The global energy transition poses significant challenges for urban infrastructure as it necessitates robust sustainable energy systems. In the Staatsliedenbuurt Oost neighbourhood of Hilversum, Netherlands, the grid is experiencing congestion due to a convergence of factors: rising electricity consumption from electric vehicles (EVs) and heat pumps (HPs), and the intermittent nature of local solar generation. This situation complicates the neighborhood's ability to reduce its dependency on fossil fuels. This thesis aims to determine optimal, economically feasible configurations for a multi-carrier energy distribution system for a block in the neighbourhood to meet projected energy demand by 2030, reduce grid dependence, and quantify its CO² emissions reduction potential.
A linear programming (LP) model was developed to minimize the net annual cost (NAC) of the system, optimizing the capacity of solar photovoltaics (PV), battery energy storage systems (BESS), air source heat pumps (ASHPs), and seasonal thermal energy storage (STES). The model utilised 15-minute resolution, simulation data and incorporated scenario-based analysis for varying EV and HP adoption rates, including an ambitious "Net Zero" scenario that eliminates grid import. Block 7 was selected for detailed analysis after an initial optimization across 14 neighbourhood blocks.
For Block 7, under a 50% EV and 50% HP adoption scenario, the optimal configuration included 121.467 kW_p Solar PV, 36.801 kW BESS power, 151.602 kWh BESS energy, 55.782 kW_th ASHP, and 526.053 kWh_th STES. This configuration achieved a NAC of €50,792.02, with grid-related costs forming the largest portion. The system demonstrated a degree of autarky (DoA) of 48.06%, with a levelized cost of electricity (LCOE) of 0.362 €/kWh and a levelized cost of heat (LCOH) of 0.120 €/kWh_th. Increasing EV and HP adoption generally led to higher unit costs and increased grid reliance, along with a decrease in DoA. The "Net Zero" scenario achieved 100% DoA but at significantly higher costs (€1.857/kWh LCOE, €0.634/kWhth LCOH) and an extremely high PV curtailment rate (PVCR) of 88.97%. Environmentally, the system showed substantial greenhouse gas (GHG) emissions reduction potential, saving 32,834 Kg CO² equivalent in the base scenario, which rose to 93,516 kg CO² equivalent in the Net Zero scenario.
This research provides a practical framework for mitigating energy challenges in urban environments, contributing to a more resilient, sustainable, and cost-effective local energy ecosystem. It addresses critical research gaps by offering a holistic techno-economic assessment of total residential energy demand within a specific national context, and by exploring the synergistic integration of diverse energy storage technologies and comprehensive sector coupling.

This thesis presents the design and characterization of a low-temperature plasma reactor for seed treatment applications, with a focus on the generation of ozone. The research will look at two different setups using dielectric barrier discharge (DBD) to generate plasma. The first design explores a coaxial tube setup, and the second design entails a multi-hollow plate setup. This research was done in collaboration with TU Delft and the Dutch seed distribution company Bejo Zaden BV, and its main objective was to develop a sustainable and efficient alternative to conventional seed disinfection. The initial tube design used an acrylic tube as the dielectric and two stainless steel electrodes, but this design had some issues so a revised design with smaller dimensions was made to address these issues. The multi-hollow plate design used two steel electrodes with holes (with diameters ranging from $1-2.5mm$) and a dielectric made of polylactic acid. The experimental results showed that both setups work. In order to assess the final design, a program of requirements was made, which included requirements such as sustainability, safety, and scalability. Key findings suggest that the electrode and dielectric materials were not optimal, but were sufficient enough to prove the concepts. This study aims to advance the sustainable agricultural practices by providing an efficient plasma-based seed disinfection method. Future recommendations include optimizing electrode and dielectric materials and scaling the system for industrial use.

