Space-Time-Frequency Diversity for OFDM-Based Indoor Power Line Communication

In this paper, full rate space-time-frequency coding applied to orthogonal frequency division multiplexing based power line communication systems. The proposed systems yield both time and frequency diversity and keep transmission rate full. Performances of the systems are evaluated for three conductors of low voltage indoor cables and are compared with space-frequency and space-time-frequency coding applied power line communication systems in the literature. Owing to the higher order diversity level the proposed full rate space-time-frequency systems have an increasing advantage over space-frequency systems as the SNR level above 12.5dB. On the other hand owing to transmission rate advantage the proposed full rate space-time-frequency systems can have more than 6dB gain over the other space-time-frequency coding applied power line communication systems in the literature

A fitting algorithm for random modeling the PLC channel

The characteristics of the power-line communication (PLC) channel are difficult to model due to the heterogeneity of the networks and the lack of common wiring practices. To obtain the full variability of the PLC channel, random channel generators are of great importance for the design and testing of communication algorithms. In this respect, we propose a random channel generator that is based on the top-down approach. Basically, we describe the multipath propagation and the coupling effects with an analytical model. We introduce the variability into a restricted set of parameters and, finally, we fit the model to a set of measured channels. The proposed model enables a closed-form description of both the mean path-loss profile and the statistical correlation function of the channel frequency response. As an example of application, we apply the procedure to a set of in-home measured channels in the band 2-100 MHz whose statistics are available in the literature. The measured channels are divided into nine classes according to their channel capacity. We provide the parameters for the random generation of channels for all nine classes, and we show that the results are consistent with the experimental ones. Finally, we merge the classes to capture the entire heterogeneity of in-home PLC channels. In detail, we introduce the class occurrence probability, and we present a random channel generator that targets the ensemble of all nine classes. The statistics of the composite set of channels are also studied, and they are compared to the results of experimental measurement campaigns in the literature

Measurement Differences, Faults and Instabilities in Intelligent Energy Systems – Part 2: Fault and Instability Prediction in Overhead High-Voltage Broadband over Power Lines Networks by Applying Fault and Instability Identification Methodology (FIIM)

This companion paper of [1] focuses on the prediction of various faults and instabilities that may occur during the operation of the transmission power grid when overhead high-voltage broadband over power lines (OV HV BPL) networks are deployed across it. Having already been identified the theoretical OV HV BPL transfer function for a given OV HV BPL network [1], the faults and instabilities of the transmission power grid are first differentiated from the measurement differences, which can occur during the determination of an OV HV BPL transfer function, and, then, are identified by applying the best L1 Piecewise Monotonic data Approximation (best L1PMA) to the measured OV HV BPL transfer function. When faults and instabilities are detected, a warning is issued.The contribution of this paper is triple. First, the Topology Identification Methodology (TIM) of [1] is here extended to the proposed Fault and Instability Identification Methodology (FIIM) so that faults and instabilities across the transmission power grid can be identified. Also, the curve similarity performance percentage metric (CSPpM) that acts as the accompanying performance metric of FIIM is introduced. Second, the impact of various fault and instability conditions on the OV HV BPL transfer functions is demonstrated. Third, the fault and instability prediction procedure by applying the FIIM is first reported.Citation: Lazaropoulos, A. G. (2016). Measurement Differences, Faults and Instabilities in Intelligent Energy Systems – Part 2: Fault and Instability Prediction in Overhead High-Voltage Broadband over Power Lines Networks by Applying Fault and Instability Identification Methodology (FIIM). Trends in Renewable Energy, 2(3), 113-142. DOI: 10.17737/tre.2016.2.3.002

Virtual Indicative Broadband over Power Lines Topologies for Respective Subclasses by Adjusting Channel Attenuation Statistical Distribution Parameters of Statistical Hybrid Models (Class Maps) – Part 3: The Case of Overhead Transmission Power Grids

In [1], [2], the theoretical framework and the numerical results concerning the class mapping of overhead and underground medium voltage broadband over power lines (OV and UN MV BPL) topologies have been presented on the basis of the recently proposed initial statistical hybrid model (iSHM), modified statistical hybrid model (mSHM) and class map definition procedure. In this paper, all the recent findings regarding the statistical channel modeling and class mapping are first applied to transmission BPL networks; say, OV high voltage (HV) BPL topologies. The numerical results of OV HV BPL networks are compared against the respective ones of OV and UN distribution networks revealing significant similarities and differences. Finally, the impact of considering minimum or maximum capacity value instead of the average one during the definition procedure is investigated as well as the behavior of the total simulation time of class mapping.Citation: Lazaropoulos, A. G. (2019). Virtual Indicative Broadband over Power Lines Topologies for Respective Subclasses by Adjusting Channel Attenuation Statistical Distribution Parameters of Statistical Hybrid Models (Class Maps) – Part 3: The Case of Overhead Transmission Power Grids. Trends in Renewable Energy, 5, 282-306. DOI: 10.17737/tre.2019.5.3.0010

