This thesis investigates the design, modeling, and testing requirements of Medium Frequency Transformers (MFTs) for Solid State Transformer (SST) applications, with a focus on insulation coordination, thermal performance, and compliance with international standards. SSTs are gaining traction as a next-generation solution for power distribution, offering size and weight reduction, galvanic isolation, and seamless integration with renewable and bidirectional power systems. Central to their viability is the MFT, which must withstand high-frequency electrical and thermal stresses.

A 25kW, three-phase MFT operating at 1kHz was designed using copper windings and a Metglas core, achieving 98% theoretical efficiency and a target mass of 50kg. Detailed electromagnetic and thermal models were developed and validated through experimental testing on a single-phase air-core prototype, assessing insulation withstand, partial discharge behavior, and thermal rise.
The thesis also evaluates IEC 60076-11 as a baseline for MFT testing. While many procedures remain relevant, modifications are necessary to reflect high-frequency effects and pulsed excitation typical of SST systems. Recommendations are provided for adapting key tests to SST environments. This work contributes to bridging the gap between traditional transformer practices and the emerging demands of solid-state-based power conversion, supporting the future standardization and deployment of SST-compatible MFTs.

Transformers are widely used in power electronics but their low operating frequency typically makes them bulky. Increasing the switching frequency can significantly reduce transformer size, weight, and production costs, which is particularly advantageous for portable applications such as chargers. This report investigates the operation of high-frequency transformers and presents the design and development of a working prototype operating at up to 3MHz.
Electrical parameters, including inductance, capacitance, and resistance, were measured using a Bode 100 vector network analyser (VNA) and validated through analytical models and finite element simulations in COMSOL Multiphysics. Based on these parameters, a transformer model was constructed using IEEE Std 390 [1] and verified in LTSpice against measured results. Toroidal cores made of soft ferrite materials in various sizes were evaluated, and round copper wire was initially used for windings. To minimize AC resistance at high frequencies, litz wire was selected for the final prototype. The completed transformer was integrated into a switching circuit operating at 1.5MHz, demonstrating successful high-frequency performance and practical viability.

The increasing integration of renewable energy sources and distributed generation necessitates stringent testing of critical power grid components to ensure system reliability and safety. This thesis addresses two principal challenges: the high-current testing of protection relays and the high-frequency waveform testing of energy meters. Protection relays must withstand extreme fault conditions, with standards like IEC 60255-27:2023 mandating tests with currents up to 100 times the rated current for one second (thermal stress) and 250 times for half a power cycle (dynamic stress). Concurrently, the proliferation of power electronic devices introduces high-frequency harmonics (supraharmonics) in the 2 kHz to 150 kHz range, which can severely compromise the accuracy of energy meters. Conventional test equipment struggles to meet these demands, as high-current transformers are typically bulky with high leakage inductance, while generating high-fidelity, high-di/dt waveforms is limited by existing switching technologies. To address the challenge of high-current generation, this research details the design, simulation, and construction of a compact, low-leakage-inductance current transformer. The design process involved a comprehensive methodology, including core material selection (nanocrystalline AMCC1000), winding optimization, and validation using COMSOL Multiphysics and MATLAB/Simulink. A key innovation of this work is the implementation of a parallel-core configuration. By arranging multiple identical C-cores in parallel, the effective leakage inductance and winding resistance are significantly reduced. This novel approach enables the generation of high-magnitude transient currents exceeding 800 A with the rapid rise times required for dynamic withstand tests, a feat not achievable with a conventional single-core design under similar size and input power constraints (230 V, 32 A). For the testing of energy meters, this thesis explores the development of a versatile high-frequency current waveform generator. A proof-of-concept system was designed and implemented using an Hbridge inverter (L298N module) controlled by an Arduino microcontroller with custom firmware. This lowpower prototype successfully generated a variety of complex, high-di/dt current waveforms, including trapezoidal and phase-fired sinusoids, which are essential for evaluating the susceptibility of energy meters to supraharmonic disturbances. The results validate the inverter-based methodology and lay the groundwork for a future high-power implementation using advanced Gallium Nitride (GaN) devices and DSP-based control, which will overcome the limitations of the current prototype. In conclusion, this research contributes novel and practical solutions for the comprehensive testing of modern power system components. The developed parallel-core transformer provides an efficient method for high-current relay testing, while the waveform generator demonstrates a flexible approach for assessing energy meter performance under non-sinusoidal conditions. Together, these advancements support the development of more robust and reliable equipment, enhancing the stability and accuracy of evolving electrical networks.

