Expected increase in plug-in electric vehicle (PEV) sales makes different analysis of their impacts on electricity distribution networks very interesting. This paper analyses the impacts of PEV charging on an example of a real low voltage (LV) distribution network for various PEV penetration scenarios (5 %, 10 %, 20 % and 50 %). Two main charging technologies were modelled: slow charging at private charging stations and fast charging at public charging stations. Two basic charging modes were analysed: unregulated and regulated. The analysis was done in a professional software tool for analysis of LV distribution networks: WINDis. The results have shown that PEV charging can have negative impacts in terms of increased peak load, increase of power losses, overload of transformers and lines, decrease of voltage values and increased voltage asymmetry. It has been shown that the LV network can support regulated slow charging of a large number of PEV's.

This paper describes modelling procedure for calculating energy stresses of transmission line surge arresters. A 110 kV shielded transmission line is modelled using ElectroMagnetic Transient Program – Restructured Version (EMTP – RV). Some parts of transmission line such as transmission line towers and stations on both ends of line are modelled thanks to EMTP – RV possibility of grouping electrical elements into subcircuits. Also it was possible to create subcircuit consists of number of other subcircuit. This possibility was very important for dividing transmission line into number of sections that consists of number of towers. Arrester current and voltage, energy duty, insulator voltage and voltage on tower top due to bipolar lightning are calculated and presented.

A lightning experiment is conducted on the 123 kV single-circuit transmission line Ston – Komolac located in the area of Dubrovnik (Croatia), which has a very high lightning ground flash density. This line is equipped with ga pless line arresters. This experiment has been operational for 6 years and presently includes, after several upgrades, the fol l wing elements: On two towers the shape of the transient currents circulating through the 3 line surge arresters are measured with Pearson’s sensors; in addition a specially develope d Rogowski coil has been installed around both towers to measu re the lightning current circulating through them. These sensors are connected to a real time monitoring system, energiz ed by a solar panel, with a communication system making use of a mobile phone network to transmit the measurement data to a remote server, in order to avoid the burden of on-site vis its to get the measurements. This monitoring system had been prese nt d in previous papers [1][2]. At the line remote end subs tations some Rogowski coils measure the lightning current through the station arresters, and measurements of currents and voltage at the secondary side of the measuring transformers are ma de too. All the lightning measurements are compared with the data obtained from the lightning detection system coveri ng Croatia (LINET). It was shown that the consistency of these 2 sources of information is quite satisfactory. Since the beginning of the experiment many measurem ents have been obtained, some of them corresponding to v ery strong lightning strokes. In this paper we are presenting examples of measurements, some statistics of the transient curr ents circulating through the line arresters and some comparisons between measurements and EMTP-like calculations.

Anticipated mass production and integration of plug-in electric vehicles (PEV) in the power system asks for the analysis of the impacts of PEV charging on different aspects of power system operation. This paper presents the analysis of the impacts of PEV charging on the example of a part of a real medium voltage distribution network from the Bosnia and Herzegovina. Three different charging technologies were modelled: slow charging at private charging stations, fast charging at public charging stations and ultrafast charging at DC charging stations. Three charging modes were analysed for slow charging: unregulated, regulated and regulated with Vehicle-to-grid (V2G) intervals. The analysis showed that the charging of PEV's has negative impacts on the distribution network in terms of the increase of peak load, the increase of energy losses, the negative impact on voltage profiles and the overload of distribution transformers. By regulating the process of PEV charging most of the negative impacts can however be reduced.

Remote-distance interactive learning is an important emerging educational trend. The Internet is an ideal medium for remote instruction purposes. This paper describes an innovative real-time remote-access to high voltage laboratory. As an example, an application of remote experiment on measuring and calculating electromagnetic (EM) fields of power frequency 50 Hz inside the high voltage laboratory is described, which can be easily accessed trough the Internet. Students can watch the experiments in real time from a remote workstation, hear the sounds in the laboratory, and interact with other laboratory users.

This paper presents a new monitoring system in the lightning measurement field. This system is presently used to measure the transient currents circulating through some line arresters installed on a transmission line located in Croatia, the total lightning current flowing through a telecom tower in Corsica as well as the transient currents inside its base station. Data are acquired in real-time at several locations and transmitted to a remote server.

The ultimate goal when designing the HV apparatus is to prevent the breakdown appearance during the operational conditions. In this paper we present the modeling approach for the optimal design of HV devices. Here we combine several tools that in an automatic iterative loop converge to the final, breakdown-free design. The integrated framework contains the module for BEM-based field computation, the tool for free-form optimization of the real-world problems and the controlling tool for breakdown criteria evaluation. In each iteration step after calculating the field distribution, the new instance of the possible final design is proposed by the module for the free-form optimization and checked by tool for the automatic control of the breakdown appearance. The brief description of the techniques used within the integrated framework (simulation / optimization / controlling) is given. Special attention is paid to the optimization approach. Here we use the gradient-less free-form optimization approach for both direct (sensitivity-less) and indirect (simple sensitivity-based) optimization. The procedure is illustrated by some examples of the optimization of the real-world apparatus (switches, circuit breakers). The optimal design proposed by the simulation is verified by the laboratory tests.

A new remote laboratory system is introduced in order to achieve real-time distant operation. Next to the cameras that permit the viewing of the experiment, it is also possible remotely to control the equipment and to get the results. Only requirements are network infrastructure present close to the laboratory, and communication ready equipment with a serial port for example. 1. INTRODUCTION Web based laboratories are a well-known topic with new solutions appearing every year [1-4]. This paper introduces a new laboratory monitoring system that enables the remote viewing and control of the experiments. Based on Internet protocol, it communicates over any available networks such as Internet and Intranet, making it accessible worldwide. 2. PURPOSE 2.1. Application field Two applications fields are of interest. For the university, a remote monitoring laboratory permits that several faculties follow the same experiment over the network. For the industry, the same monitoring system enables final product evidence testing to several clients. First advantage of this monitoring system is to have access to a remote laboratory wherever the end user is located. Also the software control of the equipment over the network enables that no more local crew is required inside the laboratory. At the university level, same experiment followed by different teachers, assistants and students leads to a homogenization of knowledge as well overall progress. Another point is that there is no more need for each faculty to purchase same expensive equipment, thus leading to a reduction of the costs. For the industries, remote equipment experiment permits that final client witness product testing over the network without the need to be physically present inside the laboratory. The whole test is saved in digital format with cameras for evidence and future viewing. Results of the experiment are saved in digital format as well, and can be used easily later on with common programs such as MS Excel. 3. SYSTEM PRESENTATION Own developed monitoring system is in charge of generation, acquisition and communication in the remote laboratory. It consists of an industrial motherboard with memory and solid-state disk shown in Figure 1. Figure 1: Monitoring system controller and acquisition card. Whole system is fanless and without any mechanical parts such as hard drives in order to reduce the risk of system failure. The controller of the monitoring system is connected with the generation equipment toward USB or RS232 ports. This link enables the transmission of the generation …