Power Line Communication Research Articles

Resilient Consensus-Based AC Optimal Power Flow Against Data Integrity Attacks Using PLC

This paper investigates the resilience of consensus-based AC optimal power flow (OPF) for distribution networks against the data integrity attacks (DIA). The distribution network is first decomposed into several autonomous microgrids to achieve consensus-based AC OPF through the alternating direction multiplier method (ADMM). Then the vulnerability of consensus-based AC OPF is analyzed by showing how the dispatch results can be easily altered by attackers through falsifying the information (active power, reactive power, and voltage) shared between neighboring microgrids. Two different attack scenarios, viz., economic-driven attacks and disruptive attacks, are studied to show the malicious influence of cyber attacks on consensus-based AC OPF. A detection and mitigation strategy based on the existing power line communication (PLC) infrastructure is then described, where the critical information is not only shared in the cyber layer, but also through the power lines. Game-theoretic analysis is provided to demonstrate the effectiveness of the proposed mitigation strategy. Furthermore, to validate the authenticity of the information through PLC, a physical encryption method based on the Lorenz system is proposed. The effectiveness of the proposed attack-resilient mechanism is verified using the IEEE 123-bus test system.

DSSE in European-Type Networks Using PLC-Based Advanced Metering Infrastructure

This paper addressesthe problem of real-time state estimation in European-type four-wire low-voltage distribution networks with advanced metering infrastructure based on power line communication (PLC). The main drawback of this type of infrastructure is its high latency and a sequential data sampling process. Both factors make it difficult to obtain instantaneous values from the smart meters in a timely and adequate manner to estimate the real-time state of the system. This problem may be solved in the future with the deployment of metering systems based on other technologies such as 5G. However, PLC technology prevails in many countries, and is not likely to be replaced in the medium term. In the meantime, a solution is needed to provide acceptable real-time state estimates in low voltage networks, not to hinder the active management of these assets in the context of smart grids. In this work, a solution is proposed that allows estimating the state of the low voltage network with a reasonable accuracy considering the low quality of the measurements provided by the deployed infrastructure. The system is validated using a portion of a real pilot network located in the north of Spain fed by a transformer station with seven feeders.

An Efficient Reconfigurable Encoder for the IEEE 1901 Standard

The IEEE 1901 standard for power line communication (PLC) enables simple connection among Internet of Things devices. The forward error correction (FEC) codes specified in the IEEE 1901 standard include low-density parity-check convolutional codes (LDPC-CCs) and Reed-Solomon convolutional concatenated (RSCC) codes. This work introduces an efficient reconfigurable encoder in full compliance with the IEEE 1901 standard. First, we propose a reconfigurable LDPC-CC encoder to fulfill the multirate requirement and improve the architecture by fine-tuned parallelization, which takes full advantage of the characteristics of the codeword structure. Then, for area reduction, the optimization regarding the RSCC encoder is extensively exploited. Moreover, the commonality between the encoders is discovered, and some circuitries are shared to reduce the hardware complexity. Equipped with these techniques, an efficient reconfigurable encoder for the IEEE 1901 standard is developed and implemented with 28-nm technology. Implementation results demonstrate that the proposed encoder can meet the throughput requirement of the IEEE 1901 standard and is both power- and area-efficient.

Minimization of Energy-Efficient Outage Probability in AF-Relayed PLC

Energy-aware resource allocation to achieve desired throughput over cooperative power line communications (PLCs) has gained growing interest from past few years. In this article, we design an energy-efficient amplify-and-forward relay-assisted PLC, where outage probability based on energy-efficiency is minimized by jointly optimizing the relay location and power allocation (PA) in two scenarios: 1) absence and 2) presence of the end-to-end direct link. To reduce complexity, using a novel and nontrivial approach, we obtain a closed-form expression of the outage probabilities for both the scenarios. Further, an equivalent problem is formulated to make the optimization problem more tractable to obtain its solution. In the absence of direct link, a closed-form solution of the problem is obtained by the optimization schemes where underlying variables are optimized individually and jointly. While, in the presence of the direct link, a closed-form solution is obtained using a nontrivial tight approximation algorithm. Via numerical results, the outage expressions are validated, and various insights on optimization of PA and relay location are obtained. Finally, with respect to energy-efficiency, it is shown that the joint optimization gives an outage improvement of around 55% and 37% in the absence and presence of the direct link, respectively.

Efficient Low-Complexity Optimized Channel Estimating Methods for OFDM-Based Low-Voltage Broadband Power Line Communication Systems

Broadband Power Line Communication (BB-PLC) technology enables data transmission for smart grid applications. Nevertheless, channel equalizers are required in the receiver to estimate and compensate for the nonlinear time-variant impulse response and noise interference effects introduced by the BB-PLC channel. In this paper, we append the Particle Swarm Optimization (PSO) algorithm and its proposed improved version to the commonly used Least-Square (LS) and Linear Minimum Mean Square Error (LMMSE) algorithms to advance four new blocktype pilot-aided hybrid channel estimation algorithms for low-voltage Orthogonal Frequency Division Multiplexing (OFDM)-based BB-PLC systems. Extensive numerical simulation results for four different M-QAM formats (M = 8, 16, 32, 64) show that the proposed algorithms significantly improve the performance of the traditional LS and LMMSE estimators, at least for the parameters of the BB-PLC system studied in this work. In addition, the computational load complexity of the PSO-inspired LMMSE algorithm is lower compared to the conventional LMMSE estimator.

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.

