higher reliability of the inverter stage, high bandwidth, high performance Rogowski coil switch current sensors are employed. These sensor were embedded on the PCB and integrated on the gate driver. High bandwidth switch current sensor measurement is used for fast short-circuit detection and protection of the SiC MOSFET semiconductor switches. Furthermore, comparison with conventional detection and protection method used in automotive IGBT applications is shown where novel protection showed superior performance. This thesis also shows principle of how to obtain phase currents of the system using Rogowski coil switch current sensor measurements. Digital reconstruction principle is employed to obtain the phase currents. Accurate and linear current sensor is achieved. By successfully realizing this integrated phase current measurement on the gate driver, elimination of the commercial current sensors from the system is possible. By eliminating existing phase current sensors, higher power density could be achieved. Sensor is evaluated in both continuous and discontinuous PWM schemes. / Master of Science / Together with renewable sources, electric vehicle will play an important role as a part of sustainable and renewable energy future by significantly reducing emissions of CO₂ into the atmosphere. In order to make electric cars more acceptable and accessible and make a significant impact on the environment, cost must be lowered down. To wear the cost of the electric vehicles down, powertrain of the car must be significantly improved and made smaller as well as lighter. This thesis mainly focuses on improving the reliability of the motor driving stage by implementing novel protection during fault periods such as short-circuit event. Furthermore, this novel protection allows current sensing that is crucial for motor control during normal operation periods. This will enable more compact motor driving stage since existing current sensing elements can be eliminated.

La mesure de courant dans un environnement industriel est une étape indispensable pour garantir la pérennité d'un réseau de distribution électrique. En général, chaque domaine d'applications (mesure, protection, etc...) nécessitent l'utilisation d'un capteur adapté. Ces travaux de thèse proposent d'utiliser un capteur bas coût principalement dédié à la protection, le tore de Rogowski, aussi comme élément de mesure. Afin d'améliorer sa précision intrinsèque souvent insuffisante, nous avons développé une boucle de correction et une électronique de calibrage intégrée (CMOS 0,35µm) permettant d'adapter ce capteur aux standards métrologiques. Nous détaillons dans ce manuscrit les étapes de l'élaboration de cette boucle de correction ainsi que les résultats obtenus à l'aide des différents prototypes. Nous terminons par la présentation du premier démonstrateur technologique, premier pas vers un système de mesure de courant sans contact de classe 0.1, auto-calibré, autonome et bas coût. / The measurement of the current in an industrial environment is a necessary step to ensure the sustainability of an electrical distribution network. Typically, each application domain (measurement, protection, etc ...) requires the use of a suitable sensor. This thesis work proposes the use of the Rogowski coil current transducer, a low cost sensor usually used for protection, as measuring element. In order to improve its often insufficient intrinsic accuracy, we have developed a correction loop as well as an integrated electronics for calibration (CMOS 0,35μm) to adapt the sensor to metrological standards. In this manuscript, we detail the development stages of this correction loop and the results obtained with different prototypes. We conclude with the presentation of the first technology demonstrator, a very first step towards a current measurement system that would be contactless, 0.1 accuracy class, auto-calibrated, autonomous and low cost.

This thesis deals with measurement method pulsed quantities of electromagnetic field. This thesis was focused on methods, which make use of optic effect. Specially Faraday effect, Pockels effect and magneto-optic Kerr effect. Next it was focused on method makes use of Rogowski coil. At the end was shortly noticed about method makes use of calorimetric sensor. For experimentally realized has been chosen Faraday Magneto-optic Effect. In optic laboratory has been realized absolute methods and different methods making use of Wollaston polarizer on pneumatic optical desk. The main advantage of this method is the capability to measure the high frequency and high current signals. Next in this thesis has been written theory about Rogowski coil. This method has been experimentally realized in laboratory.

This work descibes general principles of measuring the alternating current and voltage using conventional and unconventional sensors.This work shows specific parmeters conected with principles of the measurement, advantages and disadvantages of individual measuring procedures, types of output signals, precisions, limitations, ways of power and so on. Part of the work is to find optimal measurement procedure, which can be aplicated to practical measuring of alternating currents and voltage. Main part of the work concerns the realisation of optimal method of measuring alternating current.

This master’s thesis describes the function and realization of the laboratory test equipment designed for measuring and analysing of collector current iC and voltage uCE courses during the opening and closing process of a power IGBT transistor. The opening and closing times toff and ton of the new power transistor IGBT are changing in the range from tenths to the ones s, so the reading of current iC and voltage uCE proceeds in a very short time. The measuring circuit of this test equipment is based on a short-time discharging of a condenser battery to the inductive load over the measured transistor. Consequently it is possible to replace the power supply whose maximum output power would otherwise have to be in the range of ones MW. In the final part of this thesis there are described properties and design of a high-frequency sensor with the Rogowski coil, which can be used for reading collector current course during opening and closing time of the measured transistor IGBT. Collector current iC and voltage uCE courses can be analysed with a storage oscilloscope.

Current transformers and current sensors are devices which are mostly used for current measurement in high voltage systems. These devices transform measured currents to range which are workable for measurement and protection devices. Theoretical part includes from third to seventh chapter. These chapters contain construction analysis and characteristic points for both device and problems of protecting the transformer with differential protection. Practical part includes from eighth to tenth chapter. This chapter consists results from laboratory measurement. Results are used for verification with theoretical part of the thesis. Conclusion of this thesis comparing properties and summarises results from laboratory measurement.