Power Line Communication System Research Articles

Power Line Communication Method for the Simultaneous Transmission of Power and Digital Data by Cascaded H-Bridge Converters

Power line communication (PLC) enables the interconnectivity and interoperability of distributed power production units in smart grids and microgrids by using existing cabling to monitor and control the overall power system. In this article, a novel PLC method for cascaded H-bridge converters is proposed, which is based on the use of the circuits of the individual power modules for the transmission of both power and digital information. Compared to the existing PLC approaches, the method proposed in this article combines the advantages of applicability to cascaded H-bridge structures with either a dc or an ac output, avoidance of using an additional power amplifier or coupling circuit for the transmission of information and independence from the implementation scale and the type of the power-supplied load. The design of both the proposed data transmitter and receiver units on field-programmable gate array devices is presented in the article. The proposed PLC system has been applied to an experimental prototype of a two-cell cascaded H-bridge inverter. The experimental results verified the successful transmission of telemetry data through the power converter circuit and their retrieval by a receiver attached in the power loop, along with the simultaneous transmission of power to the load.

Hybrid cooperative spectrum sensing for improving cognitive power line communication systems

This paper introduces a hybrid cooperative spectrum sensing technique that exploits the existing diversity between power line and wireless media with the purpose of improving spectrum sensing functionalities in power line communication (PLC) systems, which operate in the frequency band between 1.7 and 100 MHz. To evaluate the performance of the proposed technique, a data set obtained from a measurement campaign is analyzed, and a feature evaluation reveals that the signal energy is the most relevant feature of all extracted ones. Also, the performance evaluation of the proposed technique shows that the exploitation of the existing diversity between signals acquired from both electric power grid and air can remarkably improve the detection of spectrum occupancy or holes in comparison to the sole use of one of them.

Wavelet-Transform-Based Sparse Code Multiple Access for Power Line Communication

This paper presents Discrete Wavelet Transformed Sparse Code Multiple Access (DWT-SCMA) in Power Line Communication (PLC) systems. In the present internet of things era, PLC provides an established infrastructure for low-cost and reliable indoor connectivity. PLC systems can benefit from the Sparse Code Multiple Access (SCMA) technique, which allows multiple users to access a frequency slot simultaneously to maximize spectrum efficiency. However, interuser interference arises in SCMA when numerous users map their data to the same frequency resource; this, in turn, is likely to be enhanced by the noisy PLC channel. This article adopts the intriguing aspects of DWT to address the interference difficulties. A mathematical model of the proposed technique is also presented and compared with Fast Fourier Transformed SCMA (FFT-SCMA). In the PLC environment, DWT-SCMA is found to outperform FFT-SCMA.

Impact of Lithium-Ion Battery State of Charge on In Situ QAM-Based Power Line Communication

Power line communication within a lithium-ion battery allows for high fidelity sensor data to be transferred between sensor nodes of each instrumented cell within the battery pack to an external battery management system. In this paper, the changing characteristics of the lithium-ion cell at various states of charge are measured, analysed, and compared to understand their effectiveness on the communication channel of a power line communication system for carrier frequencies of 10 MHz to 6 GHz. Moreover, the use of quadrature amplitude modulation (QAM) is investigated to determine its effectiveness as a state-of-the-art modulation method for the same carrier frequency range. The overall results indicate that certain carrier frequencies and QAM orders may not be suitable for the in situ battery pack power line communication due to changes in battery impedance with certain lithium-ion cell states of charge, which cause an increase in error vector magnitude, bit error ratio, and symbol error ratio. Recommendations and trends on the impact of these changing characteristics based upon empirical results are also presented in this paper.

A Resonant Ring Topology Approach to Power Line Communication Systems within Photovoltaic Plants

Within this study, single-cable propagation facilitated by PV strings’ wiring characteristics is considered for an adapted design of PLC electronics. We propose to close the communications signal path, resulting in a ring topology where a resonance condition could be implemented. A PLC topology using the resulting circular closed-loop path of a PV series string as its physical communication support is designed and leveraged for practical use. When the path length or the number of transceivers is changed, the resonance properties that come with the circular path as the physical support are affected but are shown to be preserved with the application of automatic adjustable tuning. This automatic tuning guarantees that the resonance improves propagation parameters and reverts the system to its optimal values at the chosen carrier frequency.

