Alternative structures for rural distribution networks

With the modernization and intelligent development of agriculture, the energy demand in rural areas continues to increase, which leads to an increased operational burden on the existing rural distribution network. Integrated energy stations (IESs), in rural areas, use renewable energy sources such as biogas, wind power, and photovoltaic as energy inputs, which can fully improve energy efficiency and help reduce the operating load and peak valley difference of rural distribution networks. In this paper, a multistage planning model is proposed for rural distribution networks with IESs based on the robust optimization method. Firstly, a rural distribution network operation framework with IESs is proposed, and a mathematical model of rural IESs is built based on the energy hub (EH). Then, the multistage robust planning model of rural distribution net-works with IESs is developed and typical scenarios of stochastic source and load are generated based on improved k-means. An iterative solution method for a two-stage robust optimization method is proposed based on the nested column constraint generation (NC&CG) algorithm. Finally, the effectiveness of the presented model and solution approach is assessed through case studies on a modified IEEE 33-node distribution network and a real 152-node distribution network.

The article presents calculations the additional electric loss in the case of three-phase voltage system unbalance in the real rural electrical distribution networks (0.38 kV). Measurements were carried out at substations that receive power from distribution substation “Petropavlovsk”. Measurements were carried out using a certified device “Resource-UF2M”. Also presented are graphs of changes in currents/voltages of the negative-sequence and zero-sequence, electric loss and other parameters. The results of the economic assessment of electricity losses are presented. As a result, the proposed method for reducing the power loss factor, that can reduce the losses of electricity.

Distribution network operators typically produce a report of network performance for all networks as a whole, by not segregating it in a different area; urban and rural networks. Although the report is sufficient, it does not represent the actual performance of each urban and rural networks. Therefore, this paper presents the configurations, parameters, and component rating for medium voltage urban and rural distribution networks. Both networks are assessed with analytical and Monte-Carlo simulation techniques. Each assessment was correlated with Energy Regulator requirements for accurate results. Urban area has better network performance due to sophisticated network automation and network configuration with n-1 or n-2 security compared to the rural area.

In recent years, extreme cold disasters have occurred frequently worldwide. The security of rural distribution network is threatened. The current research on enhancing the resilience of distribution network fails to consider the changes in the operating characteristics and efficiency of equipment under extreme cold disasters. To address this, this paper uses hydrogen‐integrated energy systems (HIES) to enhance the resilience of rural distribution network under extreme cold disasters. The method considers ensuring the power supply of rural lifeline load. A power support capability evaluation model of HIES is established. The model takes into account the impacts of low‐temperature conditions on the operational characteristics and efficiency of hydrogen energy equipment and photovoltaic equipment. An energy demand model considering livelihood security lifeline load, public service lifeline load and cultivation‐breeding lifeline load under extreme cold disasters is established. A rural distribution network resilience enhancement model is developed. Its goal is to maximise the restored energy demand of lifeline load. The example shows that the lifeline load recovery rate is increased by 38.98% and the primary load recovery rate is increased by 5.44% using the method proposed in this paper.

In rural distribution networks with widely dispersed loads, characterized by the utilization of long overhead lines, voltage profiles with big variations appear along the line due to the significant variations of the load between peak hours and valley hours. This paper describes the problems that the integration of distributed generation based on renewable resources could generate in that scenario, and presents solutions that are commonly used to mitigate these problems and proposes new solutions to solve them. The integration of distributed generation (DG) based on renewable resources in these networks increases the variability of the voltage, and in some cases the power flow of the network also can be bidirectional. Usually this integration of distributed generation is limited by the network operator limiting the maximum voltage variation produced by the distributed generation in the point of common coupling (PCC). In this paper different traditional methods for voltage control are described and analyzed for a widely dispersed rural network scenario. The impact of the DG in these methods of voltage control and the advantages of power electronics in this new scenario are exposed. Power Electronic devices applied to these distribution networks allow more efficient management of the network increasing the integration of distributed generation maintaining the security levels.

