Abstract
Сontent
- Introduction
- 1. The relevance of the topic
- 2. The purpose and objectives of the study
- 3. Problems of autonomous power supply systems
- 4. Consumption of electric energy independent power system
- 5. Control algorithms modes VDES
- Conclusions
- References
Introduction
More than 20 million. Living in the outermost regions, outside the coverage area of centralized power, are experiencing an acute shortage of electricity. The main problems of energy supply, isolated from the power supply systems, consumers are further fuel for transport local diesel power plants (DPP) and its dependence on supplies. IN the most inaccessible areas, these problems are compounded by a ladder transport schemes and limited seasonal periods of delivery.
Sources of low power used for offline supply are usually low feasibility indicators - specific fuel consumption of 500-600 g of fuel equivalent / kWh and 300 350 kg of standard fuel / Gcal. Diesel power stations and boilers are often in poor condition. The rise in prices for diesel fuel helps increase in the cost of electricity generated by diesel power.
One of the promising directions of development of the autonomous power supply, allowing a large extent solve the problems DES is a renewable energy, particularly wind power.
Many regions of the autonomous power of Siberia and the Far East Far North have high wind potential, so an important direction in the development of decentralized energy supply It is the use of wind-diesel plants (VDES).
The use of renewable energy sources in the autonomous energy systems to reduce fuel component in the cost of electricity generated, which greatly increases their technical and economic efficiency.
1. The relevance of the topic
Currently in the world there are different variants of hybrid plants based VDES, but how to optimize the structure and system parameters require further research.
Research in the field of autonomous power supply Consumer-based VDES the last 10 years dedicated to a number of scientific research of Russian scientists: PP Bezrukov, V.G.Nikolaev, MA Surkov, VR Kiushkina, AA Averin, AV Bobrov VV Vessart, AV Chebodayev, AN Doroshin, NM Greenhouses, RV Pugachev, and foreign authors: Tomilson Andrew, Memorial University of Newfoundland; Jeffries William Q. Ph.D. University of Massachusetts Amherst; Akarin Suwannarat, Institute of Energy Technology, Aalborg University, Denmark. This paper considers the question: mathematical modeling of operation modes station algorithms VDES, assessment of the economic efficiency of the system, but there are a number problems in this area, which is not fully understood.
Performance of combined power system is largely dependent from power and performance of its member units and their modes. An important task is the coordination modes Components included in the wind-diesel power [1].
2. The purpose and objectives of the study
Objective. Improving the energy efficiency of autonomous systems power on the basis of rational choice by VDES main generating equipment and optimization of its operating modes.
To achieve this goal in the thesis identified and solved the following research objectives:
– A comparative analysis of options for building a wind-diesel power plants, the most promising scheme for constructing VDES for independent power supply;
– The analysis of existing methods of calculating capacity generated by the wind farm, the technique that allows more accurate calculate the energy generated by the wind farm;
– analysis methods for the calculation of electrical loads isolated networks graphing electrical loads Autonomous consumer has developed a universal method of calculation load consumption;
– an algorithm for the effective management of operating modes VDES ensuring maximum use of the wind potential, which allows to reduce fuel consumption and increase the service life equipment;
– developed a method of evaluating the economic efficiency autonomous wind-diesel power stations to allow for rational choice of the basic generating equipment and its modes operation.
Research methods. When the thesis used: methods of analysis and synthesis of the data presented in the scientific literature, probabilistic and statistical methods of data analysis; methods of mathematical modeling, simulation, experimental studies [4].
Scientific novelty. As a result of investigations, the following new scientific results:
– The rational options for the structure of an autonomous system power supply on the basis VDES, including controllable ballast allowing the load to optimize the operating conditions of the main power equipment;
– developed a mathematical model of wind-diesel system electricity, taking into account the real changes in the power load, the ratio of installed capacity of wind and diesel component generating equipment, the actual wind conditions of the area power supply;
– built energy-efficient modes of control algorithms power power plants VDES allowing: maximum exploit the potential of wind; to provide the most economical mode DES works; increase the service life of the equipment.
The practical value of the work:
– proposed generic method of calculating consumption and load wind power capacity for the short and long term Planning modes VDES;
– developed a method of evaluating the economic efficiency autonomous wind-diesel power supply system;
– developed recommendations to improve energy efficiency autonomous power supply systems by selecting the management structure VDES and modes of operation of the power equipment;
– created software package for research and formation rational modes VDES and analysis of its energy balances.