This report covers the design of a high voltage power supply that is designed for seed disinfection applications using plasma activated water (PAW). The goal is to have a safe and reliable pulse power supply that can be used to power a Dielectric Barrier Discharge (DBD) load. Multiple setups were designed and analyzed. Different transformers were designed and compared with differing core dimensions, inner radius, number of windings and type of winding. Furthermore, a bipolar driver was built and tested. The results demonstrate that the current design is a solid foundation for small-scale plasma-activated water generation and that it can be scaled with a segmented setup consisting of multiple smaller loads. Future iterations should focus on improving thermal dissipation, switching efficiency, and transformer insulation.

This thesis delves deeper into the design and implementation of a high-frequency DC to DC converter, focusing on the driving circuitry of a transformer based power conversion system operating at MHz frequencies. Because of more demand for smaller, lighter and more energy efficient designs, high-frequency transformers have become an interesting and promising alternative to the standard lower frequency topologies. The project investigates two different topologies, namely: a self oscillating circuit and a GaN based full-bridge inverter. Each of these accompanied by a rectifier stage.

The final prototype successfully operates at a frequency of at least 1 MHz, generating a sinusoidal waveform at the output of the transformer. The system also meet the requirements for achieving an efficiency of 80%, and design criteria such as load independence, compact size and a minimum input voltage of 50 V DC. However, the output power has not reached the desired level of 50 V at 2 A.

The project stresses the importance of precise timing and dead time control in high-frequency switching. While the self oscillating circuit showed promise in LTSpice simulations, it was not pursued due to its dependency on the load connected. Future work should be done to explore an improved component integration, and more advanced control strategies to reach the full 100 W output capability.

High-voltage direct current (HVDC) has established itself as the leading technology for long-distance transmission, particularly for interconnections between countries and offshore wind farms. Sulfur hexafluoride (SF6) has traditionally been the preferred insulating medium in gas-insulated substations (GIS) due to its excellent dielectric properties; however, its high global warming potential (GWP) remains a significant drawback. Partial discharge (PD) detection serves as a critical diagnostic tool for ensuring the operational reliability of GIS systems. This study investigates the long-term PD behavior of protrusion and free metallic particle defects in HVDC GIS filled with technical air. The PD apparent charge magnitude and repetition rate evolution are analyzed using pulse sequence analysis (PSA) plots. Results indicate that PSA plots evolve and vary depending on the defect type, posing challenges for human experts and machine learning models in defect classification. Furthermore, most existing PSA plots are derived from test conditions using SF6, highlighting the need for research in alternative insulation gases such as technical air. Both conventional and unconventional PD detection methods were employed within a full-scale GIS test cell. The two defect types were subjected to voltage application for one week. The free metallic particle defect exhibited a 20% change in PD apparent charge magnitude over the test duration but showed minimal alterations in weight and physical structure. In contrast, the protrusion defect experienced a 30% increase in PD apparent charge magnitude, accompanied by significant physical changes, as revealed through microscope imaging. The observed changes in PD behavior after just one day of voltage application suggest that long-term testing in technical air is unnecessary. Similarly, PSA patterns from SF6 were successfully used to classify defects in technical air, demonstrating that knowledge transfer is possible. Finally, the similarities between the certain patterns of free metallic particles and protrusion defects in technical air highlight the need for further investigation in different test environments to refine defect classification in future studies.

