Abstracts:Disruptions in ground communications during disasters significantly impede unmanned aerial vehicle (UAV)-based power line inspections, slowing down fault localization and threatening system secure operation. This paper proposes a spatiotemporal precise routing strategy for the integrated satellite-terrestrial network, focusing on achieving stable communication and balanced energy consumption among the UAV swarm under signal fluctuations. Here, satellite internet and flying ad-hoc network (FANET) are fully utilized concurrently, which is tailored to practical demand of post-disaster power line inspections and overcomes communication collapse. The proposed strategy features superior flexibility and resilience in various complex and hostile environments. The simulation results demonstrate that the proposed strategy outperforms traditional routing algorithms, supporting stable signal transmission for multi-UAV-based power line inspections, extending cluster operational time, and enhancing the speed of post-disaster power system recovery.

Abstracts:In modern micro-grid systems, the control of power electronic converters faces numerous challenges, including the uncertainty of parameters of the controlled objects, variations in the operating environment, and the increased complexity of models for controlled objects. Meanwhile, traditional control strategies for power electronic converters are characterized by high model dependency, slow dynamic response, and static control parameters, which make them inappropriate for the development of modern micro-grid systems. In response to this problem, researchers have proposed reinforcement learning (RL) control strategies to achieve fast adaptive control through real-time interaction with the environment. However, there is currently a lack of comprehensive literature reviews specifically focusing on RL control for power electronic converters. To fill this gap, this article provides a summary of existing published research papers. Specifically, the mainstream RL algorithms are listed. The existing RL control strategies for various power electronic converter topologies are introduced. The sim-to-real methods for practical implementation are illustrated. The underlying design considerations are discussed. Moreover, the future research prospects are explored.

Abstracts:Commercial Battery Energy Storage Systems are equipped with a standard control unit with simplified logic, able to reduce the impact of the power system on the electric grid. The standard control is locked in a closed environment without any chance to modify the logic. The control unit receives signals from current sensors located at the entrance point of the power system. This paper presents a proposal of innovative device called Smart Digital Current Simulator as a substitute of those current sensors, aiming to generate a sinusoidal signal that falsifies the real induced current inside current sensor's windings by house power leads, in order to fool the control unit to inject or withdraw the desired electric power from or to the electric system. This paper shows a prototype of the suggested device completed of the open sources Node-Red server, Mosquitto broker and Home Assistant Container. This device communicates through Mosquitto protocol and can be managed by a user-friendly Graphic User Interface with open logics to manage a user-desired charge and discharge. Also, allows complying Demand Side Management and Demand Response strategies, otherwise not possible. Moreover, it is useful to buy energy when the price of electricity is below a specific threshold or the Battery Storage power is preferred instead of the grid power when the price of electricity is above a specific threshold. Finally, is able to perform a peak shaving to keep the withdrawal of power constant from the grid.

Abstracts:This paper presents the design and analysis of a modified volleyball premier league-optimized 3-DOF (FOPI)-FOPD controller for a proactive LFC scheme. The proposed controller incorporates forecasted load demand as one of its inputs. This unique configuration empowers the controller to proactively eliminate the disturbances. To validate the controller performance, a truncated model of the DPS has been developed which is subjected to different load profiles and are assumed to be known. It was observed that the predicted disturbance to the system (change in load demand) is of utmost importance for this proposed configuration. Thus, improved LSTM, incorporating a multi-approach feature selection and DWT has been developed, which is used to forecast day-ahead load demand. This forecasted demand is given as an input to the controller. The dynamic performance of proposed controller is evaluated by subjecting the modelled DPS with proposed controller to standard test signals. The obtained simulation results are also validated through OPAL-RT real-time simulator. The results demonstrate the superior performance and robustness of the proposed LFC approach in maintaining the frequency of the power system within acceptable limits.

Abstracts:Efficient allocation of electric vehicle charging stations (EVCSs) is crucial to promote widespread adoption of electric vehicles, to support sustainable transportation, and to reduce range anxiety. Thus, it enhances energy security and mitigates environmental impact. In this work, EVCSs are optimally distributed across a superimposed road and distribution network with a focus on electric vehicle (EV) user's convenience to reach charging station. The allocation problem has primarily been solved by taking into account nodal cost and vehicular uncertainty. The process also considered minimizing fundamental energy and harmonic losses in the distribution network. The quantity of charging ports is a crucial consideration that is frequently overlooked during the allocation process. Optimal port allocation not only helps in determining the waiting time of each EV user reaching that charging station but also reduces the burden on the distribution network of excessive port in a charging station. In this instance, the cost of installing the charging port is taken into account and optimized. An additional fee to the charging station has been imposed as an additional expenditure for the distribution losses caused by the inclusion of the charging station in the network. The suggested method has been implemented on MATLAB platform and tested on a practical distribution network with 40 buses. Outcomes are encouraging and the methodology may be applied to solve similar problems for practical systems.

