Holger Hirsch

Simulation of powerline communication with OMNeT++ and INET-Framework

This paper presents the work that is done embedded in the EEnergy project [1] “E-DeMa” [2] to simulate powerline communication systems (PLC) for access and inhouse applications in a smart grid scenario. The simulation is implemented in a C++ builder using OMNeT++ [3] and its sub module INET [4]. OMNeT is an event based network simulation tool, and INET is a collection of common network units and technologies, so far excluding powerline. First, the rudiments of the implementations are presented - second, a real network to verify the simulation is described and third, the results are compared and analyzed.

European MIMO PLT field measurements: Overview of the ETSI STF410 campaign & EMI analysis

PLT systems available today only use one transmission path between two outlets. It is the differential mode channel between the phase (or live) and neutral contact of the mains. These systems are called SISO (Single Input Single Output) modems. In contrast, Multiple Input Multiple Output (MIMO) PLT systems make use of the third wire, PE (Protective Earth), which provides several transmission combinations for feeding and receiving signals into and from the low voltage distribution network (LVDN). This paper gives an overview of the ETSI STF410 field measurement campaign which was performed in roughly 40 homes in six European countries. The measurement setup - including the couplers used - is described. The MIMO measurements include channel transfer function, noise, reflection and EMI measurements.

HiL simulation of electric vehicles in different usage scenarios

This paper describes the simulation of an electric vehicle drive train via a hardware in the loop (HiL) setup in combination with an interactive driving simulator based on MATLAB/Simulink. This setup provides the possibility to test the suitability of electric vehicles in different usage scenarios using a laboratory environment. Another aspect is that by a comprehensive analysis of the measurement data, system components of the drive train can be tested under realistic conditions and further developed in order to improve the efficiency of such vehicles.

UWB Pulse Transmission over Powerline Channel

The EMI/EMC problem of PLC needs to be seen not only from the channel point of view, but also from that of the communication signal to be transmitted. One way by which the EMI problem between different co-existing transmission systems in the wireless environment was addressed is by using a carrier-less UWB pulse transmission. In this paper the advantage of using UWB signals over OFDM signals for PLC applications is outlined, the way forward in adopting the UWB system for the PLC environment is discussed, alternative approach in minimizing the ISI for branched PLC channels is proposed, simulation and measurement results are presented, achievable data rates are indicated, dispersion properties of PLC channels are also analyzed. PLC channel models of up to three branches have been used in the simulation and measurements. The EMI/EMC is the focus behind this work, and hence other communication system implementation and performance measures such as matched filtering, BER, etc, are not part of this work, these subjects have been discussed in detail in the references.

Optimum grounding grid design by using an evolutionary algorithm

A new application is proposed for getting the optimum design of grounding grids. The basic design quantities of the grounding grids are the ground resistance (Rg), the ground potential rise (GPR), touch and step voltages. These mentioned quantities depend on the grid parameters, which are its side lengths, radius of grid conductors and length of vertical rods. The dependence of the design quantities of the geometric parameters is given by field computation based on equivalent charges by using a combination of charge simulation and image methods.The effect of the location profile that the earth surface potential through it is calculated, and also the vertical rods length, and its position is studied. Numerical example is introduced to explain the performance of this method and its ability to give valuable information about the grid configuration that satisfies optimization.

Surface Potential Calculation for Grounding Grids

One of tasks of the grounding systems is to maintain the voltage rise due to discharging fault current into grounding grids at the minimum value to insure the safety of public and personnel. The objective of the paper is to make a comparison between the addition of horizontal rods and vertical rods to the grounding grids to improve the performance of it. A boundary element approach uses to get the numerical computation of grounding system analysis such as the equivalent resistance and the distribution of potential on the earth surface due to fault currents. This study describes the importance of vertical ground rods not only decrease the grounding grid resistance but also reduce the step and touch voltages.

Investigations on the Impact of Different Electric Vehicle Traction Systems in Urban Traffic

Currently electric vehicles are introduced in e.g. public transport and individual traffic in order to reduce i.a. the green house gas emissions. The main disadvantage of electric vehicles compared to vehicles with conventional drive is the shorter operating distance. In contrast this disadvantage is partially negligible in urban usage scenarios, like e.g. taxi or delivery services. This paper focuses on the simulation of electric vehicle propulsion systems using a Hardware in the Loop (HiL) model. The model consisting of components used in actual electric vehicles is scaled using Buckinghams Pi-Theorem in order to analyze the impact of different electric traction systems on the vehicles energy consumption. Thus the available operating distance of such vehicles can be optimized in urban traffic.

Improved Design of Square Grounding Grids

Vertical ground rods are the simplest and commonly used means for earth termination of electrical and lightning protection systems. It plays an important role when adding to the grounding grid to improve the performance of it by reducing not only the grid resistance but also the step and touch voltages to values that safe for human. A boundary element approach uses to get the numerical computation of grounding system analysis such as the equivalent resistance and the distribution of potential on the earth surface due to fault currents. The paper investigates the effect of vertical rods location on the value of the grid resistance, step and touch voltage. It presents some cases of square grids to explain the best case that satisfies the best grid performance and economical cost.

Measurement of earth surface potential using scale model

Determination of the earth surface potential distribution due to discharging impulse current into grounding grids is difficult by using numerical methods. One way to measure the earth surface potential (ESP) and to study the transient performance of grounding grids subjected to impulse lightning current is using a scale model of the grounding grids with an electrolytic tank, because if all dimensions of the grid is reduced by the same factor, the percentage of the mesh voltage is unchanged and also the shape of current and equipotential surfaces is unaltered. Therefore, it is possible to simulate the actual grounding grids with the help of scale models and the potential profiles measured on a model may be used to determine the corresponding potentials on a full scale grid. The discharging impulse current is injected at the corner of the grid and the potential at different points along different profiles on the surface of the water filled the electrolytic tank is measured. The results obtained from the experimental work provide guidelines for safe design of the grounding systems.

Coexistence analysis of access and indoor powerline communication systems for Smart Grid ICT networks

In the context of enabling a comprehensive ICT infrastructure for the Smart Grid including Automatic Meter Reading (AMR) and Demand Side Management (DSM), the coexistence of narrowband and broadband access and indoor powerline communication systems is essential, since neither the customers accept performance loss of their private indoor networks, nor the Meter Reading Operator or Distribution System Operator can operate its Smart Grid components efficiently. Therefore, in this paper a coexistence testbed is introduced in order to investigate the influence of narrowband and broadband access systems on the customers indoor networks. Even though their operating frequencies do not overlap, also common narrowband powerline communication systems using the CENELEC A band can cause a significant performance decrease on an OFDM-based broadband powerline communication system, which operates in the frequency range of 2 MHz to 30 MHz, when using the same mains. These effects are investigated in detail and the results show the spectral behavior of the interacting systems, their performance data and coexistence with other systems. It is shown that the performance decrease on the BPLC system can be nearly nullified by introducing an additional filter.