The future power grid must accommodate large-scale integration of variable renewable energy sources. Power electronic (PE)-based components, e.g. onverters, will play an essential role in the operation of the power system. However, the harmonics and transients generated by these PE-based components can significantly affect the lifetime and reliability of various power system components. These disturbances, particularly harmonics and transients, are challenging to eliminate. Thus, a more effective strategy is to assess the effects and enhance the durability and performance of the system components. To ensure the reliability of critical system components, these should meet stringent specifications and undergo rigorous testing prior to installation. Using a modular cascaded H-bridge (CHB) based high-voltage arbitrary waveform generator (HV-AWG), capable of replicating the dielectric stresses induced by PE components, enables a more accurate assessment of component resilience under operational conditions.
The CHB-based HV-AWG can be divided into several submodules; each module consists of three key components: a driver, a medium-frequency transformer, and an H-bridge equipped with HV rectifiers. Although various types of HV-AWGs exist, the modular CHB-based HV-AWG excels due to its superior high-voltage capability, broad operating frequency bandwidth, simple topology, compact size and low manufacturing costs. To successfully realize the CHB-based HV-AWG design, several technical challenges must be addressed, including the development of the insulation system for the medium-frequency transformer and the design of the highvoltage switch within the H-bridge....

AC power transformers are one of the most sophisticated technologies in electrical engineering. However, they have some drawbacks facing volume-sensitive or weight-sensitive applications and energy conversion situations. The solid-state transformer is a promising power electronic technology that can solve the requirements of these applications. It utilizes power electronics and medium frequency (MF) transformers to achieve high power density and multiple functions in energy conversion. With the development of semiconductor switches, it is possible to handle medium voltage in the MF range (1kHz to 1MHz). Therefore, as an essential part of solid-state transformers, medium voltage high power medium frequency transformers require validated tools to model and optimize their design, which is the goal of this thesis. There are several challenges in designing such transformers. They include multiphysics models, Litz wire models, insulation design and design optimization, which are addressed in the thesis....

Heavy industry is responsible for about a third of global emissions but lags behind in its effort to become carbon neutral. The electrification of industrial processes is a necessary step to achieve this goal. The asphalt industry is a good candidate for decarbonisation, as it currently relies on burning fossil fuels to heat and dry the aggregate used in asphalt production. Instead, aggregates could be heated electrically by using induction heating.

This thesis will investigate the design of an aggregate induction drum heater. A COMSOL model will be developed to aid the design process and predict the heater behaviour. The heater will be powered by a resonant converter, which is modelled in Simulink. A test setup is built to serve as a proof-of-concept for the design and to experimentally verify the models.

The analysis of the simulation and test results show that the model quality is dependent on the description of the material properties. The COMSOL model predicts the temperature of the middle of the heater with reasonable accuracy while the Simulink model is able to simulate the coil current and converter voltage waveforms with little error. The design of the aggregate induction heater could be improved by thermally insulating the outside surface and increasing the contact area between the aggregate and the heater.

This thesis investigates the design, analysis and testing of medium-voltage planar transformers for modular Solid State Transformer applications, with a particular emphasis on insulation for medium-voltage level. The renewable energy and microgrid implementation in the generation and distribution segments of power grids is motivated by the global urgency of the energy transition, particularly in response to the challenges in the Netherlands related to the phase-out of natural gas and grid congestion. Central to this work is the development of modular Solid State Transformers (SSTs) tailored for microgrid applications which are one of key components in the transition to more sustainable energy, for which planar transformers in high-frequency operations have to be designed.

A thorough review of high-voltage planar transformer design is conducted, focusing on core and winding losses, parasitic elements, and the complexities of achieving sufficient insulation within compact designs. The thesis outlines the design of a high-frequency planar transformer optimized for modular SSTs, highlighting key aspects such as core selection, loss minimization, and insulation design. Simulations are performed to assess the impact of high-frequency effects on transformer performance, with particular attention to the optimization of winding and shield configurations for improved field distribution and reliable insulation.

Multiple critical aspects in the design of insulation are pointed out and the experimental work is dedicated to testing these aspects.The PCB-based insulation under high-voltage conditions, with a focus on partial discharges and breakdown voltage in scenarios involving parallel conductors within a PCB layer. The results demonstrate the robustness of PCB insulation while revealing challenges posed by surface discharges and the effects of external conditions such as oil and air. These findings provide critical insights into the dielectric performance of FR4 laminates, contributing to the enhancement of insulation system reliability in planar transformers.