A modular approach to high-precision current amplifiers benefits lithography machines by reducing size and increasing efficiency. This research proposes two promising controller structures for a modular topology: a parallel controller structure and a cascaded controller structure. The study evaluates and compares their performance, introduces Delta-Sigma (DS) Analog-to-Digital Converters (ADCs) as a cost-effective alternative, and investigates their limitations in the proposed controller structures. A Feed Forward (FF) strategy is introduced to enhance the frequency response performance of both controllers.
Two methods to increase efficiency, particularly in amplifiers that are using interleaved Pulse-Width Modulation (PWM), are introduced: Phase-Shedding (PS) and Zero-Voltage Switching (ZVS). By estimating power losses it is shown that PS increases power efficiency for lower current setpoints, while ZVS increases efficiency for higher current setpoints. The study investigates how these methods impact controller stability and output current performance.
A hardware implementation validates the operation of the two controller structures. Stability issues with the cascaded controller structure become apparent and are resolved by a method that sacrifices bandwidth. Various measurements are conducted, and their results are compared to analytical expectations. The best frequency response is obtained using the parallel controller structure with a complex FF strategy, which gives a magnitude response of -0.3 dB and a phase shift of -3.6° at a 400 Hz setpoint.
When comparing the two controller structures, each has its own advantages and disadvantages. Choosing between the structures should be based on specific application requirements. If the application requires large bandwidth with high stability, the parallel controller should be selected. If the application requires good modularity, low quantization noise, and disturbance rejection performance, the cascaded controller should be selected.

This thesis presents the development of a frequency-dependent model for metal oxide surge arresters (MOSAs) to better understand their behaviour under temporary overvoltages with a high harmonic content. This topic has gained importance due to the increasing use of long AC cables in connecting offshore wind farms to the transmission grid, which introduces a high capacitance to the grid and raises the risk of harmonic resonances. These resonances can lead to sustained temporary overvoltages, making accurate arrester modelling essential for selecting appropriate surge arresters to withstand these conditions.

Surge arresters are critical components for protecting high-voltage equipment from overvoltage events. The main objective of this work was to investigate the response of the arrester under both AC and DC voltages at a variety of frequencies, with particular focus on the low-current region of the characteristic voltage-current (V-I) curve.

To achieve this, High-voltage AC and DC tests were performed on a surge arrester block. The measured data were used to extract the resistive and capacitive components of the current, as well as to calculate the power losses. These results formed the basis for developing a four-branch nonlinear model. Curve-fitting techniques and various algorithms in MATLAB simulations were used to determine the model parameters, which were then validated against the experimental data. The model demonstrated good accuracy for peak voltages up to 9 kV and showed clear frequency-dependent behaviour, particularly in the 50 to 500 Hz range.

Overall, the final model aligned well with the RMS values of total current as well as the average power losses, with only minor deviations from the measured results. This work contributes to improving surge arrester modelling and lays the groundwork for further developments in frequency-dependent modelling within simulation tools such as ATP-EMTP.

With the rapid growth of Agri-photovoltaic (Agri-PV) systems, a spectral analysis that provides high-resolution data becomes necessary. For such a precise application, there is a need for a spectral irradiance sensor. However, for better precision instruments such as spectroradiometers that are available on the market are expensive. So, in light of this information, the thesis aimed to design and simulate a spectral irradiance sensor’s circuit. The goal was to obtain a PCB design for a high-resolution sensor, suitable for Agri-PV and to simulate the designed circuit to confirm the working theory on which the circuit was made. The circuit was designed on ALTIUM designer where the sensing unit and control unit were separated. The sensing unit consisted: photodiodes and amplifier circuits. The control unit consisted of: ADC and a microcontroller (Raspberry Pi) for signal conditioning and analysis. This circuit was then analyzed and validated through PSPICE OrCAD software. The designed PCB of the Sensing unit contains six photodiodes, which increases the resolution of the spectral sensor. These photodiodes could help in collecting data for a narrow wavelength band (say, approx 10nm width) with the help of bandpass filters. As the PCB was designed while keeping in mind the previous casing’s dimensions of the available PVMD sensor (so the new PCB design can fit on it). Hence, this study finds that it is possible to design a cost-effective spectral sensor circuit that is suitable for Agri-PV applications.

