Hungarian Electricity Private (Hungary)

Electricity markets are going through a comprehensive transformation that includes the large-scale appearance of intermittent renewable generators (RGs). To handle the local effects of new RGs on the distribution grid, the more efficient utilization of distributed local flexibility (LF) resources is necessary. However, the optimal market design is not yet known for LF products. This paper investigates a novel cost allocation mechanism in the context of this market challenge. The mechanism is designed to provide several important advantages of peer-to-peer trading without creating barriers to practical application. It provides partial disintermediation. The acquisition of LF remains the responsibility of the DSO, while the financial costs of the transaction are covered on power exchanges (PXs). To provide this functionality, the clearing algorithm of the PX in question has to incorporate a novel feature we call the Payment Redistribution Technique. This technique allows the buyers’ expenses to be larger than the sellers’ income, and the difference is used to finance flexibility costs. Its mathematical formulation is presented and analyzed in detail, considering computational efficiency and accuracy. Afterward, a realistic case study is constructed to demonstrate the operation of the algorithm and its energy market effects.

While the number of internal combustion vehicles is stagnating, and is even expected to decrease in a few decades, the amount of electric vehicles is predicted to increase. Most of the electric cars are designed for daily urban use, thus in the near future, bigger cities might have some ten percentage of electric cars running on their streets during the day. And these vehicles need to be recharged in the evening or during night, so the electric vehicles, including the high performance electric cars, will interact with the power grid in this period. The impact of the charging process is predicted to be apparent on the distribution system, mostly on the low voltage grid, by influencing the network voltage profiles and the loading of the grid elements. As a practical issue we have chosen parts of the LV grid of Budapest, a city with almost two million inhabitants. If 20% of the cars is electric powered, then every fifth household has a car that has to be charged. In this paper we present the results of simulations conducted on the aforementioned grids with chargers placed at different places, using the DIgSILENT Power Factory software package. To get a better view of how electric cars' charging would affect the LV grid, we have run several load flow simulations on a large number of power grids. By statistically analyzing the obtained results, an overall picture can be acquired about the possible issues that electric car charging might have on the electric network of a large city.

The small bulb of the tungsten halogen lamp often operates at several hundred degrees Celsius and an internal pressure higher than atmospheric pressure. The cold lamp contains a gas filling at about 3 bar; the pressure during operation is much higher than that. The objective of our project is to analyse the internal operating conditions (such as the pressure and the thermal behaviour) of certain halogen lamps. The actual measurement of the operating conditions is far from easy. Rather, a computer model has been developed to evaluate the operating conditions in these lamps, based on the substantial partial differential equations of the free convection problem. This model can help determine the temperature distribution, the velocity field and the pressure in these lamps.The free convection has been simulated by the following two appropriate equations: the convection–conduction equation—it is the heat transfer equation for convecting materials—and the incompressible Navier–Stokes equation. We could get the temperature field from our results, which helped us to calculate the operating pressure of the lamps. The pressure dependence on dimensionless characteristic numbers was evaluated.

This paper focuses on the present and future state of the electric power sector, future development of European power systems interconnections and power exchanges, cooperation, and direction of reforming the industry. It discusses the deregulation process and experience in Scandinavia, electricity infrastructure in Hungary, challenges to the German electricity system as part of the western European interconnected system of the Union for the Coordination of Protection and Transmission of Energy (UCPTE), extension of European interconnections to the Black Sea and central African countries, together with the development of a Trans-European synchronized power system as seen from the East. It also examines the current situation and policy of Russia, Ukraine, Belarus, and Moldova taking into account the recently created new independent states (NIS).

The paper describes a simple method, based upon the Fourier transformation of the frequency, active and reactive power deviation time functions which are modeled and measured in field tests, to determine the efficiency of excitation systems and power system stabilizers (PSS). Employing this "Fourier transform method" for the space variables mentioned above, numerical values are given to evaluate the damping effect of the exciter system and PSS, without any switching operations on the power system. The results show the source and the magnitude of the oscillations for the unit, power plant and power system investigated.

Various tests were performed on glass cap insulators under laboratory conditions. According to the laboratory control for diagnostic methods, the direction finder, the ultrasonic detector and the night vision system can be recommended. Laboratory methods were selected for a systematic insulator diagnosis on porcelain cap insulators. Electromechanical parameters of the aged insulators may be reduced to half the original value, to far below the required values. The power frequency wet test proved the ageing for other type of insulator string too. The monitoring of leakage current impulses helps to follow the procedure.