The outcomes of this research offer valuable contributions to the design and optimization of high-voltage planar transformers, underscoring the importance of balancing compactness, efficiency, and reliability. These advancements are essential for the development of resilient and sustainable energy systems in the context of the global energy transition.

The world is currently undergoing an unprecedented energy transition from fossil fuel-based energy sources to renewable energy sources. Additionally, advancements in power electronics technology have made High Voltage DC (HVDC) the most cost-effective method for long-distance electrical power transmission over both sea and land. These developments have led to an increased presence of Power Electronic Interfaces (PEIs) in the electricity grid. The insulation of High Voltage (HV) equipment in the electrical power grid is subjected to various electrical stresses due to the solid-state switching of PEIs. This can weaken the dielectric material of the HV equipment and therefore reduce the reliability of the electrical power system. Conventional test sources cannot replicate complex waveforms. Therefore, it is necessary to develop an Arbitrary Waveform Generator (AWG) capable of testing HV equipment with complex waveform shapes. A Modular Multilevel Converter (MMC) is a promising topology for this purpose, where each submodule (SM) requires auxiliary power to supply the Gate Drive Units (GDUs) and Distributed Control Units (DCUs). The objective of this thesis is to design the Auxiliary Power Supply (APS).

This thesis proposes using a flyback-based Input Series Converter as an APS. The proposed converter offers advantages such as integrated active Input Voltage Sharing (IVS), a scalable design, wide-input operation, and a minimal component count. The proposed converter topology is compared with other topologies discussed in the literature through SPICE simulations. Furthermore, various synchronous switch driving methodologies are studied and compared, given the necessity of series-connected switches with the currently available devices on the market.

A critical aspect of the design of a flyback-based Input Series Converter is the multi-winding transformer; hence, this thesis places special emphasis on the electrical and mechanical design of the flyback transformer. The transformer provides HV insulation between the SM capacitor and the output of the APS, as well as active IVS for balancing the voltage across the input stage capacitors and the MOSFETs. A prototype of the multi-winding transformer has been developed and used to assemble an open-loop converter. The converter's performance is tested with an input voltage range of 300V–3600V, and the design is further refined with an output diode snubber circuit.

A scalable, compact, and reliable topology has been identified for an HV-wide input APS for an MMC-based AWG. The topology provides suitable HV isolation between the SM capacitor and the APS output, as well as between the gate pulse generator circuit and the APS power stage. However, the transformer winding design led to a mismatch in leakage inductance between the different converter primary side stages. This resulted in a slight discrepancy in the voltage shared between the series-connected MOSFETs during the converter's turn-off stage. Future work should focus on employing a winding design that ensures equal coupling of all primary windings to the secondary winding in the flyback transformer. Additionally, it is recommended to use a coupled inductor-based passive LC snubber rather than an RCD snubber across the primary windings to introduce an active IVS process during the turn-off stage of the converter as well.

One fifth of the global carbon dioxide (CO2) emissions can be attributed to the transportation sector. Consequently, the growing desire to participate in the energy transition begs for the exploration of alternative modes of transportation. This endeavor is particularly challenging in the field of aviation and aircraft propulsion, where the injection of electrification and electric motors (EMs) pose many hardships such as the need for high autonomy, light weight, high power density and reliability. This work will mainly focus on the latter.

Unlike the low voltage machines used in road mobility, the motors necessary to propel an airplane demand substantially higher voltages due to their power requirements. Despite the availability of dielectric materials and insulation techniques, an improper design of the insulation system may make it susceptible to electrical stress, possibly reaching its breakdown voltage, generating partial discharges (PDs) and degrading the insulating material overtime. This will eventually lead to the electrical failure of the machine.

