Ebook: Power, Energy and Electrical Engineering

The 14th International Conference on Power, Energy and Electrical Engineering (CPEEE 2024) was successfully held from 24 to 26 February 2024. The objective of CPEEE 2024 was to provide an interactive forum for the presentation and discussion of power, energy, electrical engineering and related fields.

CPEEE 2024 provided a scientific platform for local and international scientists, engineers and technologists working in all areas of power, energy and electrical engineering to explore technical interests, as well as socializing and sharing things like culture and history. In addition to the contributed papers, internationally known experts from several countries were also invited to deliver keynote and invited speeches at CPEEE 2024. These were Prof. Le Yi Wang (Life Fellow of IEEE, Wayne State University, USA), Prof. Mohamed Benbouzid (IEEE Fellow, University of Brest, France), Prof. Masafumi Yamaguchi (Toyota Technological Institute, Japan), Prof. Marc A. Rosen (Engineering Institute of Canada, Canada) and Prof. Koki Ogura (Kyushu Sangyo University, Japan). The conference consisted of 8 oral sessions (6 offline and 2 online). Online presenters were tested in advance to ensure the success of their delivery at the conference. The whole conference was also recorded for backup purposes.

This conference provides an excellent opportunity for researchers, scientists, and engineers from different parts of the world to share the latest knowledge and findings on a variety of topics, including distribution systems and the optimized configuration of distribution networks; status monitoring and reliability evaluation of power equipment; operational safety and energy consumption analysis of intelligent electrical equipment; development of electric vehicles and the construction of charging facilities; photovoltaic modules and power generation systems; clean energy generation and electricity storage; intelligent power systems and electronic technology.

This final proceedings of CPEEE 2024 includes 57 papers, all of which were selected after a thorough review process. We are grateful to the authors and the participants, as they are both key to the provision of an ideal forum to exchange results and ideas. We would also like to express our sincere gratitude to our colleagues from the relevant disciplines who kindly volunteered to participate in the review process. Special thanks go to the conference organizers and session chairs for their commitment to developing a strong technical program and enjoyable social events. It is our hope that this proceedings of CPEEE 2024 will result in increased collaboration among researchers in related fields, and will also help in facilitating the exploration of novel cross-disciplinary ideas.

On behalf of the organizing committee, we hope that your participation in this conference will prove fruitful. We will continue to organize this conference in the future to provide an effective platform for the exchange of new knowledge and perhaps a seedbed for potential collaborations in the research areas of power, energy and electrical engineering.

Prof. Mingcong Deng

IEEE Fellow, Tokyo University of Agriculture and Technology, Japan

Publication Editor

This manuscript presents a novel method for optimal placement of shunt capacitors in a power distribution network. Installing shunt capacitor banks to a distribution power system has been proven to have positive effects on power loss reduction, voltage regulation, power factor and the overall efficiency improvement. Leveraging convex optimization, the proposed technique minimizes the copper loss on the feeder, while achieving the desirable voltage regulation performance. Computer simulation results are summarized to prove the effectiveness of the method. This novel approach improves the existing capacitor placement methods by providing the optimality and flexibility to both regulate the voltage levels and reduce power losses.

To enable local energy trading in the distribution network, a market operator and a system operator are required. The market operator is in a character of business model and responsible for market clearing. The system operator supervises the network in order to operate according to market clearing results. In this paper, the function of the system operator is focused. Since, the market participants bid the price and the quantity of power based on their benefit, a challenge for the system operator is how to manage if there is a congestion problem. For this purpose, a bus transfer factor is developed. It is a factor that reflects the change of power in the line compared to the change of generation power in the bus. This factor can use as a sharing factor for increasing or decreasing the generation power of market participants. To validate the bus transfer factor method, the study case is provided. A comparative result between the proposed method and the load curtailment method shows that the proposed method can solve the congestion problem with the minimum adjustment.

This study focuses on the development of an energy management system (EMS) for a microgrid (MG) that prioritizes balanced demand-supply operation to accommodate the stakes of distribution system operator (DSO), consumers (CNSs), and aggregator (AGR). An innovative EMS model for MG is introduced, which integrates power interchange (PIC) through electric vehicle aggregation tracks (EVATs) within virtual distribution feeders (VFs). This model enables each PIC to determine its contribution to different areas and corresponding remuneration simultaneously. The research presents a problem formulation for leveling operations using mixed integer linear programming (MILP), explaining operation scheduling through case studies. The results demonstrate the economic disadvantages for CNSs and AGR of completely leveling of net load powers by DSO’s directives. Additionally, it is emphasized the significant role of PIC through EVATs, particularly in microgrids with surplus power of photovoltaic (PV) systems and less capacity of battery energy storage systems (BESSs).

