Earticle

With the rapid expansion of renewable energy deployment, power systems are increasingly exposed to issues such as higher output variability. Photovoltaic generation, as the most widely installed variable renewable energy source both domestically and internationally, exhibits significant fluctuations due to weather conditions. These characteristics lead to operational challenges including increased curtailment, higher reserve requirements, and even risks of large-scale outages. This study aimed to improve the accuracy of photovoltaic power generation forecasting by developing a data quality control procedure for meteorological data collected at a PV plant. The quality-controlled data were used as inputs to SVM and XGBoost, resulting in improved forecasting accuracy, with MAPE decreasing from 7–10% to 6.32% and 6.08%, respectively. The results demonstrate that meteorological data quality control significantly enhances PV forecasting performance and can contribute to distributed energy resource operation and curtailment mitigation strategies.

An efficient reactive power management is important in providing secured operation for a power system in terms of maintaining its stability condition. Lack of safe operating margin and reactive power support were known to cause a system to operate in an unstable voltage condition. Hence, voltage stability improvement must be planned properly so that the likeliness to instability event could be determined before the more severe event of blackout could occur in a system. For that reason, the application of the developed a new optimization technique namely Adaptive Tumbling Bacterial Foraging (ATBO) was to obtain the most possible optimal Reactive Power Planning (RPP) solution. The objective of RPP problem was not only to minimize the total power losses in a system but was also extended in terms of voltage stability and now termed as security constrained RPP (SCRPP). In order to ensure maximum benefit while ensuring secure operating condition and minimum impact to environment, the proposed ATBFO and Multi objective ATBFO (MOATBFO) were utilized to solve for the single and multi-objective for SCRPP issues. The performance of the proposed techniques were comprehensive analyzed between two other familiar optimization methods known as original Bacterial Foraging Optimization (BFO) algorithm and Meta heuristic Evolutionary Programming (Meta-EP) for standard IEEE 57 bus system. From the results it shows that the multi objective ATBFO optimization is able to give better overall improvement among all objective functions of SCRPP.

In the future, hybrid power management systems using fuel cells (FCs) and batteries will be used as the driving power systems of ships. These systems consist of an FC, a converter, an inverter, and a battery. In general, an FC provides steady-state energy; a battery provides the dynamic energy in the start state of a ship for enabling a smooth operation, and provides or absorbs the peak or dynamic power when the load varies and the FC cannot respond immediately. The FC voltage range is very wide and depends on the load; Therefore, the FC cannot directly connect to the inverter. In this paper, we propose a power management strategy and design process involving a unidirectional converter, a bidirectional converter, and an inverter, considering the ship's operating conditions and the power conditions of the FC and the battery. The presented experimental results were verified through a simulation.

In recent, Google proposed the Project Loon being developed with the mission of providing internet access to rural and remote areas using high-altitude balloons. In this paper, we describe an applicable prototype of 5.8 GHz wireless power transmission system with rough beamforming method to Project Loon. From the measurement results, transmit beamforming phased array antenna can transmit power more efficiently compared to a horn antenna and array antenna without beamforming with increasing the transmission distance. For the transmission distance of 1000 mm, transmit beamforming phased array antenna can obtain higher received power about 1.46 times compared to array antenna without transmit beamforming.

This paper discusses a dc motor equipped electric power steering (EPS) system and demonstrates its advantages over a typical hydraulic power steering (HPS) system. The tire-road interaction torque at the steering tires is calculated using the 2 d.o.f. bicycle model, in other words by using a single-track model, which was verified with the J-turn test of a real vehicle. Because the detail parameters of a steering system are not easily acquired, a simple system is modeled here. In previous EPS systems, the assisting torque for the measured driving torque is developed as a boost curve similar to that of the HPS system. To improve steering stiffness and return-ability of the steering system, a third-order polynomial as a torque map is introduced and modified within the preferred driving torques researched by Bertollini. Using the torque map modification sufficiently improves the EPS system.

Power consumption during testing System-On-Chip (SOC) is becoming increasingly important as the IP core increases in SOC. We present a new algorithm to reduce the scan-in power using the modified scan latch reordering and clock gating. We apply scan latch reordering technique for minimizing the hamming distance in scan vectors. Also, during scan latch reordering, the don't care inputs in scan vectors are assigned for low power. Also, we apply the clock gated scan cells. Experimental results for ISCAS 89 benchmark circuits show that reduced low power scan testing can be achieved in all cases.

