In this paper, selected aspects of the national technical level of electric energy supply security is shown. An analysis and assessment of the electric power infrastructure in area of generation, transmission and distribution in aspects of electric energy security is conducted. The profile of the generation sector and grid infrastructure in the area of transmission and distribution is shown. The present and future situation in a range of operation of electric power infrastructure in the area of generation, transmission and distribution in the frames of the National Electric Power System in the electric energy supply security context is determined. The level of national electric energy supply security in area of generation and grid infrastructure is assessed. Threats of electric energy supply security are described and the catalogue of essential actions for the assurance of electric energy supply security are proposed. In the area of electricity generation, at present there is no danger to the electricity supply security in normal load conditions, but there is a high probability that it will occur in the future (after 2025) when the forecasted increase in electricity demand takes place and the new stringent environment protection requirements (Directive IED, BAT conclusions, Winter Package) enter into force. The network infrastructure in area of transmission and distribution is admittedly adapted for presently occurred typical conditions of electric energy demand and the realization of internal tasks in normal conditions, but can create a potential threat for electric energy supply security. In the context of the forecasted increase of electric energy demand, inadequate power generation sources in the National Electric Power System and available through intersystem connections, their uneven location on the territory of Poland in the shortage of proper network transmission capacities, the necessity of improvement of the quality and electric energy supply reliability to final consumers and the intensive development of renewable energy sources, the present network infrastructure in area of transmission and distribution will be insufficient.

This work focuses on the concept of operation and possibility of using a tuned inductor in electrical power systems with adaptive features. The idea presented here for the operation of the inductor is a new approach to the design of such devices. An example of a power adaptive system is a device for improving the quality of electricity. The negative impact of nonlinear loads on the operation of a power grid is a well-documented phenomenon. Hence, various types of “compensators” for reactive power, or for both reactive and distortion power, are used in electrical systems as a preventive measure. The concept of an inductor presented here offers wider possibilities for power compensation in power supply systems, compared to traditional solutions involving compensators based on fixed inductors. The use of the proposed solution in an adaptive compensator is only one example of its possible implementation in the area of power devices. In this work, we discuss the structure of the compensator, the basic aspects of the operation of the inductor, the results of simulation studies and the results of measurements obtained from a prototype.

Electric cars (SE) are currently considered to be one of the best ways to reduce CO2 and other air emissions in the transport sector as well as noise in cities. They can reduce the dependency of road transport on imported oil in a visible way. Nevertheless, the demand for electricity for a large amount of SE in road transport is not insignificant and has an impact on the power system. The article analyzes the potential impact of SE on the demand, supply, structure and costs of electricity generation as well as emissions as a result of introducing 1 million SEs by 2025 on Polish roads, and tripling this number by 2035. The competitive electricity market model ORCED was used for the calculations. The results of the analysis indicate that regardless of the charging strategy, the demand for SEs causes a slight increase in the overall electricity demand in Poland and consequently also a slight increase in power generating costs. Even a large increase in SEs in road transport will result in a rather moderate demand for additional generation capacity, assuming that power companies will have some control over the mode of charging cars. The introduction of SEs will not reduce CO2 emissions compared to conventional cars in 2025, on the contrary will increase them regardless of the loading strategy. In 2035 however, the result depends on the charging scenario and both the increase or decrease of emissions is possible. Electric vehicles will increase SO2 net emissions, but they will contribute to a decrease in the net emissions of particulates and NOx.

According to International Energy Agency (IEA) energy security is the continuous supply of energy at acceptable prices. National energy is based primarily on its own energy resources such as hard coal and brown coal. The 88% of electric energy production from these minerals gives us full energy independence. Additionally, the energy production costs from these raw materials are the lowest compared to other technologies. Of these two, the energy produced from brown coal is characterized by the lowest unit technical generating cost. Poland has the resources of these minerals for decades to come, the experience related to mining and processing them, scientific and design facilities and technical facilities and factories producing machines and equipment for their own needs, as well as for export. Coal is and should remain an important source of electricity and heat supply in Poland for the next 25–50 years. It is one of the most reliable and profitable energy sources. This policy may be difficult in the next decades due to the exhaustion of the available resources of hard and brown coal. The conditions for the construction of new mines, and thus for the development of coal mining in Poland, are very interdisciplinary in legal, environmental, economic and reputational terms. Germany has similar problems. Despite the fact that it is an image of a country investing in renewable energy sources, which are pioneers of energy production from RES, in reality hard and brown coal are still the primary sources utilized to produce electric energy.

This paper presents the resolution of the optimal reactive power dispatch (ORPD) problem and the control of voltages in an electrical energy system by using a hybrid algorithm based on the particle swarmoptimization (PSO) method and interior point method (IPM). The IPM is based on the logarithmic barrier (LB-IPM) technique while respecting the non-linear equality and inequality constraints. The particle swarmoptimization-logarithmic barrier-interior point method (PSO-LB-IPM) is used to adjust the control variables, namely the reactive powers, the generator voltages and the load controllers of the transformers, in order to ensure convergence towards a better solution with the probability of reaching the global optimum. The proposed method was first tested and validated on a two-variable mathematical function using MATLAB as a calculation and execution tool, and then it is applied to the ORPD problem to minimize the total active losses in an electrical energy network. To validate the method a testwas carried out on the IEEE electrical energy network of 57 buses.

The single-phase voltage loss is a common fault. Once the voltage-loss failure occurs, the amount of electrical energy will not be measured, but it is to be calculated so as to protect the interest of the power supplier. Two automatic calculation methods, the power substitution and the voltage substitution, are introduced in this paper. Considering the lack of quantitative analysis of the calculation error of the voltage substitution method, the grid traversal method and MATLAB tool are applied to solve the problem. The theoretical analysis indicates that the calculation error is closely related to the voltage unbalance factor and the power factor, and the maximum calculation error is about 6% when the power system operates normally. To verify the theoretical analysis, two three-phase electrical energy metering devices have been developed, and verification tests have been carried out in both the lab and field conditions. The lab testing results are consistent with the theoretical ones, and the field testing results show that the calculation errors are generally below 0.2%, that is correct in most cases.