Improving the efficiency of power supply systems for agricultural enterprises and sparsely populated areas

Improving the efficiency of electricity supply in rural areas where agricultural enterprises and settlements are included will increase the overall efficiency of agriculture. This will be achieved by reducing production losses due to power outages and poor power quality. There will also be an improvement in the standard of living of rural residents, which contributes to more sustainable living and retention in rural areas. There is currently no universally accepted definition of efficiency in electricity supply systems, making it difficult to establish uniform methods to increase efficiency

THEORY OF THE QUESTION

The main reasons for the low efficiency of electricity supply in rural areas are related to the deterioration of rural electricity networks, which in some regions is 75% or more. However, there are also methodological problems hindering efficiency improvement. First of all, it is the lack of incentives for power grid companies and consumers to improve the system, as well as insufficient qualification of electrical engineering personnel at agricultural enterprises and power grid organisations [1]. These factors inhibit the introduction of new equipment and technologies, making it difficult to improve the situation.

The efficiency of power supplies is an indispensable characteristic when studying their performance characteristics. To accurately estimate the power rating, the measurement must be precise. It is recommended to use precision meters including wattmeters or power analysers to accurately measure input and output power for reliable calculation of its efficiency [2]. To ensure successful measurements, the cables must be connected correctly and the correct voltage must be measured. For AC measurements, an electronic AC source should be used to avoid any errors. In addition, electromagnetic interference from the device under test and electromagnetic noise in the surrounding environment must also be taken into account.

To get the most accurate estimate of efficiency, it is critical to measure the performance of your device over a range of temperatures and operating times. Temperature variations as well as

Агротехника и энергообеспечение. – 2023. – № 4 (41)                        67

duration are important elements to consider when evaluating overall efficiency [3]. Generally, the efficiency of a power supply is expressed as a percentage and can range from 60% to 95% depending on the type of power supply. High efficiency power supplies have efficiencies of 80% or higher, while standard power supplies have efficiencies between 60% and 75%. Knowing the typical efficiency of a power supply can help you choose the right power supply for your needs.

One of the main difficulties is the lack of an effective system for monitoring the failure of rural electricity networks and the condition of equipment, including transmission lines, as well as insufficiently developed methodologies for assessing the potential for utilising local power sources. This leads to unsuccessful projects and an outdated approach to the design of rural electricity networks, which reduces their reliability and quality of electricity supply. Problems are also associated with insufficient automation, control and regulation of rural power grids due to the focus on the development of industrial and urban grids. Addressing these problems requires a systematic approach and the development of a methodology to improve the efficiency of electricity supply in rural areas.

METHODS AND MATERIALS

In this study, a comprehensive approach was used, including the analysis of literature sources. Mathematical modelling methods were used to optimise the parameters of power grids. Comparative analyses of the efficiency of various technological solutions in the field of reactive power compensation and power supply monitoring were carried out.

RESULTS AND THEIR DISCUSSION

The quality of the power supply is an indispensable factor to consider with regard to energy consumption and operating costs. An inefficient power supply will undoubtedly lead to high energy bills, increased heat generation, and the possibility of system breakdowns. A highly efficient power supply saves energy and reduces operating costs, making it an ideal choice for both residential and commercial applications [4].

In addition, an inefficient power supply can adversely affect system performance by causing voltage fluctuations and instability. A high-efficiency power supply with stable power ensures that system components receive the power they need to operate efficiently. So, what is a typical power supply efficiency rating? Typical power supply efficiency depends on the type of power supply and its intended use. Standard power supplies have efficiencies between 60% and 75%, while high-efficiency power supplies have efficiencies of 80% or higher. Power supply efficiency is expressed as a percentage and measures the ratio of output power to input power.

To ensure safe and trouble-free operation of power supplies, the Environmental Protection Agency (EPA) and the Department of Energy (DOE) set strict performance standards that must be met before any product can be released to consumers. This ensures that all products meet basic energy efficiency standards. When it comes to choosing the best efficiency rating for a power supply, you need to consider your specific needs. If you are using a power supply for home or office use, an efficiency of 80% is more than enough to save energy and reduce operating costs [5].

On the other hand, if you require something with higher performance, such as servers or data centres, then opting for equipment with at least 90% efficiency or higher will ensure maximum performance and energy savings. When selecting a power supply, it is also important to consider other factors such as supply voltage, UL listed certification, and manufacturer reputation, as these factors can have a significant impact on the efficiency, safety, and reliability of the power supply.

