Выбор источников генерации для использования в микросетях на основе ВИЭ

Анотація

UDC 644 112

SELECTION OF GENERATIONSOURCESINres-BASEDMICROGRIDS

V. Kharchenko, V. Gusarov

Russian Institute for Electrification of Agriculture, Moscow, Russia

V. Adomavicius, J. Valickas

Kaunas University of Technology, Lithuania

Power supply facilities of Agriculture has some specific features: the dispersion of consumers, small unit power, the greater length of the electrical, thermal and gas networks, the presence of large areas, often sparsely populated, where agricultural production is carried out, but the centralized electricity and heat no. Ensuring a reliable supply of these areas is of paramount importance, the solution of which depends largely on the success of the task of ensuring the Russian Federation's food independence and rejection of food imports.

The reliability of energy networks, to minimize the loss of energy in them and the high economic efficiency of these networks play a significant role. Of great importance for the solution of the problem of sustainable energy supply is the use of microgrids farmers, formed mainly on the basis of renewable energy sources (RES) - a modern form of realization of the concept of distributed energy.

These systems were widely used in world practice and, in our opinion, are the prospects for further expansion of the scale. Creating scientific and methodological basis for the organization mikrosetevyh power systems in practice seems to be one of the most effective ways to promote the implementation in practice of this new innovative approach. The main provisions and principles of construction of microgrids were worked out earlier [1,2].

The purpose of research - study of generation sources to be used in microgrids based on renewable energy.

Materials and methods of research. The most promising for the construction of microgrids are rural areas, where access to renewable energy sources are less limited in comparison with the urban terrain, and where, as a rule, there are other local energy resources.

Configuration microgrids primarily determined by factors such as the composition and consumer Categorization; availability of consumer requiring uninterrupted power supply; the potential of different types of renewable energy sources on the territory of microgrids, particularly in places where objects of consumers.

The method of superposition graphs consumption and energy production in different formulations generation sources is a combination thereof, which fully provide coverage of all consumers loads with minimal storage capacity and redundancy and, naturally, with minimal capital and operating costs.

When micro-network operates in parallel with the power network, the need for accumulation of energy and the reservation can be minimized. At the same time work with the network can be arranged in several coordinated schemes: in the first case, to cover peak loads micro-network receives electricity from the network, and in relation to it is a regular customer; in the latter case the exchange of energy with the network is carried out in two directions, i.e. micro-network covers its deficit selection of energy from the network, and transmits electricity to the network in the presence of excess capacity. The bulk of the electricity produced and consumed at the same time stay in microgrids, so the last connection to the network of a large influence on it will not.

Of great importance for the effective functioning of microgrids has a well-organized management system, which is to perform the following functions: to support offline capacity balance; commuting generators and energy storage; control power regulated energy sources; to maintain voltage stability and frequency microgrids; ensure the collection of information necessary for consumers 'intelligent' load management, etc.

Clean autonomous micro-network it is advisable to create a connection in case of failure to a centralized network in regions with large renewable energy resources. The power of energy storage should be calculated taking into account the likely duration of time intervals without wind and solar radiation. But the ability to organize the work of microgrids in parallel with the central network will result in a significant benefit as reduce the level of capital expenditures and operating costs. Thus, the development of projects to create microgrids in a given area is supposed to solving problems at two levels: a) a first level includes consideration of issues relating to microgrids as a whole (the highest level), b) a second level includes consideration of issues relating to the selection of elements microgrids.

Solving problems on the first level. We consider such questions as:

1. Develop a concept microgrids, including consumers layout, circuit generators accommodation, storage and back-up power sources.

2. Determination of categorization electricity consumers, their consumption (daily, seasonal, annual), the degree of the need to ensure uninterrupted power supply, and impact assessment in the case of power modes of energy resource.

3. Evaluation of the potential of renewable energy at various points in the territory falling within the scope of microgrids, including in the area of consumer dislocation.

4. Development of the concept of generation sources of accommodation, their type, the kind used renewable resource.

5. The development of microgrids possible modes of operation with the condition of reliable power supply of consumers.

6. Assessment of the possibility of the development of microgrids in terms of the inclusion of new consumers and new sources of generation. it's necessary take into account that part of microgrids energy consumers at the same time can be and its producers operate their generators and / or energy storage. Micro-network integration of wind plants (WPP), solar stations (SES) and other sources of generation from renewable energy sources are much less red tape than attaching them to the centralized networks.

7. Evaluation of acceptable forms of ownership microgrids and its organizational structure (to consider the fact that to own and operate its microgrids are the owners of homes, businesses, ZAO, municipalities, etc.). In carrying out this work, it is important to take into account what consumers are scheduled for inclusion in the microgrids (existing or created) and how they will operate as part of microgrids (in microgrids input energy is mostly used by local consumers, which reduces the losses associated with the transmission of and power distribution grid.)

8. Evaluation of the presence in the vicinity of the power system network service area, and the possibility of technological connection to it.

9. Review of the reliability of power supply to consumers in microgrids (electricity supply reliability in emergency situations of various kinds within microgrids provide substantially easier than in large-scale energy systems; energy consumers in microgrids can participate in the process of balancing power by adjusting their loads, generating, accumulating and giving electricity micro-network).