This thesis investigates switching transients in a test system comprised of a single-core underground cable, vacuum circuit breaker, and (Y-Y) star transformer. This work presents six scenarios in which test systems are connected to the transformer in different load scenarios such as no-load, medium and high loads, low and high capacitance, and a combined impedance-capacitance case. Monte Carlo simulations have been employed to introduce random variability into the parameters of vacuum circuit breaker(VCB) to enable probabilistic analysis of extreme transients. Using EMTP and MATLAB software, the study confirms how probabilistic transient analysis can be utilized to improve power system reliability and design protective switchgear.

Cascading failures in power networks pose a significant threat, capable of escalating from isolated line outages to extensive blackouts with severe economic and societal impacts. The topic presents a probabilistic framework designed to assess and compute the risk of cascading failures within the power network and rank various cascade contingencies, utilizing the IEEE39 bus 10-machine New England Power System. Using DigSILENT PowerFactory, a detailed contingency analysis was conducted, focusing on line loading conditions following faults as a starting point. This approach operates under the foundational assumption that cascading failures can be effectively modelled through the sequential analysis of line contingencies. Central to this framework is assessing topological vulnerabilities in the grid and determining frequently occurring outage patterns called probabilistic contingency motifs (PCMs). By analyzing the characteristics of the grid, an impact metric is proposed using short-circuit analysis, electrical distance and LODFs for the identified cascade contingency. The outage probabilities and the proposed impacts are used to compute the risks of cascade cases.

After ranking based on their associated risks, high-risk contingencies are dynamically simulated through time-domain simulations to assess dynamic security. This simulation approach validates the model's predictions and ensures that ranked contingencies reflect realistic cascades. Use cases can show that the model will enable Transmission System Operators (TSOs) to implement preventive measures and simulate corrective actions effectively. By systematically identifying and incorporating PCMs and leveraging grid topology, the model estimates the likelihood and impact of cascading events and delivers actionable insights for improving power system robustness. Future work will expand the framework’s scalability to larger and more complex networks and integrate real-time data streams to facilitate dynamic risk assessment and proactive mitigation strategies.

The pressing need to mitigate global warming and transition to sustainable energy solutions has accelerated the development of innovative energy systems. This thesis investigates the sizing and design of a photovoltaic thermal (PVT) system integrated with aquifer thermal energy storage (ATES) within a fifth-generation district heating network (5GDHN) for a case study in the Werfgebied district in Hilversum, Netherlands. The study focuses on the configuration, storage distribution, and optimisation of component sizing within the district heating network to minimise overall electrical power usage, thus reducing grid dependency and CO2 emissions. A Python model of the multi-energy carrier system is developed, embedding the physical principles underlying the thermal and electrical properties of the components. The research finds that an optimal configuration for the ATES and PVT combination involves a single ATES well rather than distributed thermal energy storage. The results indicate that the size of the aquifer significantly affects the overall operating temperature and its fluctuations. A larger ATES maintains a stable but relatively colder temperature. Optimal sizing is achieved at the maximum allowed operating temperatures of an ATES in these areas, resulting in the most favorable temperature for maximum COP in the heat pumps. This minimises grid exchange and CO2 emissions. The optimal ATES size is determined to be 380,000 m3, in combination with 800 PVT modules, leading to a total CO2 equivalent emission of 856 tonnes.

As the global community seeks to improve current energy technologies for a sustainable future, offshore PV systems show great potential to overcome the land use limitations of traditional PV systems. There is a complex interaction between different environmental forces at sea with the PV structure. Empirical studies on these environmental interactions can provide critical insights to optimize the design of offshore PV systems. This thesis has identified a gap in wind loading studies on offshore PV designs. The primary objective of this research is to develop a methodological approach for studying the wind-induced tilt variations in floating PV (FPV) systems, with the intent of informing future PV performance assessment frameworks. A numerical modelling approach using the CFD tool ANSYS Fluent is adopted as the base methodology. The first phase of the study employs single-phase wind tunnel models in 2D and 3D to study flow behaviour over the required geometry. The models are validated against literature and used as the basis to construct a multi-phase model to simulate wind flow over a floating body and how it moves in response to the water surface.