Distributed Generation (DG) embedded with Distribution Networks (DNs) has been developed because its performance has become more efficient and sustainable. This reconfiguration mode increases the short-circuit current (SCC), and subsequently heightens the complexities involved in both the setting and operation of the overcurrent protection system. Therefore, it is necessary to develop a robust protection strategy for DNs integrated with DG to prevent the electrical equipment from collapsing during abnormal conditions. This study proposed one of the most important and reliable strategies for resetting and re-coordinating overcurrent relays (OCRs) that operate in the same protection zone of the distribution feeder. This methodology restricts the main variables and elements used in the protection device (PD) setting after DG is embedded to redesign a suitable setting and coordination. However, international, and national benchmark standards are used to specify suitable equations that satisfy high-protection system characteristics to ensure the reliability of DNs according to a real case study of a medium voltage level 33kV in the electrical distribution feeder of Baghdad, Iraq.

The primary objective of this research is to design a three-phase distribution transformer that reduces technical losses within the electrical distribution system. These losses translate into costs associated with energy dissipation. While it’s impossible to eliminate these losses entirely, the aim is to optimize system efficiency. The focus is on the 220 V secondary voltage level. The research resulted in a transformer with losses of 4.6882 W, which complies with IEEE standards. The design features a cruciform morphology, operates at 13.2 kV, and has a total surface area of 9660 mm2. The core material is mu-metal, and the coil material is copper. The applied design methodology includes a 2^∧4 factorial design, and simulation is performed using ANSYS Maxwell, evaluating sixteen combinations. The design with the lowest power loss is selected as the optimal choice, effectively reducing technical losses in the electrical system.

This paper focuses on controlling reactive power output using passive filters capable of supplying reactive power to mitigate overvoltage conditions in distributed power systems, aiming to enhance voltage stability. In a case study, the IEEE-34 bus model was utilized, and changes in voltage at various locations within the distribution network were observed after integrated photovoltaic as a inverter based resource. Using a Python-based COM interface integrated with OpenDSS, the reactive power output was regulated, and in response to changes in reactive power output, the passive filter was readjusted. As this paper primarily emphasizes reactive power, the effects of harmonic removal were not emphasized. To validate the control approach, voltage fluctuations at all buses were monitored within OpenDSS, confirming the results and demonstrating the effectiveness of this method.

As renewable energy increases, the demand for substation construction also needs to increase simultaneously. Before a substation is built, its environmental magnetic field assessment is particularly important to people’s health, and most of this environmental magnetic field assessment is only for the outside of the substation. In recent years, the safety and health of occupational personnel have been gradually valued, so the assessment of the environmental magnetic field inside the substation is also very important. Finite element analysis (FEM) is currently most commonly used for accurate environmental magnetic field assessment. However, its calculation consumes a lot of time and computer resources. Therefore, this study proposes a simplified model method for the main magnetic field source inside the substation, that is, the power transformer. This method can not only simplify a lot of simulation time, but also ensure that the overall error of the magnetic field simulation value above 2,500 mG is within 5 %.

This project studies the electric field distribution within an ideal CRDT containing an air-filled void in the epoxy insulation. Insulation is the most important part of high-voltage equipment. They are vital for isolating conductors and for their performance. The electrical field distribution in a CRDT is described by a three-dimensional field model built using SOLIDWORKS 2020. COMSOL Multiphysics 5.5 software was used to carry out the simulation based on the finite element method (FEM). The model is solved for an ideal condition as a base for further analysis. In addition, an air-filled void is introduced into the model of epoxy insulation to investigate the effect of void presence on the electric field distribution within the transformer. The distribution of the electric field is plotted on a graph, and a certain condition has been applied to the transformer, such as varying the void size and locating the void. It was observed that the electric field is 136 MV/m when the void is located near the LV winding, while it is only 0.246 MV/m when it is close to the magnetic core. It can also be seen that the electric field decreased as the size of the void increased. The findings of this study will contribute to a better understanding of the electric field response caused by the size and position of the void within the epoxy insulation, as well as the electric field stress, and may provide a path for future researchers to investigate partial discharge.

By elevating the operational frequency, there exists the potential to diminish the transformer’s size and weight while simultaneously augmenting its power density and efficiency. Nonetheless, this approach is not without its challenges and practical limitations. This research delves into the optimal design considerations for core-type medium frequency transformers. In comparison to their shell-type counterparts, core-type transformers offer significant advantages, including ease of repair and maintenance, more efficient cooling, and superior suitability for high-voltage applications in transmission and distribution transformers. Additionally, we conducted a comparative analysis between copper wire split winding and Litz-wire winding for core-type transformer applications. The utilization of geometric programming facilitates the derivation of an efficient and dependable global optimal solution for the design of solid-state core-type transformers.