This study aimed to develop an advanced anomaly-detection system tailored for solar power distribution panels using thermal imaging cameras to ensure operational stability. It addresses the imperative shift toward digitalized safety management in electrical facilities, transcending the limitations of conventional empirical methodologies. Our proposed system leverages a faster R-CNN-based artificial intelligence model optimized through meticulous hyperparameter tuning to efficiently detect anomalies in distribution panels. Through comprehensive experimentation, we validated the efficacy of the system in accurately identifying anomalies, thereby propelling safety protocols forward during the fourth industrial revolution. This study signifies a significant stride toward fortifying the integrity and resilience of solar power distribution systems, which is pivotal for adapting to emerging technological paradigms and evolving safety standards in the energy sector. These findings offer valuable insights for enhancing the reliability and efficiency of safety management practices and fostering a safer and more sustainable energy landscape.

System-On-a-Chip(SOC)을 테스트하는 동안에 요구되는 테스트 시간과 전력소모는 SOC내의 IP 코어의 개수가 증가함에 따라서 매우 중요하게 되었다. 본 논문에서는 수정된 스캔 래치 재배열을 사용하여 scan-in 전력소모와 테스트 데이터의 양을 줄일 수 있는 새로운 알고리즘을 제안한다. 스캔 벡터 내의 해밍거리를 최소화하도록 스캔 래치 재배열을 적용하였으며 스캔 래치 재배열을 하는 동안에 스캔 벡터 내에 존재하는 don't care 입력을 할당하여 저전력 및 테스트 데이터 압축을 하였으며 ISCAS 89 벤치마크 외호에 적용하여 모든 경우에 있어서 테스트 데이터를 압축하고 저전력 스캔 테스팅을 구현하였다.

Testing time and power consumption during testing System-On-a-Chip (SOC) are becoming increasingly important as the IP core increases in a SOC. We present a new algorithm to reduce the scan-in power and test data volume using the modified scan latch reordering. We apply scan latch reordering technique for minimizing the hamming distance in scan vectors. Also, during scan latch reordering, the don't care inputs in scan vectors are assigned for low power and high compression. Experimental results for ISCAS 89 benchmark circuits show that reduced test data and low power scan testing can be achieved in all cases.

The unbalance between system ergodic sum rate and high fairness is one of the key issues affecting the performance of non-orthogonal multiple access (NOMA) system. To solve the problem, this paper proposes a power allocation algorithm to realize the ergodic sum rate maximization of NOMA system. The scheme is mainly achieved by the construction algorithm of fair model based on α fair utility function and the optimal solution algorithm based on the interior point method of penalty function. Aiming at the construction of fair model, the fair target is added to the traditional power allocation model to set the reasonable target function. Simultaneously, the problem of ergodic sum rate and fairness in power allocation is weighed by adjusting the value of α. Aiming at the optimal solution algorithm, the interior point method of penalty function is used to transform the fair objective function with unequal constraints into the unconstrained problem in the feasible domain. Then the optimal solution of the original constrained optimization problem is gradually approximated within the feasible domain. The simulation results show that, compared with NOMA and time division multiple address (TDMA) schemes, the proposed method has larger ergodic sum rate and lower Fairness Index (FI) values.

In this paper, we investigate a power control problem which is very critical in underlay-based spectrum sharing systems. Although an underlay-based spectrum sharing system is more efficient compared to an overlay-based spectrum sharing system in terms of spectral utilization, some practical problems obstruct its commercialization. One of them is a real-time-based power adaptation of secondary transmitters. In the underlay-based spectrum sharing system, it is essential to adapt secondary user's transmit power to interference channel states to secure primary users' communication. Thus, we propose a practical power control scheme for secondary transmitters. The feedback overhead of our proposed scheme is insignificant because it requires one-bit signaling, while the optimal power control scheme requires the perfect information of channel states. In addition, the proposed scheme is robust to feedback delay. We compare the performance of the optimal and proposed schemes in terms of primary user's outage probability and secondary user's throughput. Our simulation results show that the proposed scheme is almost optimal in terms of both primary user's outage probability and secondary user's throughput when the secondary user's transmit power is low. As the secondary user's transmit power increases, the primary user's outage probability of the proposed scheme is degraded compared with the optimal scheme while the secondary user's throughput still approaches that of the optimal scheme. If the feedback delay is considered, however, the proposed scheme approaches the optimal scheme in terms of both the primary user's outage probability and secondary user's throughput regardless of the secondary user's transmit power.