Performance Analysis of STBC-Based MIMO PLC System in Cyclostationary Noise Environment

The paper proposes a multiple-input multiple-output-based power line communication (PLC) system subject to Rayleigh fading and corrupted by additive cyclostationary Gaussian noise. The proposed coherent receiver structure employs a block reception rule at the reception unit for detecting the space-time block-coded transmitted data symbols. A closed-form expression for the pairwise error probability (PEP) is derived using a characteristic function approach. Exact and asymptotic expressions for the average PEP are obtained for the special case of Alamouti code transmission which show that the PLC system under consideration offers full diversity. Numerical results depict the improvement in the system performance with increase in the number of receive diversity branches and the average signal-to-noise ratio per branch and decrease in the correlation value between the noise samples.

The Internet of Things through Internet Access Using an Electrical Power Transmission System (Power Line Communication) to Improve Digital Competencies and Quality of Life of Selected Social Groups in Poland’s Rural Areas

In the 21st century, society has been undergoing a technology-driven transformation which heralds a new revolution that has potential to strengthen the position of an individual and community but may also lead to the marginalization of certain groups. The Internet of Things takes advantage of the technology’s potential to improve digital competencies and the quality of life in society. The purpose of this paper is to obtain information about the digital competencies and needs of contemporary seniors and pre-senior age people, as well as socially sensitive groups from Poland’s rural areas. To strength the level of internet infrastructure in rural areas, power line communication (PLC) systems that utilize high-voltage line(s) between transformer substations are presented as a cost-effective communication tool. PowerLink IP has made PLC systems today more attractive and efficient than ever before. Based on nation-wide representative surveys conducted in deliberately selected groups, we collected information on digital competencies and formulated recommendations pertaining to the structure and contents of an innovative internet portal as regards offering, sharing, and the availability of commercial and social services targeted at seniors and other dependent groups. The recommended portal combines the needs of target groups with interests of entrepreneurs, self-government authorities, and NGOs.

Optimal Rotated QPSK Constellation for a Reliable SOMA Powerline Communication System in Nakagami-m Noise Environment

An <inline-formula> <tex-math notation="LaTeX">${N}$ </tex-math></inline-formula>-branch receive diversity powerline communication (PLC) system with two users and the transmitter employing a power-domain non-orthogonal multiple access (PD-NOMA) along with a rotated quadrature phase-shift keying (QPSK) modulation scheme, generally known as semi-orthogonal multiple access (SOMA) for data transmission is considered in this paper. The rotation of the data constellation and a proposed pre-processing at the receiver end for each user eliminate the usage of the additional successive-interference cancellation (SIC) hardware generally used in PD-NOMA PLC systems. Furthermore, optimal receiver structures are proposed using which closed-form expressions of the symbol error probability (SEP) are derived for the users using a characteristic function (c.f.) approach. The optimal rotation of the QPSK constellation minimizing the obtained SEP of the system is also derived. The diversity order of the system and the optimal angle of rotation at high average signal-to-noise ratio (SNR) values are found to be dependent only on the number of diversity branches. Moreover, the general dependence of the optimal rotation angle on various system parameters is corroborated by numerical results which provide various insights into the design of a reliable and energy-efficient PD-SOMA PLC system without the use of SIC hardware. The optimal rotation angle of the QPSK constellation also leads to novel optimal constellations for the users which are different than the conventional constellation utilized for data transmission in digital communication systems.

A novel front-hauling architecture under centralized radio access network (C-RAN)

Residential power line is considered a cost-effective communication media for building a digital indoor distributed network thanks to its ubiquity in the indoor environment. This paper investigates a front-hauling system under the split centralized radio access network (C-RAN) architecture, aiming to examine the feasibility of implementing common public radio interface (CPRI) over power line communication (PLC) channels. Particularly, we introduce a novel device called CPRI-PLC gateway (CPG) that provides a virtual CPRI link over the PLC channel to ensure high reliability and efficiency in delivering the CPRI hyper-frames (HFs) between the data unit (DU) and radio unit (RU). We examine the proposed CPRI over PLC system via extensive simulations in terms of the achievable throughput and reliability.

Performance Analysis of Dual-Hop Mixed PLC/RF Communication Systems

In this article, we study a dual-hop mixed power line communication and radio-frequency communication (PLC/RF) system, where the connection between the PLC link and the RF link is made by a decode-and-forward or amplify-and-forward relay. It is assumed that the PLC channel is affected by both additive background noise and Poisson&#x2013;Gaussian impulsive noise which suffer from log-normal fading, while the RF link undergoes generalized Rician fading. Based on this model, analytical expressions for the outage probability (OP), average bit error rate (BER), and the average channel capacity (ACC) are derived. Furthermore, asymptotic analyses for the OP and average BER as well as an upper bound expression for the ACC are presented. Illustrative numerical results are presented along with insightful discussions.