Increasing integration of inverter power sources into the electrical power system has raised concerns about a lack of system inertia, leading to potential disturbances in system frequency and speed during grid disruptions. Virtual synchronous generator (VSG) control is a promising solution for inertia support of the electrical power system. VSG’s inertia enhances system stability by eliminating small and occasional disturbances. However, the required system-wide inertia and the appropriate inertia characteristics supplied by individual VSG remain unclear. Also, the power variation in power electronic interface inverters caused by VSG control increases the stress on power semiconductor devices. In this paper, the focus is that VSG’s inertia ensures grid-side stability by removing disturbances and the influence of VSG on the lifetime of power semiconductors. First, temperatures of the IGBTs are obtained from the inverter model considering the thermal model and HILs simulations with small and occasional disturbances. Next, the lifetimes of the IGBTs are calculated from the results of the rainflow analysis of these temperatures, using the linear cumulative damage theory in lifetime prediction. As a result, a trade-off relationship between system stability and IGBT lifetime is confirmed.

Surge arrester is one of the most important equipment to be considered while performing insulation co-ordination studies. Surge arrester, due to its nonlinear voltage – current characteristics, has the ability to bypass the surges and maintain a safe voltage across the power system equipment. This helps in achieving the necessary protection margin for the system. The insulation coordination study considers the protection level offered by the surge arrester for surges of various rise times and magnitudes. The surges are classified as steep current impulse, lightning current impulse and switching current impulse. The residual voltage of the surge arrester increases as the steepness of the surge increases, hence steep current impulses are more severe as this will increase the stress on the power system equipment. IEC 60099-4 defines the methodology to determine the steep current impulse residual voltage by subjecting surge arrester blocks with surges having front time of 1s. In real life, surges can be even faster. In this paper a simple methodology is defined to compute the protection level offered by a 66kV 10kA Station Low surge arrester while bypassing steep current impulse of 500ns front time. The unknown inherent non-inductive drop offered by the arrester blocks is determined and the inductive voltage drop for the arrester is added, to arrive at the protection level. This will be helpful in providing accurate information to improve surge arrester model while performing insulation co-ordination studies for special scenarios.

In the pursuit of sustainable energy solutions, wind power emerges as a pivotal contender. This research pioneers the integration of a Horizontal Axis Wind Turbine (HAWT) into the Eolic Cell—a modular wind energy system designed for augmented wind speed and efficiency. Our primary objective is the holistic optimization of HAWT performance, considering five distinct Tip Speed Ratios (TSR) to account for varying conditions. To optimize turbine performance, we manipulate three key parameters: pitch angles of turbine blades along the radius, the First-Grade coefficient, the Second-Grade coefficient, and the NACA profile chord. A novel Metamodel of Optimal Prognosis (MOP) methodology is introduced, streamlining computational efficiency and facilitating gradient-based optimization across the chosen TSRs. This research marks a significant stride in advancing wind energy solutions for distributed generation, focusing on practical efficiency enhancements. It leverages innovative approaches in wind power generation, laying the groundwork for a sustainable energy future. This article signifies the initial phase of our exploration into harnessing the potential of Eolic Cells as a transformative solution for distributed energy generation, with future research endeavors aimed at validating its practicality.

As a result of the increasing number of electronic devices and limited space on aircraft, the development of high-efficiency and small-sized power supply systems is necessary. The switched tank modular converter (STM) receives attention recently because of its high power density and efficiency, which is suitable for aircraft application. Full soft charging is achieved by connecting a small inductor in series with the flying capacitor compared to the traditional switched capacitor (SC). Zero current switching (ZCS) helps to reducing the power loss of the switches. However, further reduction of the overall size is hampered by the fact that the effect of switches and passive components on the total volume is unclear. In order to find the optimum total volume of the STM, a comprehensive volume modeling and optimization method is proposed in this paper based on the semiconductor power loss and resonant capacitor voltage ripple analysis. A 12V-6V, 10W, 3.85MHz STM prototype is fabricated to verify the proposed optimization method, which achieves 96% peak efficiency at rated power and 51.25 mm³ total volume. Three groups of switches and passive components collocation are designed and the optimum volume group is found while remaining the highest efficiency.

Our study proposes a MATLAB simulation to analyze the hysteresis loss in single-phase transformers under a frequency of 50 Hz, calculating the variables and the relationship between the magnetic flux density (B) and the magnetic field intensity (H) in the theoretical equation to design used in numerous conditions, including consideration of parameter of the ferromagnetic silicon steel core material, sizes, power rated, and amplitude of alternating current (AC) sinusoid that affects the B-H curve, and saturations point in the time domain. Comparing the hysteresis loss characteristics between the model and empirical experiments and the experiment test results are given in this paper.

