Пропозиції щодо пошуку економічних місць розташування та величин потужності джерел розподіленої генерації в розподільних електричних мережах, які живляться від системного електропостачання

Анотація

SUGGESTIONS ON SEARCH OF ECONOMIC PLACES OF LOCATION AND THE MAGNITUDES OF POWER THE SOURCES OF DISTRIBUTED GENERATION IN DISTRIBUTION ELECTRIC NETWORKS, WHICH ARE POWERED BY THE SYSTEMIC ELECTRICITY SUPPLY

A.M. Skrypnyck, D.P. Kozhan

Introduction. The introduction of SDG (such as solar and wind energy converters, hydroelectric power plants on small rivers, etc.) in distribution electric networks ensures the cleanliness of the environment, reduces both fuel and water resource costs, and energy losses in networks by approximating the manufacturers of electric energy to consumers. At that, there are problem issues associated with both the regime of voltage in the network with the SDG, and the impact of SDG on the properties of centralized systemic electricity supply.

Problematic is also the questions about determine the economic places of location of SDG in distribution networks and the values of their active and reactive capacities, taking into account the distribution between the supplying network of objects. To address these issues in this publication we propose an approach in two stages:

1) definition the economic places of location SDG;

2) determination of the values of active and reactive capacities of the SDG in the places of their economic location.

The purpose of the research – the development of simple and effective models search of economic places of location and the magnitudes of power of SDG in distribution electric networks, which are powered by the systemic electric supply.

Materials and methods of research. To determine the economic places of location of SDG in distribution electric networks, which are powered by the systemic electricity supply, a gradient method is used that implements specific transport costs for the transmission of active and reactive power to the elements of the electrical network.

Specific transport costs ∂π / ∂P_i and ∂π / ∂Q_i are determined for all nodes of the electric network scheme on the basis of the results of calculations of the modes of its maximum or prospective node load.

The maximum values of the nodal specific transport costs ∂π / ∂P_i and ∂π / ∂Q_i indicate the most economical locations of the sources of active and reactive power respectively.

In open-loop networks with voltage of 10 and 35 kV, which have several branches from node systemic power supply, the maximum values of nodal specific transport costs, and accordingly the most economical places for installation of power sources, are defined separately for each offshoot.

At that, all search active and reactive power are determined directly without additional their calculation after the end of the iterative process.

Experimental studies on the above-stated approach in two stages are performed on the example of a fragment of the scheme of an electrical network of 10 kV voltage with parameters of the plots and values of the nodal load.

Conclusions and perspectives.

1.  Using the method of specific transport costs provides the possibility of developing simple and effective models to determine economically sound locations SDG in distribution electric networks, which are powered by the systemic electric supply.

2. To determine the economically feasible capacity SDG with their location in economically sound areas it is proposed to use a modified Newton method with the definition of amendments to unknown at each step of the iterative process solution of the system of linearized equations using the least squares method.

3. A modified Newton method, which is the addition of the matrix of partial derivatives the derivatives ∂ε_i^P / ∂P_i; ∂ε_i^P / ∂Q_i; ∂ε_i^Q / ∂P_i and ∂ε_i^Q / ∂Q_i provides the ability to use nodal characteristics P_і, Q_і, θ_і і U_і in various combinations search and known nodal values.

4. Experimental studies have shown, when determining capacity SDG in distribution networks 10 kV, the most appropriate is the equality of voltage of 10.5 kV in the places where electricity producers join, including the place of system power supply.

Research is being conducted on the use of specific transport charges on the reactive-power ∂π / ∂Q_i and modified method of Newton for the choice of optimal places of location and the magnitude of sources of reactive-power for her indemnification in distributive electric networks.

It is planned to use the methodic with respect to the economic justification of the locations and magnitudes of the power SDG and their optimization in the distribution electrical networks when changing graphs for nodal the consumption.