Performance analysis of orthogonal frequency division multiplexing systems in dispersive indoor power line channels inflicting asynchronous impulsive noise

Hidden semi-Markov modelling of the asynchronous impulsive noise (IN) encountered in indoor broadband power line communications (PLCs) is investigated by considering the statistical distributions of both the inter-arrival time and the duration of asynchronous IN components. Then, the bit error ratio (BER) of orthogonal frequency division multiplexing systems using Q-ary quadrature amplitude modulation is analysed with the aid of the proposed noise model, when communicating over dispersive indoor power line channels inflicting asynchronous IN in addition to the background noise. The authors’ simulation results confirm the accuracy of the analysis and quantify the impact of various factors on the achievable BER performance. The grave impact of asynchronous IN on indoor broadband PLCs suggests that efficient techniques have to be designed for mitigating its effect

Power Systems Stability through Piecewise Monotonic Data Approximations – Part 1: Comparative Benchmarking of L1PMA, L2WPMA and L2CXCV in Overhead Medium-Voltage Broadband over Power Lines Networks

This first paper assesses the performance of three well-known piecewise monotonic data approximations (i.e., L1PMA, L2WPMA, and L2CXCV) during the mitigation of measurement differences in the overhead medium-voltage broadband over power lines (OV MV BPL) transfer functions.The contribution of this paper is triple. First, based on the inherent piecewise monotonicity of OV MV BPL transfer functions, L2WPMA and L2CXCV are outlined and applied during the determination of theoretical and measured OV MVBPL transfer functions. Second, L1PMA, L2WPMA, and L2CXCV are comparatively benchmarked by using the performance metrics of the percent error sum (PES) and fault PES. PES and fault PES assess the efficiency and accuracy of the three piecewise monotonic data approximations during the determination of transmission BPL transfer functions. Third, the performance of L1PMA, L2WPMA, and L2CXCV is assessed with respect to the nature of faults —i.e. faults that follow either continuous uniform distribution (CUD) or normal distribution (ND) of different magnitudes—.The goal of this set of two papers is the establishment of a more effective identification and restoration of the measurement differences during the OV MV BPL coupling transfer function determination that may significantly help towards a more stable and self-healing power system.Citation: Lazaropoulos, A. G. (2017). Power Systems Stability through Piecewise Monotonic Data Approximations – Part 1: Comparative Benchmarking of L1PMA, L2WPMA and L2CXCV in Overhead Medium-Voltage Broadband over Power Lines Networks. Trends in Renewable Energy, 3(1), 2-32. DOI: 10.17737/tre.2017.3.1.002

Measurement Differences, Faults and Instabilities in Intelligent Energy Systems – Part 1: Identification of Overhead High-Voltage Broadband over Power Lines Network Topologies by Applying Topology Identification Methodology (TIM)

This first paper considers the identification of the structure of overhead high-voltage broadband over power lines (OV HV BPL) network topologies by applying the best L1 Piecewise Monotonic data Approximation (best L1PMA) to measured OV HV BPL transfer functions. Even if measurement differences occur during the determination of an OV HV BPL transfer function, the corresponding OV HV BPL network topology may be revealed through the curve similarity of the best L1PMA result compared with the available records of the proposed OV HV BPL transfer function database.The contribution of this paper is triple. First, based on the inherent piecewise monotonicity of OV HV BPL transfer functions, best L1PMA is first applied during the determination of theoretical and measured OV HV BPL transfer functions. Second, the creation procedure of the OV HV BPL network topology database is demonstrated as well as the curve similarity performance metric (CSPM). Third, the accuracy of the proposed Topology Identification Methodology (TIM) is examined in comparison with the traditional TIM with respect to the nature of the measurement differences during the determination of OV HV BPL transfer functions.Citation: Lazaropoulos, A. G. (2016). Measurement Differences, Faults and Instabilities in Intelligent Energy Systems – Part 1: Identification of Overhead High-Voltage Broadband over Power Lines Network Topologies by Applying Topology Identification Methodology (TIM). Trends in Renewable Energy, 2(3), 85-112. DOI: 10.17737/tre.2016.2.3.002