This danger is further increased by the recent rise in popularity of new wide-band gap power electronic devices. These devices offer many advantages: reduced size and weight, the ability to operate in higher temperatures, and the improved efficiency due to the reduction in power losses, caused by their steep switching speed in the order of 10−100 ns. However, the steep voltage transients (dv/dt) they produce create harmful side-effects to the machine. Firstly, the feeder cable connecting the voltage inverter to the machine terminals suffers Reflected Wave Phenomenon (RWP), where the voltage pulses are reflected at both ends of the line generating intereferences, which in turn generate overvoltages that can rise to up to twice the original voltage pulse. Secondly, the inherent leakage capacitance between the cable turns and the core of the stator slots produce an uneven voltage distribution along the wiring turns. These effects could increase the voltage stress in the insulator and momentarily reach the breakdown voltage in certain points of the geometry, producing Partial Discharges (PDs) that degrade the insulation over time.

To avoid this degradation, the aim of this thesis is to study these harmful effects in depth, back-up the literature review with accurate simulations and experimentation and realize the worst case scenario considering the geometry of a given motor that is currently under design. Once the phenomena is understood, some mitigation techniques are proposed to lower the chance of any discharge occurring.

This thesis investigates the impact of geometric, material, and operational parameters on the electromagnetic fields (EMFs) emitted by submarine power cables, particularly those used for offshore wind power transmission. The study is essential due to the growing deployment of offshore wind farms and the corresponding need for efficient submarine power transmission systems, combined with ecological concerns. The primary focus is on high-voltage alternating current (HVAC) cables, commonly used to connect offshore wind farms to the onshore grid. The rapid expansion of offshore wind power has highlighted significant ecological and environmental concerns, especially the effects of EMFs on marine life. Species such as elasmobranchs (sharks, rays, and skates) are highly sensitive to EMFs, making this an important area of research. The objective of this thesis is to develop guidelines for modeling EMFs from submarine power cables to aid ecological research, focusing on establishing effective parameters for EMF emission models. A literature review has shown that EMFs can impact marine animals’ navigation, predator-prey relationships, and embryo- genic development. Elasmobranchs, in particular, are vulnerable due to their sensitivity to EMFs. The review highlights the necessary accuracy levels for EMF models, focusing on HVAC cables. Starting with the basic physics including Maxwell’s equations, the Biot-Savart law, and the Lorentz force, followed by an outline of HVAC cable and transmission system design parameters, an understanding was created of the electromagnetic phenomena occurring in a submarine power cable. It was concluded that modeling EMFs requires considering current distribution along the conductor and metallic sheath, and the local interactions between cable components that result in shielding of the EMFs. A method from literature was used for predicting the longitudinal distribution of current along the conductor. The current distribution was affected by voltage and current transmission requirements, impedance, and the capacitive and inductive properties of the phases as well as reactive power compensation. Analyzing these parameters showed that all are crucial for accurate EMF modeling, as parameter changes within realistic ranges could result in differences over 10%. A significant part of this thesis examines the intensity of the metallic sheath currents. Modern HVAC cable designs use conductive polyethylene layers around the metallic sheaths, creating an electrical interface between them. This was conventionally assumed to dissipate circulating currents in the sheath, but this thesis questioned this belief. It was proven that some circulating currents remain and that induced currents were even unaffected by the conductive interface. The induced currents in the metallic sheath are shown to only be influenced by the conduction current and its design parameters, inductance, and resistance per unit length. Testing on the Borssele Alpha cable showed that sheath current for all standard operations was more than 12% of the conduction current. An analysis of the local impact of various design and operational parameters on EMF emissions was conducted using COMSOL Multiphysics. The Borssele Alpha 1 cable design served as a standard test case. The analysis highlighted the importance of the metallic sheath and even more so, the armor layer. The steel armor layer created a path of low reluctance, with geometric parameters and permeability playing significant roles. The effect of twist in the phases and armor wires on field emissions was also shown. The lay-length of the phases played a large role due to its effect on destructive interference between emissions of different phases. The armor lay-length had a considerable impact as well, possibly affecting the reluctance of the armor layer. The parameter analysis also confirmed the validity of an ultra-shortened section length in COMSOL, greatly reducing simulation time without impacting results. This research provides insights for developing accurate EMF emission predictions, aiding biologists and ecologists in evaluating the environmental impacts of offshore wind power infrastructure. This can guide the development of mitigation strategies and support sustainable expansion of renewable energy sources. Recommendations for future research include experimental testing of the sheath current model, further development of the transmission line method for the metallic sheath and developing better mitigation strategies. Unrelated to the main question is that in thermal analysis of comparable submarine power cable designs, the induced current must be incorporated, as it was unclear if this is the case. The findings of this thesis can significantly contribute to the sustainable growth of offshore wind power by addressing ecological concerns and improving the understanding of EMF effects on marine life.

