Exchange Platform

Author: thpapad
Type: Document
Downloaded: 125 times
Date: 2017-11-03

MIMO-OFDM Narrowband-PLC in Distribution Systems: Impact of Power Transformers on Achievable Data Rates

Description:
Power-line communication (PLC) is gaining a renewed interest, due to the smart grid (SG) emerging communication requirements. Among other communication technologies, PLC is a very efficient and feasib... see morele solution, especially for the extended SG distribution networks. However, it is very challenging to consider both the medium- and low-voltage parts of the distribution network as a whole communication medium, due to the attenuating effects of distribution transformers, limiting PLC applicability. In this paper, data transmission through distribution transformers is investigated by means of multiple-input multiple-output (MIMO) narrowband power-line communication (NB-PLC) system, utilizing orthogonal frequency-division multiplexing (OFDM) technology. Multi-conductor distribution line and measurement-based transformer models are developed to characterize the MV-LV PLC channel. In addition, OFDM signal processing techniques are applied to enhance the achievable data rates. The transmit power budget and bit allocation across the OFDM sub-channels of the spatial beams are optimized to maximize the data rate through the distribution transformer. The achievable data rates are calculated and systematically analysed for different scenarios to investigate the effects of the distribution lines, connected loads, noise models, etc. Results reveal the superiority of the proposed MIMO design against the traditional SISO systems. In addition, the possibility for an extensive and reliable application of MV-LV PLC communications through distribution transformers is shown.

Tag(s): Distribution lines, distribution transformers, MIMO-OFDM, power-line communication, smart grids

Author: thpapad
Type: Document
Downloaded: 343 times
Date: 2017-11-03

INDUCED VOLTAGES AND CURRENTS: OVERVIEW AND EVALUATION OF SIMULATION MODELS AND METHODOLOGIES

Description:
In this paper induced voltages and currents caused by underground cables are calculated in cable sheaths and nearby metallic pipelines. The performance of several simulation methods and models are inv... see moreestigated in steady-state, considering also different implementations in ATP-EMTP, EMTP-RV and PSCAD/EMTDC. The analysis is extended in the simulation of transient overvoltages in cable systems, evaluating the accuracy of two widely used simulation models. The influence of different parameters is investigated, among them specifically the earth properties. Results reveal that implementing accurate earth representations, earth conduction effects have a significant impact on induced voltages at the power frequency, while for high frequency phenomena the influence is minor.

Tag(s): induced voltages

Author: h.gras
Type: Model
Downloaded: 166 times
Date: 2017-09-26

LVRT OVRT function

Description:
This device is an OVRT LVRT protection device.
The user enters the curves points.
It is assumed that the curve is horizontal between two points.

Tag(s): LVRT, OVRT, ride, through, FRT, undervoltage, overvoltage

Author: h.gras
Type: Model
Downloaded: 272 times
Date: 2017-08-15

Fault on a line

Description:
This model is a faulty line. The distance of the fault from the origin is a parameter. CP or PI models are used on each side of the fault according to the time step. If the time step is small enough t... see moreo simulate the propagation in the line with at least 10 time steps, CP is used, else it is PI.

Tag(s): fault, line, CP, PI

Author: h.gras
Type: Example
Downloaded: 159 times
Date: 2017-07-12

MOSFET

Description:
The model developed is an n-channel enhancement-type MOSFET with internal substrate (Bulk) connection.
Author: Maxime Berger, Polytechnique Montreal

Tag(s): MOSFET, gate, electronic