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Author: h.gras
Type: Example
Downloaded: 97 times
Date: 2021-07-23

AC and DC components meter

Description:
This example contains a device which calculates the DC and AC components.
- The DC component is available in the DC control scope with half
a cycle delay versus the simulation time
- ... see moreThe AC component is available in the DC control scope with one
cycle delay versus the simulation time

Once the maximum DC magnitude is reached, the time constant is
determined assuming the DC decay is exponential and uninterrupted

Tag(s): DC, AC, exponential, meters, zero-crossing, asymmetry, fault

Author: Mihajlo
Type: Model
Downloaded: 126 times
Date: 2020-09-04

Active Harmonic Filter

Description:
The shunt filter injects the current that is defined as the error between the (non-linear) load current and the fundamental harmonic. The filter uses a 3-level inverter and the 2-level hysteresis curr... see moreent control.

Tag(s): filter, AHF, active filter

Author: h.gras
Type: Model
Downloaded: 428 times
Date: 2018-06-08

Vacuum Circuit breaker (VCB)

Description:
Three main characteristics of VCBs have been taken into account in the implemented model:
1. the chopping current value;
2. the cold withstand voltage characteristic (or cold gap breakdown v... see moreoltage);
3. the high frequency current quenching capability.

Ref: Transient Recovery Voltages in Vacuum Circuit Breakers Generated by the Interruption of Inrush Currents of Large Motors
A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Sultan, N. Tripaldi

Tag(s): Vacuum, circuit breaker, VCB,

Author: thpapad
Type: Document
Downloaded: 124 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