Abstracts:Wind Turbine (WT) is one of the main renewable energy sources (RES) in the world. However, if a large number of WTs is connected to a power system, the system inertia will be decreased. Thus, system operators require WTs to support frequency control for assisting the frequency recovery when a disturbance occurs. This study established user-defined models (UDM) in PSS/E for WT's frequency control functions. The typical frequency controls and optimized power point tracking (OPPT) method were investigated and established in PSS/E. Most of the literatures did not consider a complete control structure with adaptive control techniques and wind speed variation. Thus, this study proposed a novel frequency control strategy for WTs based on wind speed variation and OPPT, which can adjust the supporting power from WTs efficiently according to wind speeds, and make WTs effectively utilize their stored kinetic energy. This study also used the real Taiwan power system for simulations, and considered a cascading tripping of synchronous generators and wind speed variations. According to the simulation results, the proposed control strategy improves the system performance on frequency response and surpasses other mature control method.

Abstracts:The integration of Renewable Energy Sources (RES) into the power grid is limited by two inherent characteristics: intermittency and low inertia. These characteristics negatively impact system stability, particularly in terms of frequency stability. If the penetration of RES in a power system exceeds a certain threshold, the frequency stability of the system is compromised. This paper proposes and validates the effectiveness of combining Fault Ride Through (FRT) with Battery Energy Storage Systems (BESS) to address these challenges in various scenarios. Subsequently, the research employs the Particle Swarm Optimization (PSO) algorithm to determine the optimal parameters of both the BESS and Power System Stabilizer (PSS) for all the Synchronous Generators in a microgrid, achieving improved frequency stability. The results reveal the combined application of these two methods proves highly effective in enhancing system stability, even when RES account for 100% of the system's generation capacity.

Abstracts:With the projected penetration levels of distributed generators (DGs) and electric vehicles (EVs) charging load, the power quality of the utility grid will significantly deteriorate, resulting in grid pollution and many non-compliant nodes. Addressing this issue with the conventional load-side filtering-based solution will be uneconomical. Thus, there is a need to develop a cost-effective and improved active filtering solution capable of regulating the harmonic profile with optimal placement of scarce active filters. This paper proposes an optimization-based distributed filtering solution to regulate the harmonic profile of an IEEE 33-bus distribution network. The optimization problem formulation is presented in detail, wherein the cost function is minimized and subjected to voltage and bus THD constraints. Firstly, the impact of adding EVs and DGs on the grid's harmonic profile is quantified, which suggests that the grid harmonics are increased by almost 3%. Secondly, the impact of adding distributed active filters on the overall harmonic profile is presented. The detailed simulation results obtained validate the improvement in the harmonic profile, as the post-filter harmonic profile stays below 4.5% for all operating conditions.

Abstracts:Nanocrystalline and ferrite are two commonly used magnetic cores for magnetic couplers of wireless charging systems (WCSs) in electric vehicle (EV) applications. Considering the advantages and limitations such as loss, saturation, temperature, and weight of those two types of magnetic cores, a hybrid core, with nanocrystalline and ferrite on receiving and transmitting sides respectively, is proposed in this study. Firstly, different topologies are generalized into the form of S-S topology, and the influence of load and magnetic material on the efficiency of the magnetic coupler is analyzed for an S-S compensated WCS. Then, an evaluation method of magnetic materials in WCS is proposed according to the derived optimal load. Based on the simulation comparison and consideration for practical applications, the layout of the proposed hybrid core is proposed. With the genetic algorithm, a detailed design process is given and a design scheme is also obtained. Finally, a prototype with the proposed hybrid core is manufactured for experimental validation. The results show that the efficiency of the magnetic coupler with the proposed hybrid core can reach 95.395% at 20 kHz, which is 2.5% higher and only slightly lower than that of the coreless magnetic coupler and magnetic coupler with ferrite core, respectively.

Abstracts:Nanocrystalline alloy is considered as the potential alternation to ferrite due to its higher saturation flux density and better ductility in application of loosely coupled transformers (LCT) in wireless power transfer systems. However, to reduce the eddy current loss, it generally needs crushing and compressing processes, which may lead to obvious nonlinear characteristics and affect both equivalent conductivity and permeability. In this study, the influence of the nonlinear characteristic on the maximum output power of LCT without saturation is first revealed, at the same time, the influence of the lamination coefficient of nanocrystalline core and its equivalent conductivity on the efficiency of LCT are also analyzed by finite element analysis. Then, a determination method of critical conductivity for LCT with the nanocrystalline core is also proposed. On this basis, a selection method of nanocrystalline material for LCT in the wireless power transfer system is also proposed considering nonlinear characteristics and laminated structure. Experimental validation was performed on 3-kW and 7.7-kW prototypes, and the results show that the nanocrystalline core with higher permeability approaches saturation more quickly as the primary current increases, and the critical conductivity determination method is also verified. In addition, with identical initial permeability, the higher efficiency of LCT can be reached by reducing the lamination coefficient.