Audiovisual (AV) facilities such as TVs and signage are installed in various public places. However, audio cannot be used to prevent noise and interference from individuals, which results in a loss of concentration and understanding of AV content. To address this problem, a total technique for remotely listening to audio from audiovisual facilities with clean sound quality while maintaining video and lip-syncing through personal smart mobile devices is proposed in this paper. Through the experimental results, the proposed scheme has been verified to reduce system power consumption by 8% to 16% and provide real-time processing with a low latency of 120 ms. The system described in this paper will contribute to the activation of audio telehearing services as it is possible to provide audio remote services in various places, such as express buses, trains, wide-area and intercity buses, public waiting rooms, and various application services.

This study examines the multidimensional impacts of solar power deployment in rural areas on local communities using a system dynamics approach. A regional model was developed for Jeollanam-do, South Korea, integrating population dynamics, economic activity, land use, and carb on emissions. The simulation results indicate that while large-scale solar expansion significantly reduces net carb on emissions and increases regional income (GRDP), it accelerates population decline by diminishing rural landscape attractiveness. Notably, agrophotovoltaic (agroPV) systems were found to provide the most balanced outcome, mitigating population loss while achieving moderate economic benefits and substantial carbon reduction. These findings suggest that integrating solar power with agricultural land conservation, such as through agroPV, is essential for the long-term sustainability of rural communities.

본 논문은 국내/외 대규모 정전의 발생을 검토하고 전력 계통 운영 대책 방안을 검토하였다. 해외 주요 정전은 계통의 복잡화, 설비 투자 부족, 재생에너지 증가, 송전선 과부하 등 다양한 원인으로 분석된다. 최근 발생한 스페인 대정전의 큰 원인은 재생에너지의 의존도의 증가와 전력망의 취약성이 결합하여 발생하였다. 유럽의 전력 계통 정전으로 사회적 혼란과 경제적 손실이 발생하였다. 특히, 스페인은 풍력과 태양광의 비중이 높아 재생에너지의 영향이 크다. 국내도 탄소 배출을 줄이기 위한 에너지 정책으로 재생에너지의 발전 비중을 확대하기위해 추진하고 있다. 본 논문은 정전에 영향을 미칠 수 있는 재생에너지에 운영 전략을 검토하였다. 이를 통해 국내 재생에너지의 확대 목표를 달성하면서 전력계통의 안정성과 신뢰도를 유지하기 위한 계통운영방안 수립에 기여하고자 한다.

This paper has been examined the occurrence of large-scale blackouts domestically and internationally and reviews operational countermeasures for the domestic power system. It was analyzed the major overseas blackouts as stemming from various causes, including increasing grid complexity, insufficient equipment investment, rising renewable energy adoption, and transmission line overloads. Recently, large-scale blackout in Spain has been considered to have resulted primarily from the combination of increased reliance on renewable energy and grid vulnerabilities. It has been caused significant social disruption and economic losses in the European power grid blackout. Particularly, Spain is highly sensitive to the impact of renewable energy, with a high proportion of wind and solar power. Domestically, energy policies has been aimed at reducing carbon emissions due to promoting an expansion in the generation share of renewable energy. This paper proposed that has been examined operational strategies for renewable energy that could impact power outages. It has been considered to contribute to establishing grid operation plans that maintain power system stability and reliability while achieving domestic renewable energy expansion targets.