Unwanted breakdown of insulation is one of the primary challenges affecting the reliability of power systems. Liquid insulation is commonly used in power grids and subsea installations due to its preferred qualities, such as heat transfer and safety. Some insulating liquids have been available since the earliest times, and some have been proven to be harmful to humans, animals, and the environment. Consequently, the search for better candidates has always been ongoing. Unfortunately, the knowledge of the quality of the insulating liquids is insufficient since numerous phenomena related to electrical discharge and breakdown in insulating liquids happen unexpectedly, often surprising the personnel involved. Therefore, gaining a deep understanding of the breakdown physics of these liquids and mechanisms leading to the degradation of their dielectric properties is crucial. This understanding ensures that the new replacements are suitable for specific equipment. Partial discharge (PD), as one of the initial stages before breakdown and a major player in ageing the insulators, is the main focus of this work. One way to monitor a liquid’s insulation quality is through the Partial Discharge Inception Voltage (PDIV)
level. Based on PDIV measurements, there are defined standards, such as IEC 61294. This work is focused on investigating the behavior of different types of liquids under the AC voltage stress above and below the PDIV level to determine if the defined standards reflect the dielectric characteristics of each liquid properly. Three liquids have been examined, including two candidates from commonly used insulating liquids in electrical installations. Tests are performed in a needle-plane geometry under high-voltage AC stress. The same liquids and geometry have been used multiple times in previous studies under lower frequency AC voltage, yielding unexpected results. Therefore, this study aims to investigate deeper by testing the liquids at higher frequencies and comparing observations with previous results. The experimental setup used for this work includes a 20 kV resonance voltage source, and the needle-plane gap distance is 20 mm. The current flow from the plane to the needle is mostly capacitive in the range up to 100 nA, but space charges are proved to play a major role in the conductive component of the current. PD behavior has been found to relate to molecular structure and, in some cases, to the previous stresses, likely due to residual ions remaining from previous cycles. The presence and nature of space charges have been investigated carefully by testing liquids at higher frequencies below and above the PDIV level. Further, the test setup was facilitated, and half-cycle voltages were applied to involve only one polarity of space charges, and the differences were observed. Another part of this work involved the optical PD measurement method, which utilized two photomultiplier tubes (PMTs) and a coincidence circuit to filter out ambient dark noise. This method was employed alongside the well-known charge acquisition method to detect the initial PD pulses in the liquid. The results demonstrated a noteworthy difference between the two methods, prompting further investigation.

The thermal rating of power cables is a critical aspect of electrical cable design that determines their safe operational limits. Traditional rating methods rely on worst-case assumptions for weather conditions, such as constant ambient temperatures or steady-state loading with a 100% load factor. Given the significant thermal masses and variations in ambient conditions, these assumptions often do not reflect actual operational scenarios. As the integration of fluctuating renewable energy sources into power systems increases, the dynamic nature of these systems becomes more pronounced. Consequently, the thermal rating of the power cables must be considered dynamic to accommodate these changing conditions. In this thesis, an improvement of dynamic cyclic rating predictions is explored for cable temperatures using the Finite Element Method (FEM). This improvement is performed by incorporating detailed weather and environmental data into the model. The study begins with a comprehensive literature review that provides an overview of existing dynamic rating systems and their applications. Subsequently, an analytical and numerical thermal model was developed and compared with COMSOL and CIGRE standards. It is concluded that the developed numerical model demonstrates greater accuracy and usefulness. This numerical model is integrated into a web-based tool called Ampwise, which serves as the basis for all future improvements. Cable data from the Windpark Fryslân project is used to validate the predicted temperature against the measured cable temperature. The research demonstrates that incorporating weather data significantly improves the precision of dynamic cyclic ratings, especially the inclusion of the real external air temperature and solar radiation of the location. Validation of the predicted conductor temperatures against measured DTS cable temperatures from the Windpark Fryslân project showed a mean absolute error (MAE) of 1.9 °C and a root mean square error (RMSE) of 2.3 °C. These results show the enhanced accuracy and reliability of the dynamic cyclic ratings when real weather data are incorporated. However, the rate of change in the real temperature is significantly higher than the predicted temperature, leading to short-term differences between the predicted and actual temperatures. In addition, a sensitivity analysis is conducted to assess the impact of various factors. The analysis highlights the importance of correct initial conditions, particularly ground temperature gradients and seasonal environmental variations. The thesis concludes that integrating weather and environmental data into dynamic rating models is crucial to achieving reliable and precise cable performance predictions over an extended period, thus supporting better operational decisions and infrastructure management.