In recent years, the voltage quality in rural areas has aroused strong concern from the Stat Grid Corporation of China. This paper firstly analyze the over-voltage issues in the rural distribution networks from HUNAN province, and then proposes an output voltage control scheme of the Electric Spring (ES) to alleviate severe over-voltage problem in rural areas. The control objective of the ES is to regulate its output voltage where the load is directly integrated with, it maintains the voltage equals to its nominal value for every incorporated load. An operation mode selector is proposed for the ES control loop to automatically select inductive mode, capacitive mode or terminate the operation depending on the load voltage condition and load type. The control scheme is tested in a rural distribution network based on realistic data using Matlab/Simulink simulation. The effectiveness of voltage regulation is compared with the ES using input voltage control scheme. Simulation results show that under the common voltage condition in rural distribution networks from China, the ES with output voltage control scheme provides better voltage regulation for every customers along the distribution line, and it also reduced the voltage deviation between the distribution transformer and the end user due to the over length power supply distance.

The purpose of this paper is to establish algorithms in the design of rural low-voltage (LV) distribution networks. Planning of rural LV distribution networks involves the optimal design of radial configuration and location of MV/LV substations considering cost functions. In this work both goals are considered by taking into account different conductors, voltage drop constraints, power losses in lines and deterministic loads. The algorithms developed in this paper are based on dynamic programming; and were implemented on large-scale rural LV distribution networks, but they could also be used for other network optimization.

The rapid development of photovoltaics (PVs) and load caused a significant increase in peak loads and peak‐valley differences in rural distribution networks, which require load peak shifting and line upgrading. Large peak‐valley differences also bring challenges on the safe operation of the utility power grid. Considering the integration of a high proportion of PVs, this study establishes a bilevel comprehensive configuration model for energy storage allocation and line upgrading in distribution networks, which can reduce peak loads and peak‐valley differences. In the upper level, a minimum annual planning cost is obtained by developing the installation capacity of centralised energy storage in transformer stations, the installation location and capacity of decentralised energy storage on lines and a scheme of line upgrading. In the lower level, the minimum total annual operation cost of the distribution network is obtained by developing an optimal scheduling for the centralised energy storage in transformer stations and decentralised energy storage on lines. Simulation results show that compared with the conventional energy storage planning strategy, the configuration investment can be reduced by 467.66 million yuan at least with the proposed strategy.

Against the backdrop of imbalanced urban–rural spatial structures and energy resource allocation, along with the continuous increase in distributed photovoltaic (PV) penetration rate, achieving orderly PV expansion and optimal energy storage (ES) configuration has become an urgent requirement for urban–rural distribution network planning. Existing research generally overlooks regional differences between urban and rural areas, making multiregional collaborative optimization difficult to achieve. Therefore, this paper proposes a distributed collaborative planning model for PV and ES (PV–ES) in multiregional urban–rural distribution networks based on the analytical target cascading (ATC) algorithm. By establishing a collaborative planning model that accounts for urban–rural differences, system decoupling is achieved through decomposition modeling and distributed parallel solution is accomplished using the ATC algorithm. Case validation demonstrates that the proposed model can coordinately optimize PV–ES configuration across multiple urban–rural regions, simultaneously enhancing system economics and significantly reducing impact on the upper‐level grid.The study further proposes a three‐level planning implementation pathway of “municipal–county–township” transmission, providing systematic technical methods and planning support for promoting the integration of urban–rural energy infrastructure.

Georeferenced rural distribution network model considering scalable growth of users in rural areas

With continuous improvement of the retention rate of household electrical appliances, the peak valley difference of power distribution network, especially the rural distribution network is expanding. A reasonable management method of the demand side is needed to realize load shifting and economic operation of distribution network. At present, the cost of energy storage(ES) equipment is decreasing, which provides a new idea for the optimization of distribution network operation. This paper studied the charge/discharge model and strategy of ES, and constructed a multi-period optimal operation strategy model of distribution network with ES. Sparse coding automatic differentiation technology was applied to reduce coding workload, and constraint reduction of ES was proposed to reduce differential calculation, which enhanced the feasibility and efficiency of the model solving. Finally, the simulation results of an actual distribution network with ES demonstrated the accuracy of the proposed model, the efficiency of the proposed algorithm and the feasibility of the proposed solving method.