This study aims to investigate the combustion temperature of a rocket-type ceramic burner when using Compressed Natural Gas (CNG) as a fuel instead of Liquefied Petroleum Gas (LPG) through Computational Fluid Dynamics (CFD) methods. The simulations were conducted using Fluent 2021 R2 with a 3D model, comparing the combustion temperature of CNG with LPG. The results reveal that as the heat input increases, both the flame length and maximum temperature rise. At 30.02 kW, the maximum temperatures obtained from LPG and CNG were 1396 and 1842 K, respectively. Moreover, the maximum temperatures from CNG were consistently higher than those from LPG at all heat inputs. This difference is attributed to the higher primary air intake from CNG, enhancing the effectiveness of premix combustion. Consequently, transitioning from LPG to CNG as a fuel for a rocket-type ceramic burner holds the potential for energy savings and reduced emission.

Utilized thermographic phosphor to evaluate the heat exchange performance of the heat transfer fins. Designed a wind tunnel chamber to evaluate the heat exchange performance of TEG’s heat transfer fins. Preliminary experiments were conducted utilizing an infrared camera to compare results with those taken with a regular CMOS camera. The calibration chamber also designed to determine the phosphors luminescence property to real surface temperature. CFD flow analysis was performed under the same conditions to match the specifications of the experimental device to verify feasibility.

A high-fidelity numerical analysis methodology was proposed for evaluating the fuel rod cladding integrity of a Prototype Gen IV Sodium Fast Reactor (PGSFR) during normal operation and Design basis events (DBEs). The MARS-LMR code, system transient safety analysis code, was applied to analyze the DBEs. The results of the MARS-LMR code were used as boundary condition for a 3D computational fluid dynamics (CFD) analysis. The peak temperatures considering HCFs satisfied the cladding temperature limit. The temperature and pressure distributions were calculated by ANSYS CFX code, and applied to structural analysis. Structural analysis was performed using ANSYS Mechanical code. The seismic reactivity insertion SSE accident among DBEs had the highest peak cladding temperature and the maximum stress, as the value of 87 MPa. The fuel cladding had over 40% safety margin, and the strain was below the strain limit. Deformation behavior was elucidated for providing relative coordinate data on each active fuel rod center. Bending deformation resulted in a flower shape, and bowing bundle did not interact with the duct of fuel assemblies. Fuel rod maximum expansion was generated with highest stress. Therefore, it was concluded that the fuel rod cladding of the PGSFR has sufficient structural safety margin during DBEs.

A comprehensive investigation of the three-dimensional flow phenomena within the wire-wrapped 169-pin fuel assembly of the Japanese loop-type sodium-cooled fast reactor MONJU was conducted through numerical analysis using the widely-used commercial computational fluid dynamics code STAR-CCM+. The intricate vertical flow patterns within the wire-wrapped 169-pin fuel assembly were accurately represented through Reynolds-averaged Navier-Stokes flow simulations, including the turbulent stress transport model. The results of the Computational Fluid Dynamics (CFD) analysis exhibit a favorable alignment with the temperature distribution trends when compared to experimental data. Furthermore, a strong correlation between the temperature distribution of the experimental results and the CFD analysis outcomes was observed, indicating the effective reproduction of the observed temperature distribution within the experimental dataset. This underscores the capability of numerical analysis in faithfully replicating the temperature distribution as observed in the experimental data.

With the acceleration of the digitization process and the continuous growth of data demands, traditional data centers often face issues of low energy efficiency, leading to increased energy consumption and energy costs. The cooling system is one of the main energy-consuming systems in data centers, therefore, energy-saving retrofit of the cooling systems has become a crucial topic, holding significant energy-saving potential. Modeling and optimizing the systems are particularly important for data center energy efficiency. This paper proposes a method to establish a comprehensive dataset for the entire energy-saving retrofit process, providing data support for device modeling.

Novel controllers are introduced in energy system research to alleviate the uncertainties of renewable sources. These have been modified to fit a solution formed in various ways. This article deals with voltage regulation of wind farms in situations of voltage dips in which communication failures occur. The objective is to discuss a modification of the online management system for wind farms. We focus on the voltage regulation of wind farms when communication failures occur in the online wind farm management system. The structure has been designed to respond to a voltage drop when the external reference is absent due to communication errors. A comparative analysis was performed with general control modes to demonstrate the relevance of the proposed method.

This paper analyses an electrification strategy for a depot for a public transport company, through an optimized model. The case study analyses both the transition of a depot able to host 10 buses towards e-buses and proposes the integration of a micro-grid, powered by PV panels to power the e-buses in a sustainable way. The study addresses key challenges such as spatial constraints, passenger demand, and financial considerations, through a Genetic Algorithm (GA). The analysis encompasses two scenarios: a mixed fleet of electric and diesel buses and an exclusive focus on e-buses. The study highlights the importance of considering both electric and diesel buses in fleet optimization, and combined with renewables emphasize the advantages of operational flexibility and sustainability. Thanks to the implementation of a micro-grid capable of providing 1123.87 kWh/day to power the e-buses as much as possible.