This paper presents the design and development of an Electrical Discharge Machining (EDM) device aimed at achieving precise hole creation in diverse metal materials. The EDM device was conceptu- alized and constructed based on specific requirements identified by the group. The design process encompassed four main stages: dielectric fluid selection, electrode design, control system develop- ment and power supply. In the dielectric fluid stage, the importance and criteria for selecting an appropriate fluid were discussed, resulting in the choice of distilled water for its superior dielectric properties. The electrode design stage followed a similar methodology, leading to the selection of a copper rod as the optimal electrode material. The control system stage detailed the development of an open-loop, manual, and closed-loop control system, emphasizing the utilization of Klipper software for precise electrode control. The power supply section outlined three primary circuits: the power source, power amplification circuit, and square wave generator circuit. Detailed schematics, component justifications, and optimization values for key parameters were provided to enhance power supply efficiency. Experimental evaluation demonstrated the capability of the EDM device to effectively create holes in various metals using an open-loop control system. Additional experiments focused on parameter variations within the power supply setup further illustrated their impact on machining performance. The discussion highlights the challenges encountered throughout the project, particularly the constraints imposed by limited time, which prevented the realization of all initially set requirements. Despite these challenges, the EDM device successfully met most of the specified objectives, showcasing promising results for future refinements and applications in precision machining.

The goal of this project is to create a power supply for an electrical discharge machine (EDM). This machine can drill holes and create shapes in metal objects by evaporating material using discharges from the electrode to the workpiece. The electrode should be supplied with a high-voltage pulse wave in order to initate sparks. The power supply produces this waveform by turning a DC source on and off using a transistor as a switch. A current-limiting resistor that is placed between the source of the MOSFET and the electrode prevents short circuits during discharges. The circuit was first created with a DC voltage of 15V. A gate driver circuit to drive this MOSFET was designed to reduce power losses and to make the frequency and duty cycle adjustable. Then the design was improved by adding a diode to remove oscillations caused by the parasitic inductance of the power resistor. Afterwards, the circuit was built on a custom PCB to reduce parasitics. A filtering capacitor was added to remove high-frequency noise, after which a stable 15V pulse signal was obtained. A microcontroller is employed to regulate the pulse duration, detect spark occurrences, and relay this information to a speed regulator. This establishes a closed-loop system aimed at optimizing the overall system operation. To achieve this, circuitry is employed to convert the power supply output into a digital format, enabling the utilization of the microcontroller’s specialized hardware for rapid sampling.

In this thesis, "Design & Reliability Assessment of AEA Propulsion Grid", the development of a reliable and efficient propulsion grid for All-Electric Aircraft (AEA) is investigated to reduce aviation emissions. Our primary objective is to design a lightweight Power Management and Distribution (PMAD) system that meets stringent reliability standards. By analyzing materials, heat transfer, and grid design, we propose optimized grid topologies that balance weight and reliability. The findings emphasize the importance of redundancy and suggest further research into subcomponent failure rates, control aspects, and real-world testing to enhance system reliability and performance. This thesis provides valuable insights into the future of electric aviation, highlighting the necessity for continued investigation and practical application to ensure ultra-reliable electric propulsion systems and make zero-emission flight a reality.