Influence of Random Modulated Power Converter on G3 Power Line Communication

Power Line Communication (PLC) technologies are being used in many applications and offer the advantage of utilizing existing power cables for both power and data transmission, thus minimizing cost and complexity. Nevertheless, PLC technology requires further investigation to solve possible co-existence issues. Indeed, recent studies confirmed that alternative modulation schemes such as Random Pulse Width Modulation (RPWM), applied to switching-mode power converters to minimize conducted emissions, detrimentally interfere with the PLC system. This paper presents an experimental test campaign aimed at investigating the effects of RPWM on the G3-PLC system, with the final goal of understanding the conditions under which RPWM schemes can be considered as an effective alternative to conventional Pulse Width Modulation (PWM) in applications involving PLC systems. In details, the effects of different RPWM parameters such as switching frequency, modulation index, and Random Number Update Rate (RNUR) on the G3-PLC is investigated. In addition, different RPWM schemes such as Random Frequency Modulation (RFM) and Random Pulse Position Modulation (RPPM) are compared in terms of performance so as to highlight which RPWM is best suited to assure coexistence with PLC systems. The impact of RPWM on the communication channel is evaluated in terms of Frame Error Rate (FER), Channel Capacity, and Channel Capacity Loss metrics. Experimental results confirmed that randomly modulated converters with switching frequencies near the G3-PLC bandwidth cause more significant disturbance and possible coexistence issues than the switching frequencies out of this range. Results also show that the modulation index and the RNUR of RPWM have a direct effect on the communication channel. Moreover, a trade-off between Electromagnetic Interference (EMI) reduction and coexistence issues is observed: RFM, which is very effective for EMI reduction, is found to be very disruptive for G3-PLC, compared to alternative random modulation techniques such as RPPM.

Power Line Communication with Robust Timing and Carrier Recovery against Narrowband Interference for Smart Grid.

Power line communication (PLC) is an important interconnection technology for the smart grid, but the robustness of PLC transmission is faced with a great challenge due to strong non-Gaussian noise and interference. In this paper, a narrowband interference (NBI) resistant preamble is designed, and an effective timing and frequency synchronization method is proposed for OFDM-based PLC systems in the smart grid, which is capable of simultaneously conveying some bits of transmission parameter signaling (TPS) as well. In the time domain, the cyclic extension of the training OFDM symbol is scrambled, which makes it feasible to combat against NBI contamination. More accurate timing detection and sharper correlation peak can be implemented under the power line channel and the AWGN channel in the presence of NBI, compared with the conventional Schmidl’s and Minn’s methods with the same preamble length. Furthermore, the TPS transmitted using the proposed method is also immune from the NBI. The proposed method is capable of improving the synchronization performance of the PLC transmission significantly, which is verified by theoretical analysis and computer simulations.

Adaptive resource management for cognitive power line communication system

The authors investigate the adaptive resource allocation problem for cognitive power line communication system. The dynamic optimisation model is employed to maximise the energy-aware network utility, which is defined as the difference of the weighted network throughput and the power consumption. Then, the authors decompose the stochastic optimisation into a traffic management subproblem and a joint subchannel and power allocation subproblem. Since the joint subchannel and power allocation subproblem is a mixed integer non-linear optimisation, a continuity relaxation and Lagrange dual method is proposed to obtain the optimal solution of the mixed integer non-linear optimisation subproblem. After that, the authors develop an adaptive power line communication resource allocation algorithm to cope with the power line communication network dynamics only according to the current network state information. Finally, we derive a trade-off mechanism between network utility and network delay, in which the network delay is proportional to the control parameter V and the network utility is proportional to the parameter 1 / V $1/V$ . Simulation results not only show the effectiveness but also verify the theoretical analysis of our proposed algorithm.

Stochastic Network Calculus-Aided Delay Analysis of Wireless-Power Line Mixed Networks

In this paper, we investigate the delay performance of a wireless-power line mixed network via a stochastic network calculus (SNC)-based approach. The data transmission in this mixed network is modeled by a two-stage tandem queue, wherein the data is first relayed through a wireless fading channel and then transmitted over a power line communication (PLC) system. The Rayleigh fading captures the wireless fading channel; whereas, the PLC channel gain is characterized by the log-normal distribution. The statistical characteristics of the service processes of both the wireless channel and PLC channel are derived. With any given traffic arrival and the service capability derived, the delay can be easily bounded via SNC.