Moreover, UL listed products are the gold standard for safety certification, whereas UL recognised products are usually only certified for one aspect such as flammability. In addition, opting for a modular design is advantageous as it reduces cable tangles and further minimises energy loss in powering your system [6]. A number of measures can be taken to reduce power losses during transmission from the power plant to the end users. For example, the proper selection of cross sections and materials of transmission lines, as well as determining the optimum number and capacity of transformers in substations. The use of reactive power compensation devices also helps to reduce losses.

In addition, electricity losses can be reduced by switching to higher voltages in the external and internal power networks of enterprises. In this case, it is worth considering technical and economic aspects, as higher voltages require more insulators and stronger supports. One of the effective methods is the inclusion of reserve power lines in operation. This reduces energy losses in the supply lines, especially if the backup line is used together with the main line. It is also important to minimise the number of transformations, as each transformation results in energy losses. When designing the power supply system, it is necessary to consider the load schedule and select the optimum number of transformers based on technical and economic calculations.

In order to reduce losses, it is also useful to switch off the power transformers during nonoperating periods, which avoids idle losses and increases the power factor. At the same time, it is important not to compromise the reliability of the power supply. Monitoring of electrical parameters is an integral part of ensuring stable operation of electrical installations and maintaining specified operating modes, as well as for detecting and eliminating unbalanced loads in electrical networks. These measurements are carried out when setting up automatic power regulators, short-circuit and overload protection systems, as well as to assess the efficiency of electricity utilisation [7].

Monitoring is carried out continuously using accurate measuring instruments installed on control desks and control panels. If necessary, periodic more accurate measurements are made. When selecting instrumentation, the characteristics of the equipment to be monitored, such as voltage, frequency and overload capacity, must be taken into account and appropriate instrumentation used for monitoring. Many industrial plants have significant reactive power requirements for normal equipment operation. Reactive power creates additional power losses and requires increased conductor cross sections and transformer capacity. However, it is possible to compensate for reactive power, thus reducing or completely eliminating its impact on the system. This is achieved by placing reactive power generators at different points in the power system, which provides more efficient use of electricity and reduces losses.

In order to achieve the goals of import substitution in the field of providing power supply systems with domestic developments, it is necessary to carry out the following activities:

• 1.    to study and adapt the best world experience in improving the efficiency of power supply systems for consumers.

• 2.    Analyse and systematise the experience of rural electrification and power supply of rural consumers.

• 3.    Develop methods and equipment to improve the efficiency of rural electricity supply systems.

• 4.    To create production of equipment for automation of rural electrical networks.

• 5.    To develop and introduce equipment for monitoring systems of power supply reliability and quality of supplied electricity in rural areas.

• 6.    To develop equipment for educational purposes and organise its production.

• 7.    To develop and promote standards, recommendations, guidelines and bills for the use of the developed tools to improve the efficiency of electricity supply systems in rural areas.

• 8.    Develop techniques for evaluating renewable energy opportunities and create automation equipment for small-scale power generation.

• 9.    Conduct additional training (professional retraining and advanced training) for engineers, electrical and thermal engineering personnel of enterprises, energy companies, equipment manufacturers and other specialists in this field.

CONCLUSIONS

The development of these methods for improving consumer power supply systems will lead to a number of products and solutions:

• 1.    Recommendations, instructions and rules for assessing the efficiency of rural electricity supply and methods for its improvement.

• 2.    Methods, algorithms and equipment for sectionalisation and redundancy of electric networks, implementation of "smart" electric networks.

• 3.    Monitoring systems for assessing the reliability of power supply and the quality of supplied electricity.

• 4.    Monitoring systems for evaluation of technical condition of power supply elements.

• 5.    Methodologies for assessing opportunities for utilisation of small and renewable energy sources.

• 6.    Methods and equipment for joint utilisation of traditional power grids and small-scale generation facilities.

• 7.    Techniques and equipment to improve the safety of rural power grid operation, including prevention of unauthorised connections of generating facilities.

• 8.    Systems for technical connections to power grids, including methods for forecasting the volume of technical connections and justification of investment programmes for the development of power grids.

• 9.    Recommendations and amendments to the rules in the field of energy sales activities aimed at improving subscriber accounting and equipping energy sales companies.

• 10.    Technical and economic mechanisms to encourage consumers and power grid organisations to improve the efficiency of electricity supply systems.

The solutions presented above will significantly improve the reliability of electricity supply to the districts, ensure high quality of electricity supply, optimise the processes of technological connections to power grids and promote the use of small-scale energy facilities.