Usually, rural areas can be electrified via three-phase distribution transformers with relatively large capacities. In such areas, low voltage lines are used for long distances, which cause power losses and voltage drop for different types of consumers. Reducing losses and improving voltage profiles in rural distribution networks are significant challenges for electricity distribution companies. However different solutions were proposed in the literature to overcome these challenges, most of them face difficulties when applied in the conventional distribution network. To address the above issues, an applicable solution is proposed in this paper by installing a number of small-capacity distribution transformers instead of every single large-capacity transformer in rural areas. The proposed approach is implemented in the branch network of Al-Hoqool village, which belongs to the Nineveh distribution network. The network has been inspected on-site, drawn, and analyzed using the electrical systems analysis program (ETAP). The analysis showed that using the single-phase pole-mounted transformers can improve the voltage in the network’s end by 29% and enhance the voltage profile for all consumers. The analysis has also demonstrated that the modification can reduce the total power losses by 78% compared to the existing network. Concerning the economic aspect, the payback period for the proposed network is assigned to be 20 months.

In order to further guide the construction, transformation, operation and maintenance and management of urban and rural distribution networks, and to comprehensively promote the improvement of power supply reliability indicators, lay a solid foundation. Improve the quality of equipment, improve the level of power outage management and control, and increase the application of non-interruption operations. According to the current situation of power supply reliability of a domestic power supply bureau in the past three years, according to the number of outages, outage time, and outage scope, research is in line with the reliability assessment method of the region, and proposed Suggestions for improving the reliability of power supply in this area.

The power supply systems of the agro-industrial complex are full with electrical equipment that requires a supply voltage corresponding to GOST for normal operation. Operating modes caused by the nonlinear load have a negative impact on the operation of power electrical equipment, relay protections, automation elements and switching devices. Additional power losses associated with higher current harmonics appear during operation of all types of electric motors and in electrical installations in conditions of non-sinusoidal voltage. The technical parameters of the operation of electrical equipment, as well as the quantitative and qualitative properties of the products largely depend on the quality of electrical energy in the electrical supply systems of enterprises of the agro-industrial sector. The correct use of methods and means of improving the quality of electric energy will allow us to calculate more accurately the economic damage from non-sinusoidal and asymmetric operating modes. These conditions should be taken into account when designing and operating power supply systems. The need to determine the damage arises during the development and adjustment of standard documents on the quality of electricity when justifying the limit values of the quality indicators. (Research purpose) The research purpose is studying the influence of higher harmonics on the operating modes of electrical equipment in rural distribution networks. (Materials and methods) The article presents the main sources of voltage distortion, calculations on power losses in distribution grids of agricultural consumers. (Results and discussion) The article presents the results of measuring the non-sinusoidal voltage in the distribution grids of agricultural enterprises. The coefficients of the harmonic components in the voltage harmonics spectrum is higher than it should be. (Conclusions) The losses associated with the low quality of the supply voltage caused by electromagnetic and technological components.

The increasing global integration of photovoltaic (PV) systems, vital for sustainable development, presents significant operational challenges in rural distribution networks. These feeders, particularly those in Kenya with high resistance-to-reactance (R/X) ratios, are prone to reverse power flow (RPF) and voltage instability, with generic smart inverter controls often proving ineffective due to insufficient voltage rise. This paper addresses this critical gap by developing and validating an adaptive, coordinated smart inverter control algorithm. Employing both Volt-VAR for reactive power support and Active Power Curtailment (APC), the strategy dynamically aligns PV output with real-time local load demand using quasi-static time-series simulations in OpenDSS for a representative Murang'a 11kV rural feeder in Kenya. This grid compliance was achieved at a quantified cost of approximately 1,500 kWh of curtailed renewable energy per day during the dry season. Critically, a comparative seasonal analysis was performed by repeating the simulations under rainy season (long rains) conditions, characterized by significantly reduced and variable solar irradiance. The rainy season results confirmed the absence of reverse power flow due to the naturally lower PV generation, which remained below local load demand throughout the day. This seasonal comparison validates that RPF is predominantly a dry-season phenomenon in this context and that the proposed adaptive control strategy is both critically necessary during high-irradiance periods and benignly non-intrusive during low-irradiance seasons. The study validates a practical methodology for high-penetration PV integration in challenging rural grids, emphasizing the necessity of feeder-specific, seasonally-informed control strategies to balance grid safety with renewable energy yield.