In-situ instrumentation of cells and power line communication data acquisition towards smart cell development

The internal core temperature of cells is required to create accurate cell models and understand cell performance within a module. Pack cooling concepts often trade off temperature uniformity, vs cost/weight and complexity. Poor thermal management systems can lead to accelerated cell degradation, and unbalanced ageing. To provide core temperature an internal array of 7 thermistors was constructed; these in conjunction with cell current, via bus bar mounted sensors, and voltage sensor measurements, we have developed instrumented cells. These cells are also equipped with power line communication (PLC) circuitry, forming smart cells. We report upon data from these miniature sensors during cell cycling, demonstrating successful operation of the PLC system (zero errors compared to a reference wired connection) during typical cell cycling (C/2 discharge, C/3 charge) and the application of automotive drive cycle, providing a transient current test profile. Temperature variation within the cell of approximately 1.2 °C gradients, and variation of >2.8 °C during just 30 min of 2C discharging demonstrate the need for internal sensing and monitoring throughout the lifetime of a cell. Our cycling experimental data, along with thorough cell performance tracking, where typically <0.5% degradation was found following instrumentation process, demonstrate the success of our novel prototype smart cells.

The Effective Secrecy Throughput of a Broadband Power Line Communication System Under the Presence of Colluding Wireless Eavesdroppers

This paper investigates the physical layer security of in-home and broadband power line communications (PLC) systems threatened by colluding wireless communication (WLC) eavesdroppers, which are localized near or far from the transmitter and operate in the same frequency band. In this regard, we show that PLC and hybrid PLC-WLC channels can be considered as uncorrelated random processes. In the sequel, we confirm the severity of a WLC eavesdropper or a group of them located near the transmitter. Also, we show that a group of colluding WLC eavesdroppers located far from the transmitter poses the same security risk of only one WLC eavesdropper located near the transmitter. Finally, a discussion of wiretap code rates for achieving effective secrecy throughput is presented.

Power line communication: A review on couplers and channel characterization

&lt;abstract&gt; &lt;p&gt;Powerline communication is gaining momentum with the rise of the smart grid, the Internet of Things as part of the 4th industrial revolution and associated applications such as transportation and energy efficiency. Coupling and channel characterization are essential parts of a power-line communication system. Therefore, understanding these components allows performance evaluation and prediction of the system. This paper presents an entire review of couplers and channel characterization modeling techniques used in narrow and broadband power-line communication systems. Types and applications of different couplers are presented; a review of different power-line communication channel modeling techniques and the fundamentals allows a clear understanding of factors influencing or affecting the signal propagation through the channel. The purpose of this review is to guide researchers and system designers looking for literature resources on couplers and channel characterization for power-line communication applications.&lt;/p&gt; &lt;/abstract&gt;

Interference of Periodic and Spread-Spectrum-Modulated Waveforms with Analog and Digital Communications

In this article, the effectiveness and the limitations of spread-spectrum (SS) modulation techniques employed in switching-mode power converters and in digital systems to mitigate interference with communication equipment are analyzed and discussed under the EMC standard perspective and under an information theoretical perspective, with reference to different real-world scenarios. Substantial difference between potential EMI issues in traditional analog radio/TV broadcasting, digital data lines, and digital links featuring advanced channel coding techniques, e.g. in emerging power line communication (PLC) systems, are highlighted. Practical recommendations on the adoption of SS modulations along with a general reflection on the evolution of EMC requirements are finally given.

A noise reduction scheme for OFDM NB-PLC systems

This paper presents a low-complexity noise reduction scheme for orthogonal frequency-division multiplexing (OFDM)-based power line communication (PLC) systems. The solution exploits the positive time-correlation between the subcarrier noise magnitudes and phases. More specifically, we performed field measurements of PLC noise conducted in seven diverse locations, with continuous measurements for two days, covering the 42 kHz to 471 kHz frequency band. After analyzing the data, we have identified a key PLC noise characteristic; the subcarrier noise magnitudes are highly time-correlated in narrow frequency bands. The same behavior has also been noticed for the subcarrier noise phases. This correlation characteristic has been used to propose a simple and efficient noise reduction scheme for NB-PLC systems. We have applied the proposed method in a real case scenario, where PLC noise field measurements have been used to confirm the advantages in terms of noise reduction gain and bit error rate (BER). Indeed, depending on the channel and used modulation, the proposed scheme is able to reduce the BER by around 35 %, in the considered PLC scenarios.

Electromagnetic Interference of Spread-Spectrum Modulated Power Converters in G3-PLC Power Line Communication Systems

The impact of spread-spectrum techniques used to mitigate EMI from power converters on Power Line Communication (PLC) systems is studied in this paper. A buck converter, utilizing a Random Carrier Frequency Modulation with Fixed Duty cycle (RCFMFD) based control is considered as a source of conducted EMI and a narrowband G3-PLC as the victim. It is shown that, although considered to be an EMI mitigating technique, the spread spectrum technique has a detrimental effect on the communication channel, which can be explained in the framework of Shannon’s information theory. Conventional emission evaluation methods are therefore incompatible with modern day’s technology.