The reliability of the results of the thesis. The findings of the thesis research results are based on a comprehensive analysis performed earlier research work in this field of research. During the used analytical and experimental methods of validation results.
3. Problems of autonomous power supply systems
The basis of small-scale energy currently account for up to 50 thousands of different, mostly diesel power. practical DES operation experience shows that fuel costs are determinants of the cost of electricity generated by DES (Figure 1). Therefore, minimizing fuel consumption during operation is DES the most important strategic task, determined by economic plant efficiency.
Figure 1. Figure the cost of production and transport of electricity:
for DES "Sakhaenergo".
(animation: 5 frames, 6 cycles of repetition, 166 kB)
Among the most important trends in the development of power supply systems isolated consumers, providing improvement of quality and cost-efficiency of electricity and heat by reducing fuel consumption, along with the reconstruction, is the use of renewable energy sources. For zones decentralized Emergency power supply, or combined interest hybrid plant combining wind farm with diesel power plants that cover the lack of generated energy windless periods.
Small wind turbines (windmills) (up to 100 kW) It is widely used for autonomous power supply of consumers, as they structurally simple and essential wind energy is available in many autonomous power supply areas [9].
The wind speed and the load consumption are random values, which in combination with comparable capacity main energy equipment requires coordination in real time modes of production and consumption. partially matching problem can be solved by using a power system buffer energy storage, which is used as batteries (AB).
Improving the energy efficiency of diesel power plants using wind energy plant rather difficult task. Review from EU Structural the most common schemes VDES possible to determine promising system (Figure 2), which provides a rational electricity consumers in a wide range of facilities and wind conditions.
Figure 2. Promising a block diagram of the construction of VDES Legend: G - generator; RB - ballast control; AT - rectifier; BN - block ballasts; AB - Rechargeable battery; And - an inverter; H - the payload; DD - diesel engine; SG - synchronous generator; NL - busbar; RA - a regulator Battery battery.
The multicomponent structure of power requires the development of specialized control algorithms, which should provide uninterrupted supply of electricity consumers in the conditions changing external factors that have a significant impact on operation of the main generating equipment (load and wind speed). In addition, we need a rational choice of methods and the type of capacity power units, as well as the methods of calculation of feasibility characteristics of the project.
4. Consumption of electric energy independent power system
For practical use of renewable energy installations in the autonomous power complexes, as well as the choice main power equipment necessary to solve a number of technical problems considered in the second chapter, the most important of which is the harmonization of the energy production and consumption in terms time stochastic processes, changes in the electrical load the consumer and the power of the primary energy source, wind. Relying on regulations and type of load, designed a universal method of determining the load consumption decentralized user (Figure 3).
Figure 3. A block diagram of the calculation of the forecast electricity consumption modes energy independent power system
The main factors that determine the power consumption modes locality, provides electricity from autonomous power system are the number of inhabitants and types of electrical loads, which are generally divided into: - Household - load consumption population (housing, dormitories); - Social - load consumption of social objects destination (shops, schools, theaters, etc.) - Manufacturing - load consumption enterprises.
Significant impact on the modes of energy consumption may have geographical, climatic and technical characteristics of the particular settlement: the average annual temperature, the amount of winter and summer days, the level of comfort municipal domestic sphere, etc.
Determining load consumption based on the use of standard charts elektiricheskih loads.
The analysis of the actual data on the annual consumption electric power autonomous energy systems has shown that combining domestic and social burden it with reference to the number population adopted in the regulations, provides low the accuracy of the forecast.
Fig. 4 are averaged over 2006 - 2010. depending Annual consumption of electricity, built on According to the actual power consumption 79 autonomous energy System of the Republic of Sakha (Yakutia) with population served the population from 20 to 859 people.
Figure 4. The actual dependence of the annual electricity consumption of Population autonomous power supply systems of the Republic of Sakha (Yakutia): a) domestic load b) social burden.
4. Control algorithms modes VDES
The logic of the proposed algorithm based on two basic principles: maximum utility the use of energy generated by wind farm, and minimizing the number of hours DEL. For practical implementation of the control algorithm is required continuous monitoring of energy stored in the buffer storage and the current values ??generated, consumed and of stored capacity. In addition, DES must be implemented by three degrees of automation, Provides remote automatic start and stop diesel motor. Intelligent control system (CS) provides VDES continuous distribution of energy flows in a closed energy system depending on its current state. From a management perspective, duty station determined by the ratio of current values power generated by the wind turbine and the load. There are two basic modes: [4].
Figure 5. The control algorithm modes VDES