The model is used to perform sensitivity studies on wind speed, module orientation, module tilt, and floater height. The simulation results indicate that tilt variations induced by wind flow are minimal, under 5◦, for still water conditions. In addition, it also suggests an increase in wind velocity increases the non-linearity in the rotational response of the body, changes in the direction of rotation depending on the speed of the flow and tilt of the module, and a sharp increase in rotation with an increase in floater height. The highest rotational response of 4.07◦(anticlockwise) was observed for a design tilt of 24◦ and a wind speed of 40 m/s.

Based on the simulation results, a PV yield assessment is done, and it is found that the inclusion of tilt effects changes the yield by less than 0.5%. Given the high computational cost involved, a numerical approach for wind load evaluation is not justified in terms of yield variation. For future work, it is recommended to first conduct experimental studies to verify the effects of wind loading on different FPV system designs. This could be supplemented with numerical approaches in the future using high-performance computational resources.

This master’s thesis investigates the design, challenges, and protection mechanisms of electrical power distribution systems on ships with a particular emphasis on DC distribution systems. A key focus is on the challenges of DC systems, including protection difficulties and unique characteristics, as well as their environmental benefits and contribution to sustainability. The thesis dedicates a significant portion to the technical analysis of short-circuit currents in DC grids, offering methodologies for their calculation and protection devices like fuses and circuit breakers. Relevant standards such as IEC 61660 and IEC 60269-1 ground these discussions, ensuring their practical relevance. The thesis includes a detailed simulation model of the DC grid of a vessel, developed using MATLAB-Simulink. The simulation analyses several scenarios, including short circuits and different operational modes, by examining crucial system components such as generators, IGBTs, batteries, drives, and link capacitors. The simulations  showcase the efficacy of protective measures by examining the performance of fuses and circuit breakers in different scenarios. The simulation results of the DC grid's performance under different short circuit scenarios, with and without protective measures, provide valuable information for optimising these systems for maritime applications. The thesis concludes with an improved Simulink model incorporating enhanced battery protection, demonstrating the potential for increased safety and reliability in shipboard DC power distribution systems.

The increasing expansion of the electrical network accentuates the need for a better understanding of the quality of the existing infrastructure. Assessing the quality of the individual cables becomes instrumental in prioritizing replacements and grid reinforcements within the network. A critical evaluation of insulation quality in paper insulated lead covered cables is important to ensure a robust electricity grid. Moisture plays a key role in the degradation of the paper insulation. In this thesis a novel microcontroller based near-infrared spectroscopy system design is proposed which is able to measure the moisture content of paper insulated lead covered cable insulation with a theoretical accuracy of about ±1% moisture content, while being cost effective and portable. It achieves this accuracy by making use of an outlier detection algorithm which is able to increase the accuracy of the system from ±3% to ±1%, by removing outliers of individual sensors and averaging the results of multiple measurements. The resulting output of the algorithm is linked to the asset number of the paper insulated lead covered cable under test, and uploaded to the cloud to enable further data analysis. The proposed near-infrared spectroscopy system performs measurements on one particular absorption band of water; the absorption band around 1450 nm. Due to the influences of stray light, a design of a paper insulation sample holder is proposed. This sample holder is customized to the used components in the design and fixes the samples in place, which limits measurement inconsistencies. A testing procedure is proposed to link the sensor output to the moisture content of the paper insulation sample. A linear relation is found between the sensor output and the moisture content of the paper insulation samples at a moisture content of 0% to 20%.

Voltage source converters (VSCs), particularly modular multilevel converters (MMCs), play a pivotal role in modern power grids due to their application in interconnected systems and renewable energy integration. However, their complex internal dynamics and control systems can cause stability issues under a variety of operating conditions. Impedance-based stability analysis is critical for understanding these interactions and ensuring grid reliability. Traditional small-signal models based on physics and circuit analysis often neglect nonlinearities and practical implementation details, limiting their accuracy. In contrast, black-box impedance measurement techniques necessitate significant computational resources and human effort, particularly when analysing both AC and DC side impedances.