10. Consideration of the economy microgrids and tariffs for energy supplied, as well as the payback period microgrids.

11. Ensuring the optimal choice of the control system and its implementation of microgrids.

When the micro-network is connected to the power grid network, significantly reduced requirements for storage and backup. In this embodiment, the micro-network works in parallel with the network, but most of the energy and produced, and consumed within microgrids. energy exchange flow is carried out in case of a transmission network in excess energy produced in microgrids, or to draw energy from the network to cover peak loads.

Solving problems on the second level. At this level, we deal with the choice of microgrids elements: the type and power of the energy generators, storage systems, construction of power transmission interface devices from generators in micro-network and a number of other issues related to micro-network components.

The results of research. The correct choice of elements microgrids represented an important stage in the formation of micro-network in a given area from the point of view of ensuring the reliability of its operation, the payback period, cost of produced and supplied energy resource.

For all consumers are made loads of graphs (daily, seasonal, monthly, yearly) and for generators - graphics generation based on renewable energy potential in their locations (the place to put them selected to provide maximum power).

Applying the method of superposition consumption charts and graphs of power generation for the different compositions generation sources, determined the optimal combination of both. At the same time maximize the coverage provided loads of all consumers with a minimum capacity backup and storage tanks and, of course, with minimal capital and operating costs.

If the possibility of parallel operation microgrids grid network, and the need for accumulation reservation can be minimized.

Choosing Effective consumer power supply options combined in a micro-network, it is a difficult problem of systemic analysis, as power systems differ in many ways: a) by type of energy used technology; b) the degree of substitutability and complementarity energy sources; c) provided for on the operating modes; g) on the planned dates of operation created microgrids; d) in the alleged degree of substitution of energy produced by conventional generating units, green, ie produced from renewable energy sources, energy; e) by the presence of the energy potential in this location for this particular type of renewable energy; g) on the functioning of the regime in relation to centralized networks of higher level; h) according to the degree of autonomy (ability to operate in "island" mode); i) for a number of economic indicators; a) by the presence of the network of consumers, requiring ensure uninterrupted power supply, and their relation to other categories of consumers; l) according to the degree of constancy data generator generating electricity and the possibility of work in "basic" mode.

The most common practice is the next generation system: Northern Electric Networks, micro hydropower plants and biogas plants.

The functions of electric drives in the power system and microgrids are as follows: RES backup power, integrating renewable energy power network of power balancing, load balancing, peak power generation, improvement of power quality, stability, smooth transmission. Currently, the following technology accumulation and regeneration of electricity: hydroaccumulative power, energy storage, compressed air energy storage on the flywheel, superconducting inductive energy storage, supercapacitors; batteries, sodium sulfur battery, the battery and in-line hydrogen energy storage.

For the selection of productive power rubella, chicken was offered technical and economic efficiency criterion. Performance is treated as a specific power developed by a single square meter of the working area of the blades of the wind wheel (W / m2) at a wind speed of 10 m / s. The values obtained showed a large spread of technical and economic criteria of efficiency of WPP.

Technical and economic efficiency of solar energy in the first place depends on the efficiency of photovoltaic modules.

As with any other source of generation, the first and most important condition for the effective functioning of a mini hydroelectric power station is to have the capacity, ie the presence of a river or waterway with high potential in terms of electric power generation. Small hydroelectric power stations, as well as any other type of power plant, works effectively when the utilization of the primary energy source in it corresponds to the modern world standards or higher, and its negative impact on the environment is minimal. Efficient operation of small hydropower plants is provided under two basic conditions: a) selection of optimally suited for hydro turbine hydraulic conditions data with the highest possible efficiency, b) the maximum utilization of the hydropower potential of the dam.

The optimal choice of generation sources for a given micro-network is the key to its successful operation in the future.

The most common sources of electricity generation today are solar and wind power, the power of which varies considerably depending on the environmental conditions. Therefore, in the microgrids should include energy storage, redundant power supplies, as well as generating sources with variable output, which will provide the opportunity to maintain the balance of power generated and consumed within the microsystem.

Increased use of microgrids has good prospects due to the possibilities to further reduce the cost of electricity, as well as a very large range of applications based on power supply technology microgrids with renewable energy for the production of ecologically clean agricultural products, the need for which the market is continuously increasing.

Serious prospects are microgrids for power supply facilities for low-rise construction, the formation of new settlements in the territories or the development of new plots for cottage construction.

The use of microgrids, each of which is an "energy island", opens up great opportunities for energy management of large areas. In this case, the total territory of the power supply circuit will be a system of energy islands, covering the whole territory and connected by a low-voltage lines, which must comply with the energy flows of exchange function of each of microgrids network energositemy and among themselves. Each micro-network consumes all generated energy within it, so the flow will not be significant, which significantly relieve the rural low-voltage network, improve their capacity and reliability.

Conclusions

Proposed and developed the concept of microgrids on the basis of the pre-emptive use of renewable energy, which is a new form of implementation of distributed power ideology, it opens the possibility of the effective use of renewable energy to solve the problem of remote, mainly rural areas, low-rise construction and independent power supply unit separately disposable objects. The importance of the formation of the optimal configuration of microgrids with effective generation sources, selected according to established criteria.