최근, 국내 전력계통에서 정전사고가 증가되고 있다. 이에 따라 전력을 사용하는 산업과 주거에 경제적 손실과 불편이 초래되고 있다. 국내 전력계통의 정전은 순간전압강하와 설비 문제로서 상업용 시설과 도심지의 정 전과 이에 따른 설비 노후화, 전문 인력수급, 그리고 분리된 기관의 단일화 등의 사회적 이슈가 되고 있다. 순간전 압강하에 의해 수도권에 있는 놀이시설이 멈춰서고, 변전소 개폐기 설비운영의 미숙으로 인해 최대산단이 밀집되 어 있는 도심의 일부가 일정시간 동안 전력공급이 원활이 되지 않은 경우가 발생하였다. 이러한 이유로는 첫째, 변전소, 송배전망의 관리 투자의 소홀로 인한 전력설비의 노후화이다. 둘째, 전력망 건설 및 유지보수를 위한 인력 의 문제이다. 마지막으로, 전력망을 관리하는 한전의 분리로 인한 전력신뢰도 관리 및 경제성 관리에 의해 사고의 증가요인이 된다. 이는 국내 전력계통 정전사고가 앞으로도 계속해서 진행될 것이라 사료된다. 본 연구에서는 국 내 전력계통의 정전사고의 원인과 그 대책방법을 논의하도록 한다.

Recently, power outages have been increasing in the Korean power grid, causing economic losses and inconveniences to industries and residences. These outages have become significant social issues, especially those occurring in commercial facilities and downtown areas. The problems stem from momentary voltage drops and facility issues, including aging infrastructure, a lack of specialized personnel, and the fragmentation of management organizations. For example, momentary voltage drops have led to the shutdown of amusement facilities in metropolitan areas. Additionally, certain downtown areas, home to some of the largest industrial complexes, have experienced periodic disruptions in electricity supply due to immature substation switchgear operations. Several factors contribute to these issues. First, the aging of power facilities is due to insufficient investment in the management of substations and transmission and distribution networks. Second, there is a manpower shortage for the construction and maintenance of the power grid. Lastly, the separation of KEPCO, which manages the power grid, has led to increased accidents due to challenges in balancing power reliability and economic efficiency. It is anticipated that power outage incidents in the Korean power system will continue to occur in the future. This study will discuss the causes of these power outage incidents and propose countermeasures.

최근, 지구온난화와 산업화에 따라 전력수요에 따른 전력 에너지원의 전환에 대하여 국내외적으로 검토되 고 있다. 이에 본 논문은 에너지원의 전환에 의한 전력계통 전력요금과 신뢰도에 대해 조사하고, 전력계통의 특성 을 비교하였다. 그 방법으로, 첫째, 기존 전력 시스템의 안정성 가능성으로 인해 ESS 또는 스마트 그리드 기술 도 입의 필요성을 조사하였다. 둘째, 전력 요금은 신재생에너지 도입, 발전 연료비 변동, 정책 지원에 대해 검토하였 다. 특히, 독일의 에너지 전환 정책은 신재생에너지의 대중화와 요금 조정을 검토했습니다. 셋째, 국내 전력 운영 및 가격 정책을 시행하는 주요 국가와 비교하여 기술 도입 속도 및 규제 시스템의 차이를 검토했습니다. 본 연구 를 통해 국내의 전력운영 정책에 대해 토의를 통하여 국내의 효율적인 전력에너지의 전환 방안을 기대한다.

Recently, the conversion of electricity energy sources according to electricity demand has been reviewed at home and abroad due to global warming and industrialization. Therefore, this paper investigates the electricity cost and reliability of the power system due to the conversion of energy sources and compares the characteristics of the power system. First, the reliability of the existing power system was investigated for the need to introduce energy storage system or smart grid technology due to its reliability potential. Second, electricity prices were examined in relation to the introduction of renewable energy, changes in fuel costs for power generation, and policy support. In particular, Germany's energy transition policy examined the popularization of renewable energy and tariff adjustments. Third, we examined the differences in technology adoption rates and regulatory systems compared to major countries with domestic electricity operation and pricing policies. Through this study, we expect to discuss Korea's electricity operation policies and suggest ways to transition to efficient electricity energy in Korea.

The change in the power demand results in modification of frequency of interrelated power system amongst the dissimilar areas. The load frequency control can be attained by proper regulation of participating producing elements. The Area Control Error (ACE) has to be minimized for the frequency response enhancement and Integral Square Error (ISE) is generally taken as ACE. The aim of Load Frequency Control (LFC) is to diminish the Integral Square Error to Nil with constant variation of claim of dynamic energy so that the entire produced energy of the arrangement and load obligation correctly matches with every element. In this paper, results of multi area interconnected power system under Unilateral Contract are verified with the assistance of conventional controllers.