Distributed Generation & Alternative Energy Journal

Energy Storage Configuration Evaluation Method for Renewable Energy Consumption Based on Power Grid Development Planning and Resource Output Forecast Analysis

Guozhen Ma, Shiyao Hu, Yunjia Wang, Ning Pang, Junyi Yu — Wed, 19 Feb 2025 00:00:00 +0100

In recent years, the rapid development of new energy sectors, particularly photovoltaic and wind power, has introduced significant challenges stemming from their inherent randomness and volatility. This paper presents a systematic approach for effective evaluation of energy storage configurations. The study begins by examining the anticipated evolution of the power grid in alignment with China’s energy policies, focusing on the annual growth rates of wind power, photovoltaic systems, and energy demand. This analysis establishes a foundation for planning energy storage installations. Next, a forecasting method is employed to predict the output of both photovoltaic and wind energy resources. Building on this, a novel control strategy is proposed for integrating renewable energy sources into the grid, facilitating the determination of optimal energy contributions to ensure a stable power supply. A comprehensive energy storage configuration model is then developed, accompanied by a multi-faceted analytical framework to assess energy storage from perspectives such as environmental impact, economic feasibility, operational flexibility, and technological advancement. Ultimately, this research provides a scientific assessment of energy storage configurations, grounded in grid development projections and resource output forecasts.

Determining the Correct Electrical Resistance of Conductors in Power Systems Analysis

Massimo Mitolo — Wed, 19 Feb 2025 00:00:00 +0100

The electrical resistance of a conductor varies with its material (e.g., copper or aluminum) and operating temperature.

This paper discusses the importance of determining conductor resistance at the appropriate temperature for voltage drop calculations, short-circuit current assessments, and ground-fault current evaluations in power system design. To normalize conductors based on their electrical characteristics, standards specify nominal cross-sectional areas uniquely associated with specific resistance values per unit length at 20 $^{\circ}$

C. These resistance values, considering the metal’s resistivity, can be reliably measured, eliminating the need for potentially unreliable physical measurements, especially in stranded wires.

The paper highlights the need for conservative approaches in voltage drop calculations by considering maximum operating temperatures of insulation materials and outlines the methodologies for accurately determining the resistance for maximum and minimum prospective short-circuit currents calculations. Additionally, it addresses the significance of proper ground-fault currents calculations to ensure speedy protective device operation, thereby enhancing system safety and reliability. The principles and standards herein discussed are applicable across various global power systems, underscoring the universal importance of standardized practices in electrical resistance calculations.

Research on Optimization of Intelligent Data Driven Monitoring and Status Evaluation Mechanism for Distribution Network and Distributed Resources

Wed, 19 Feb 2025 00:00:00 +0100

With the rapid development of smart grid technology, in-depth research on intelligent data-driven monitoring and status evaluation mechanisms for distribution networks and distributed resources has become a key factor in improving the operational efficiency, safety, and reliability of power systems. This article aims to achieve precise management and optimized scheduling of distribution networks and distributed resources by establishing an efficient and intelligent monitoring and evaluation system. We have collected over 10TB of data from multiple smart distribution network pilot projects, including real-time operational data, equipment status information, user electricity usage behavior, and more. By adopting advanced data preprocessing techniques, including data cleaning, integration, and transformation, low-quality and incomplete data are effectively eliminated, ensuring the integrity and quality of the dataset. Subsequently, the processed data is deeply mined and analyzed using a distributed computing framework. The prediction model proposed in this article provides high-precision predictions of key indicators, such as load changes and power generation within the distribution network, with an average prediction accuracy of over 95%. By utilizing clustering analysis and association rule mining techniques, potential fault points within the distribution network were successfully identified, furnishing scientific decision-making support for operations and maintenance personnel. In the realm of distributed resource state assessment, a novel state assessment model grounded in multi-source data fusion has been introduced. This model comprehensively considers the operational characteristics of distributed energy, environmental factors, and grid constraints and can comprehensively and accurately evaluate the status of distributed resources. The experiment found that this system significantly improved the utilization of distributed resources and the overall operational efficiency of the power grid, with an average increase of over 10%.

Research on Optimization of Distribution Network Connection Mode Based on Graph Neural Network and Genetic Algorithm

Guo Chen, Wang Hui, Yan Huan, Li Bingchen, Zhou Xingxing — Wed, 19 Feb 2025 00:00:00 +0100

With the deep integration of electric power and information technology systems, the distribution system shows the trend of increasingly complex structures and increasing external risk factors. This leads to more diversified types of faults in the distribution network, so it is crucial to optimize its topology. In this paper, we first compare the main connection modes of high-voltage and medium-voltage distribution networks in China, and combine them with the specific needs of Shaanxi Power Grid to propose a differentiated flexible network model and its scope of application. Using Graph Neural Network and Genetic Algorithm, an innovative optimization method of distribution network connection is proposed to support the typical network structure of the new distribution network. Analysis of examples shows that the proposed algorithm can improve the original network’s network loss and voltage deviation by 32.8% and 37.3%, respectively, and the improvement effect is better than that of the traditional genetic algorithm. At the same time, considering the different stages of distribution network development and the uncertainties that may be faced, this paper also explores the flexible transition scheme of each typical network structure to ensure a smooth transition to a more efficient, green and intelligent distribution network model without affecting the reliability of the existing power supply.

Research on Overvoltage Monitoring Technology for Distributed New Energy Intelligent Stations

Zhidu Huang, Longfei Zhang, Wei Huang, Shan Li, Yajuan Chen — Wed, 19 Feb 2025 00:00:00 +0100

Distributed renewable energy sources such as wind, solar, and small hydropower of the new distribution network are mainly connected to the grid through distribution lines, which are susceptible to lightning overvoltage. Therefore, this paper conducts a lightning risk assessment of the active distribution network system, including the photovoltaic (PV) side and the line-side. The study analyzes the effectiveness of two lightning protection measures: strengthening insulation and installing lightning arresters in the new distribution network. Strengthening insulation involves enhancing the first three towers and all line towers. However, the results show that both methods cannot effectively reduce the lightning failure rate on the PV-side and may even lead to adverse effects. Additionally, the analysis of in stalling lightning arresters reveals that installing them on the first-level towers of the distribution line can significantly reduce the impact of lightning on both the line and PV-sides. In particular, installing lightning arresters simultaneously on the first three towers closest to the PV-side can drastically reduce the overall lightning trip rate on the line-side.