This thesis presents a transfer learning framework for accurate impedance characterization of MMCs. The framework uses a combination of linear time-invariant (LTI) modeling and black-box impedance measurements to estimate impedances based on system-level parameters such as AC and DC side voltages, active power, and reactive power. The methodology involves pre-training artificial neural network (ANN) models on a diverse dataset derived from LTI models, followed by fine-tuning with real-time electromagnetic transient (EMT) simulations. Unlike traditional approaches, which use a single ANN model across the entire frequency range, this study discusses the use of multiple smaller ANN models tailored to specific frequency ranges and operating points, which improves prediction accuracy.

The effectiveness of the proposed transfer learning framework is demonstrated with a practical MMC converter from the CIGRE B4 DC grid test system. The results show that impedance estimation outperforms traditional ANN methods even in scenarios involving confidential converter parameters. This approach allows for precise impedance characterization while reducing computational complexity and data requirements.

Multilevel inverters are widely used in industries for higher power applications due to low harmonic pollution and high efficiency. On the other hand, the phase-shift switching technique is well-known for its harmonic mitigation performance. However, phase-shift switching has not been regularly implemented on multilevel inverters due to complexity at a higher number of levels and difficulty in voltage balancing of the auxiliary capacitors in the configuration. In this project, the five-level Packed U-Cell inverter (PUC5) will be investigated to design and implement a phase-shift switching technique with an integrated voltage balancing algorithm. The developed technique will be implemented on the real-time simulator and hardware setup.

A literature review will be done on phase-shift switching algorithms and multilevel inverters. Afterward, a phase-shift switching algorithm with an integrated voltage balancing technique will be developed for the PUC5 inverter and simulated in Simulink. Hardware-in-the-loop (HIL) will be done using Opal-RT devices.

Drones -- small (or not so small) remotely controlled flying devices -- are seeing rapidly increasing use in many fields of application and human activities ranging from recreation, competitive sports, last-mile logistics, espionage, exploration, to media production, and even warfare. The abundance of these devices brings with it the risk of them becoming an audible nuisance due to the high pitched noise produced by their surface-mount (SM) PMSMs.
The acoustic noise produced in these motors is the product of multiple factors, but chief among them is the vibration of the motor's external shell, which is the stator for internal rotor type motors and the rotor for external rotor type. This shell vibrates in various oscillation modes as a result of the magnetic forces acting on it, which are an inevitable result of the motor's internal magnetic field and the armature currents that produce them.
This motivates research effort into reducing this noise through modulation or control strategies employed by the inverter powering the motor. In order to develop a control model, first the motor itself must be understood. In this thesis, the electromagnetic aspect of surface-mount-PMSMs will be developed, i.e. an analytical model will be established of the air gap magnetic field in SM-PMSMs.
First, the armature reaction field for arbitrary winding types will be derived, followed by a detailed derivation of equations typically used to model the rotor magnets in SM-PMSMs. A derivation of the effect of stator slotting on the air gap magnetc field will be provided, and concluded with a combination of the three previously mentioned aspects, and the dimension of time will be incorporated in the model.
Accompanying this thesis will be a set of MATLAB code that will be made publicly available for research and instruction in academia.

The focus of this report is the design and implementation of a universal gate driver for half-bridge circuits. This design includes a programmable dead-time controller and adjustable properties to ensure efficient and reliable switching on a variety of high-voltage applications. Furthermore, this work includes a comparative understanding of all design choices, such as the options considered for the dead-time controller, the gate driver component and the circuit of the output phase. The designed system is expected to receive as input a PWM signal and generate two output signals to drive a halfbridge configuration. The output pulses must be generated with a programmable dead-time and at the input switching frequency. The end product of this design will be used in the TU Delft Power Electronics Lab. The specific requirements are determined in order to meet the lab’s needs and this report further describes the process from acquiring the technical requirements, the circuit design, and finally, the prototype evaluation.

