Renewable power systems are becoming more affordable and provide better options than fossil-fuel generation, for not only the environment, but a benefit of a reduced cost of operation. Methods to optimize charging batteries from renewable technologies is an important subject for off-grid and micro-grids, and is becoming more relevant for larger installations. Overcharging or undercharging the battery can result in failure and reduction of battery life. The Arduino hybrid MPPT controller takes the advantage of solar and wind energy sources by controlling two systems simultaneously. The ability to manage two systems with one controller is better for an overall production of energy, cost, and manageability, at a minor expense of efficiency. The hybrid MPPT uses two synchronous buck DC-DC converters to control both wind and solar. The hybrid MPPT performed at a maximum of 93.6% efficiency, while the individual controller operated at a maximum 97.1% efficiency when working on the bench test. When designing the controller to manage power production from a larger generator, the inductor size was too large due to the frequency provided by the Arduino. A larger inductor means less allowable current to flow before the inductor becomes over saturated, reducing the efficiency of the controller. Utilizing a different microcontroller like the PIC16C63A produces a much faster frequency, which will reduce the inductor size needed and allow more current before over saturation.

Discrete silicon carbide (SiC) power devices have unique characteristics that outpace those of silicon (Si) counterparts. The improved physical features have provided better faster switching, greater current densities, lower on-resistance, and temperature performances. However, there is lack of suitable commercial gate drivers that are compatible for high-voltage, and high-speed devices. There has been a great research effort required for the advancement of gate drivers for high voltage SiC transistors. A drive circuit for a SiC MOSFET needs to be optimized in normal operation to give best efficiency and same drive circuit should secure the MOSFET under unsuitable conditions. To ensure the rapid switching of these advanced SiC MOSFETs, a gate driver capable of providing the high current capability is required. In this work, three different high-power-density, high-speed, and high-noise-immunity gate driver modules for 10 kV SiC MOSFET were built and optimized.  Double-pulse test was developed for the dynamic characterization of SiC MOSFETs and gate drivers. This setup provided clean measurements of DUT voltage and current under well-defined conditions and correlated to simulation results. Designed gate drivers have thoroughly investigated to test and compare it with our future design. The influential parameters such as dV/dt, dI/dt, and gate driving capability of gate driver were adjusted according to the requirements. The short circuit protection test was performed to check the reliability of driver modules in worst conditions. Furthermore, a DC-DC converter was designed and tested with the advanced gate drivers. The driver modules were tested in designed converter under different load conditions and influential parameters were successfully demonstrated. The driver modules effectively helped in reducing the EMI and switching losses. These designed gate drivers and prototype converter provide all the attractive features and can be widely implemented in industrial applications for energy efficient systems.

This master’s thesis deals with the design and fabrication of DC arc welder supplied from its own rechargeable battery. Battery cells’ type is LiFePO4 which can provide high currents even at relatively low capacity. The BMS circuits are designed within the battery. Major power part of the welder is a step-down converter with synchronously switching low transistors at the position of free-wheel diode. The converter operates at 100 kHz frequency. The current of the battery welder can be regulated in the range from 0 to 120 A.

This diploma thesis deals with design of DC/DC converter which will be used in one-phase inverter powered from batteries. Required parameters are output power of 100 W, input voltage of 24 V and output voltage of 350 V. In the first part is briefly discussed used topology of flyback converter. In the next part is designed impulse transformer with a request to design impulse transformer as small as possible. Thesis continues with draft of power components placed on primary and secondary side of converter. In this thesis is part about limitation of voltage overshoot at turn off transistor. Next part of this thesis deals with the design of control circuits using an integrated circuit from the UC384x family. Thesis continues with the production and debugging of the converter. At the end of this thesis are measurements confirming the correctness of the proposed design.

This master´s thesis describes switch mode power supply and discusses the design of its individual parts. It also contains a simulation of the power part of the converter and a reseach in the area of DC/DC converters.

This thesis is about theory of switching power supplies and about a specific solution of switching power supply for electron microscope. In the beginning of the thesis are mentioned various solutions of part blocks of switching power supplies, their advanteges and disadvanteges, and their suitability for electron microscopy. In the next part of the thesis are described requirements and design scheme of switching power supply for scanning part of electron microscope. The thesis i also about technical solution and practical testing of the switching power supply and verification of its functions.

This thesis deals with design of evaluation platform for integrated circuit NCV78934, which is designed to control LED headlights in automotive industry. The theory concerning the current regulation of buck converter, schematic design, PCB design and software design are also included in the thesis. Finally the measured data and testing procedures of the designed evaluation platform are discussed.

Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states. An artificial neural network learns to mitigate incohesive microinverter and DC-DC converter actions. The DC-DC converter outputs 36 V DC operating within its specifications, but the microinverter drops input resistance looking for the sharp decrease in power that a solar panel exhibits. Since the DC-DC converter behaves according to Ohm’s Law, the inverter sees no decrease in power until the voltage drops below the microinverter’s minimum input voltage. Once the microinverter turns off, the converter regulates as intended and turns the microinverter back on only to repeat this detrimental cycle. Training the neural network with the back propagation algorithm outputs a value corresponding to the feedback voltage, which increases or decreases the voltage applied from the resistive feedback in the DC-DC converter. In order for the system to react well to changes on the order of tens of microseconds, it must read ADC values and compute the output neuron value quicker than previous control attempts. Measured voltages and currents entering and leaving the DC-DC converter constitute the neural network’s input neurons. Current and voltage sensing circuit designs include low-pass filtering to reduce software noise filtering in the interest of speed. The complete solution slightly reduces the efficiency of the system under a constant load due to additional component power dissipation, while actually increasing it under the expected varying loads.

Master’s thesis deals with design and realization of power supply, which is supplied and controlled via USB bus. In theoretical part there are described principles of USB communication drivers which ensures this communication, there are described principles of linear voltage regulators and basic types of DC/DC converters. Mentioned is also PID regulator theory. Practical part aims for design of suitable DC/DC converter topology and creating algorithms for driving this converter. Next there is created PC program which drives power supply and there are also accomplished basic power supply measurements. The result of this thesis is functional power supply supplemented with PCB.

This master's thesis deals with a design and realization of a LED driver that is based on integrated circuits NCV78703 and NCV78723 from ON Semiconductor. The aim of the project is to create a demonstration application with these integrated circuits for the use of company. The circuits can be especially used for driving LED automotive lights. The driver is controlled with a microcontroller also providing a communication with a software running on a PC via USB interface. This software enables to simply modify parameters of the driver in order to adjust an intensity of LEDs.