An open data repository for steady state analysis of a 100-node electricity distribution network with moderate connection of renewable energy sources

The data of this article represent a real electricity distribution network on twenty kilovolts (20 kV) at medium voltage level of the Hellenic electricity distribution system [1]. This network has been chosen as suitable for smart grid analysis. It demonstrates moderate penetration of renewable sources and it has capability in part of time for reverse power flows. It is suitable for studies of load aggregation, storage, demand response. It represents a rural line of fifty-five kilometres (55 km) total length, a typical length for this type. It serves forty-five (45) medium to low voltage transformers and twenty-four (24) connections to photovoltaic plants. The total installed load capacity is twelve mega-volt-ampere (12 MVA), however the maximum observed load is lower. The data are ready to perform load flow simulation on Matpower [2] for the maximum observed load power on the half production for renewables. The simulation results and processed data for creating the source code are also provided on the database available at http://dx.doi.org/10.7910/DVN/1I6MKU.


a b s t r a c t
The data of this article represent a real electricity distribution network on twenty kilovolts (20 kV) at medium voltage level of the Hellenic electricity distribution system [1]. This network has been chosen as suitable for smart grid analysis. It demonstrates moderate penetration of renewable sources and it has capability in part of time for reverse power flows. It is suitable for studies of load aggregation, storage, demand response. It represents a rural line of fifty-five kilometres (55 km) total length, a typical length for this type. It serves forty-five (45) medium to low voltage transformers and twenty-four (24) connections to photovoltaic plants. The total installed load capacity is twelve mega-volt-ampere (12 MVA), however the maximum observed load is lower. The data are ready to perform load flow simulation on Matpower [2] for the maximum observed load power on the half production for renewables. The simulation results and processed data for creating the source code are also provided on the database available at http://dx.doi.org/10. 7910 The data are ready to perform loaf flow simulation for the maximum observed load power on the half production for connected renewables.

Experimental features
The data are based on Matpower format for load flow, power system analysis.

Data source location
The line on which these data are based is located in Greece Value of the data The source code represents a real distribution network of moderate but adequate size. It is ready to perform steady state analysis. The data are suitable for studies in load aggregation, storage, demand response and consequently for the optimal design of distribution grid's topology. Their format on Matlab [3] allows for quick and easy integration with emerging technologies and/or proven scientific methods.
The fact that these data are based on a real distribution grid enhances the applicability of the research to be conducted. The dimensioning of the lines, loads and generators currently corresponds to an operational network. Consequently, the results of the upcoming research using these data have the prerequisites to be also technically suitable to be applied by a network operator.
The bibliography provides a wide selection of open source data for power system applications.
CIGRE [4] and IEEE [5,6] networks are regularly used but they are focused to high voltage transmission lines even if they provide examples on the distribution. Smart grids are regularly deployed to distribution level and a wide selection of networks could contribute to their implementation. This dataset seeks to cover the gap providing only line data on this voltage level additionally to the data already available.
Our open source data are available for performing steady state, load flow analysis of the given network. However, further enhancement in terms of line and generators data could facilitate shortcircuit and dynamic calculations and consequently to support protection and stability studies. This is part of future work but further information is required to increase results accuracy.

General information
On the technical level, smart grids as such are considered an advanced discipline. The scientific community and the industry have allocated resources in describing and solving the main challenges as far as the interconnection of several types of facilities to the distribution level are concerned. However, additional effort needs to be allocated in achieving homogeneity in conducting smart grid simulations. This approach requires taking into consideration the specifics of each system and requires the accessibility to real networks to perform the research. Several organisations offer open source data of electricity grids. CIGRE [4] and IEEE [5,6] networks are the commonly used. There are  [8]. Additional datasets are available to the bibliography.

Line description
In any case, the distribution lines will remain the backbone of the distribution that is not going to change. Based on this way of thinking, this manuscript provides open access to a real distribution network line with the following special characteristics. It represents a rural line of fifty-five kilometres (55 km) total length, of a typical length for this type. It serves forty-five (45) medium to low voltage transformers and twenty-four (24) connections to photovoltaic plants. The total installed load capacity is twelve mega-volt-ampere (12 MVA), however the maximum observed load is lower. The connection points are given according to Table 1. The names of the nodes have been changed from the original ones in order to meet MATLAB requirements. All the above are provided below and at the attached online dataset (http://dx.doi.org/10.7910/DVN/1I6MKU).

Loads and generations
This line serves forty-five (45) medium to low voltage transformers that mostly serve the loads. Their connection points, their installed capacity and the maximum, minimum observed active and reactive loads are provided at Table 2.

Experimental design, materials and methods
The line is constructed using Aluminium Conductors Steel Reinforced (ACSR) of 16 mm 2 , 35 mm 2 and 95 mm 2 . Their electrical characteristics are provided to Table 4. The accuracy of the simulations was decided to three decimal places.
To perform load flow analysis on Matpower, we have chosen per unit system. The base power is 10 MVA since this corresponds safely to the operation margin of the line. The base voltage is of 20 kV,  operates. This decision for the base power and voltage leads to a base impedance of 4 Ω. Consequently, all resistances and reactances and expressed in per unit and the length is taken into consideration. The calculations are available on the excel file available to the data repository (Table 5).