The number of satellites launched every year is ever-increasing. Satellites generate energy through solar panels, transferring it to the satellite hub using Slip Ring Assemblys (SRAs). However, SRAs suffer from limited lifetime and operating voltages. Therefore, this research investigates a Contactless Energy Transfer (CET) system for the satellite to eliminate these problems. The system consists of an input source, inverter, Alternating Current (AC)-link and rectifier. A single diode model is introduced for the solar panel input source to model its behaviour. After a brief comparison, the Inductive Power Transfer (IPT) method is favoured over the Capacitive Power Transfer (CPT) method. As a result, the AC-link includes a transformer to obtain the contactless energy transfer. The Single Active Bridge (SAB) topology is chosen after comparing the characteristics of the SAB and Dual Active Bridge (DAB) topologies. Afterwards, two SAB converters, the Single Active Bridge with Output Inductor (SABL) and LLC converter, are compared before choosing the LLC converter. With the CET system design completed, the design procedure for the LLC converter is presented, resulting in transformer requirements. A coaxial solenoid transformer design procedure where the inductance and losses are modelled is used to create a prototype transformer. The models are validated using Finite Element Method Magnetics (FEMM). The designed transformer met the inductance requirement. However, the losses were too significant to meet the overall CET system efficiency requirement.

Submodules are the building blocks for MMC-type HVDC converters and therefore of utmost importance for converter reliability. In order to unlock smarter maintenance strategies for submodule semiconductors, the technical condition of the semiconductors needs to be estimated to form a health index. Besides the non-project-specific traditional health index methods, a complete practical implementable data-driven lifetime estimation approach for individual converters is needed to determine the exact remaining useful lifetime of all submodule semiconductors. The methodologies should finally explore a new research direction in the optimization of the converter lifetime considering maintenance intervals. This thesis presents a health index methodology applicable to submodule semiconductors in modern MMC-type HVDC converters. The ON-state collector-emitter voltage is used as a condition indicator and external influences are neglected with electrical and thermal models. These models are needed to estimate the junction temperature in the submodule semiconductors due to the temperature-dependent ON-state collector-emitter voltage. A novel lifetime optimization methodology is presented that determines the submodule that is near its end-of-lifetime and should be replaced in the next maintenance interval. In order to optimize the converter lifetime, the selected submodule is switched more frequently based on a selection window generated from the submodule insertion vector. Switching this submodule more frequently can ensure that it fails exactly at a determined time instant and allows other submodules to be switched less frequently extending their remaining useful lifetime. Finally, a complete data-driven lifetime estimation methodology has been described that uses available measurements in existing MMC-type HVDC converters. Based on the converter load profile and the semiconductor specifications, estimations are made on the submodule semiconductors’ lifetime. Simulations show the significant influence of the DC-pole current based on different voltage class semiconductors and their limitations considering the minimum required lifetime.

As demand for clean and renewable energy around the world increases, solar photovoltaic (PV) technology becomes substantially popular, especially in low-voltage (LV) distribution networks. However, the integration of PV in LV distribution networks requires careful planning as it introduces voltage violations. To maintain network voltage, distributed control of residential-scale battery energy storage systems (BESS) is a possible option. Previous studies considered only one-day simulations with limited testing conditions. However, it is important to evaluate voltage control capability over an extended period of time. Moreover, it is important to estimate battery lifetime for the economic feasibility evaluation of distributed control.

This work aims to present a distributed control method for BESSs at a residential scale to provide voltage support in a highly PV-penetrated LV network while providing insights into their lifetime estimation. A control method based on a consensus algorithm with the addition of SOC balancing control is proposed and tested on a modified CIGRE LV distribution network using MATLAB/Simulink. Evaluations on the voltage support capability and control behavior are performed in various testing conditions and are extended beyond one day of simulation. Moreover, a battery lifetime estimation is performed using the resulting cycling profile from the proposed control.

The proposed control strategy can provide voltage support in most case variations with the exception of cold seasons and extreme addition of PV power generation. Concerning battery lifetime, there is only a small observable capacity fade from the proposed strategy’s cycling profile. It is important to investigate calendar aging because of the small cycling current from the operating conditions presented in this work.

As the electricity sector transitions towards a low-carbon future, an increasing proportion of synchronous generation in the power system is replaced with inverter-based resources (IBRs). The result is a reduction in the available rotational inertia in the grid, depleting its ability to withstand and arrest frequency changes following disturbances. Consequently, disturbances such as a loss of generation or load have an increasingly larger impact on the system, resulting in higher frequency deviations and increased rate of change of frequency (RoCoF).

On two occasions in 2021, the Continental Europe Synchronous Area (CESA) experienced system splitting events caused by cascading trips of several transmission system elements. In both cases, system defence plans were activated in order to preserve the integrity of the overall system. The amount of disconnected load was limited on both occasions, however, should similar events occur in the future with even lower rotational inertia in the grid, the impact could be more severe. This raises the question of whether the existing defence measures are sufficient to maintain system integrity and stable system operation.

Currently in CESA, containment of system frequency excursions following a severe loss of generation is achieved through low-frequency demand disconnection (LFDD) at a frequency below 49Hz. Due to the reduction in traditional synchronous generation and system inertia, the frequency stability of the system is expected to deteriorate, leading to an elevated impact of major disturbances, a rising probability of forced disconnections at frequencies below 49 Hz, and the potential for cascading loss of generation and blackout events.

The objective of this research is to explore the potential impact of reduced system inertia and increased penetration of renewable generation on the performance of the traditional LFDD scheme. In conjunction, additional proactive measures are proposed and investigated with the aim to reduce the probability of LFDD disconnections, by taking actions at frequency thresholds between 50 and 49Hz, as well as to improve the performance of the LFDD scheme in the event that disconnections are required. As a test case, the LFDD scheme as currently applied by one of the distribution system operators in the Netherlands is considered.

This project is therefore categorised in two primary research directions: (i) improving selection criteria for LFDD load shedding locations, and (ii) improving LFDD performance using alternative load shedding schemes.

Key topics explored in this research include: (i) the use of system strength and real-time DER generation as input parameters to load bus selection criteria for LFDD, and (ii) proactive RoCoF-based disconnection of pre-determined consumers above 49Hz. The findings of this study indicate that adapting the current LFDD implementation based on the local system strength and the level of active DER generation at LFDD buses can improve frequency response and reduce instability following LFDD switching operations. Furthermore, proactive RoCoF-based demand side load management techniques above 49Hz prove effective in reducing frequency deviation during the most severe events while avoiding LFDD over-shedding for smaller contingencies.

This thesis presents a practical topology for achieving highly efficient dual-side wireless power transfer (WPT). Traditional WPT systems with a diode rectifier on the secondary side lack flexibility in load matching, requiring the integration of an additional dc/dc converter at the back end. However, this approach leads to increased power losses and costs. In contrast, this thesis proposes the use of an active rectifier comprising MOSFETs, replacing the diode rectifier.

By employing a dual active bridge topology with dual-side control, optimal load tracking is achieved by tuning one side and communicating the desired duty cycle or phase angle to the other side. To address practical challenges, two key aspects are considered.

Firstly, synchronization is established between the generated current on the
secondary side and the new active rectifier, enabling efficient load tracking and the potential for zero voltage switching (ZVS). This is accomplished using a printed circuit board (PCB) equipped with zero current crossing detection (ZCCD), validated with an 85kHz test signal. The PCB triggers the PWM output of the secondary side microcontroller with a latency of less than < 50ns, utilizing the trip-zone digital compare sub-block integrated into the TMS320F28379D.

Secondly, seamless wireless communication between the primary and secondary sides is essential. While the secondary side can measure
the current and voltage across the load to adjust its duty cycle for optimal conditions, the primary side lacks this information. Therefore, the secondary side transmits the new duty cycle to the primary side to
ensure consistent power flow. The nRF24L01+ wifi module is utilized as a dual-purpose transmitter and receiver for achieving wireless communication. Validation of this wireless communication is performed
by remotely controlling an external LED, connected to the receiver side, from a distance of approximately 5m.accurately to the transmitted values. Additionally, a mathematical modeling approach is used to optimize power delivery and mitigate high-frequency noise by incorporating two parallel MLCC capacitors on a custom PCB near the nRF24L01+ module.