PLC Physical Layer Link Identification with Imperfect Channel State Information

This paper proposes an accurate physical layer technique to uniquely identify the links of a power line communication network. First, the power line communications (PLC) multipath channel characterization is presented and detailed. Then, a multipath channel delay detection technique is introduced to provide an accurate physical layer identification (PL ID) for the considered PLC links. The accuracy and efficiency are tested by evaluating the successful path detection probability (SPDP) in a simulated scenario under both perfect and imperfect channel state information conditions. The results confirm the advantages of the proposed scheme. Indeed, for a common PLC noise power around 90 dBuV, the provided accuracy reaches ≈90%, while for a noise power below 80 dBuV, the accuracy plateaus at 100%. Overall, the low complexity of the proposed approach and its staggering performance results pave the way for further possible applications in both the PLC and the security domain.

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.

Multiple Industrial Induction Motors Fault Diagnosis Model within Powerline System Based on Wireless Sensor Network

The voltage supply of induction motors of various sizes is typically provided by a shared power bus in an industrial production powerline network. A single motor’s dynamic behavior produces a signal that travels along the powerline. Powerline networks are efficient at transmitting and receiving signals. This could be an indication that there is a problem with the motor down immediately from its location. It is possible for the consolidated network signal to become confusing. A mathematical model is used to measure and determine the possible known routing of various signals in an electricity network based on attenuation and estimate the relationship between sensor signals and known fault patterns. A laboratory WSN based induction motors testbed setup was developed using Xbee devices and microcontroller along with the variety of different-sized motors to verify the progression of faulty signals and identify the type of fault. These motors were connected in parallel to the main powerline through this architecture, which provided an excellent concept for an industrial multi-motor network modeling lab setup. A method for the extraction of Xbee node-level features has been developed, and it can be applied to a variety of datasets. The accuracy of the real-time data capture is demonstrated to be very close data analyses between simulation and testbed measurements. Experimental results show a comparison between manual data gathering and capturing Xbee sensor nodes to validate the methodology’s applicability and accuracy in locating the faulty motor within the power network.

TENG-inspired LED-in-capacitors for smart self-powered high-voltage monitoring and high-sensitivity demodulation of power-line communications

Increasing voltage levels and realizing power-line communications are important parts of a smart grid, and because of this, the need for intelligent, digital, and multi-functional electronic sensors that can simultaneously perform the functions of high-voltage monitoring and carrier-signal demodulation in a power transmission system is urgent. Inspired by the operation mode of light-emitting diodes (LEDs) driven by triboelectric-nanogenerators (TENGs), we propose an electrode-LED-electrode structure, namely, LED-in-capacitors (LIC), for high-voltage monitoring and high-frequency signal demodulation. We demonstrate that the proposed LIC can sensitively extract the high-voltage amplitude and detect the harmonic pollution on a power line due to the LIC’s being highly sensitive to the rate of change of the electric potential. We build a one-dimensional convolutional neural network that we use to identify successfully, with correct rate as high as 94.53%, the harmonic pollution. Additionally, by using the LIC, we are able to demodulate accurately the high-frequency carrier signals transferred in the high-voltage line, showing that the LIC has promise for potential applications in power-line communications. As a novel type of electronic device derived from TENG-related technology, we believe the LIC can provide impetus for the development of next-generation high-voltage technology.

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.

Performance and Capacity Analysis of MDCSK-BICM for Impulsive Noise in PLC

To further mitigate the BER error floor of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$M$</tex-math></inline-formula> -ary differential chaos shift keying (MDCSK) modulation for impulsive noise, a low-cost high-reliability coded modulation scheme without equalizations is desirable for impulsive noise. In this paper, a protograph-based low-density parity-check coded MDCSK-based bit-interleaved coded modulation (MDCSK-BICM) scheme is proposed for the scenario with impulsive noise obeying Bernoulli-Laplace distribution. Considering the Gaussian distribution of protograph extrinsic information transfer (PEXIT) and the benchmark of coding design, the U-shaped non-coherent capacity is derived with optimal code rate for square MDCSK, showing that the code rates are stable with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$E_b/N_0$</tex-math></inline-formula> increasing but still much lower than that of DS-16DQAM at code rate <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&gt;\!0.145$</tex-math></inline-formula> . The derived joint probability density function can be considered as approximately a Gaussian distribution, which is used to improve the impulsive noise fitted PEXIT. Finally, a new code under a novel principle is designed for better bit error rate performance based on the improved PEXIT analysis. Both PEXIT analysis and simulation results demonstrate that the proposed scheme achieves a better BER than that with a traditional scheme, and suggesting a research approach based on simple methods. This basic research work provides a guide to establish a framework and optimize the performance of transmission systems over practical power line communication.

Reconfigurable Turbo and Low-Density Parity-Check (LDPC) Decoding Accelerators for Powerline Communications

This study presents two reconfigurable turbo/low-density parity-check (LDPC) decoding kernels for the two powerline communication standards, HomePlug and G.hn. Two architectures are presented, both of which use the radix-4 double-binary enhanced max-log maximum a posteriori probability algorithm with next-iteration initialization in turbo decoding. In LDPC decoding, the two architectures employ the normalized min-sum and the layered radix-4 forward and backward algorithms. The two algorithms cause differences in the architecture and throughput rate. Consequently, the proposed decoding kernels have different architectures when combined with the turbo decoding algorithm, and the two proposed decoding kernels each have their own advantages and disadvantages in terms of throughput and area cost. To make the features of two kernels more evident, we have implemented the proposed decoding kernels that lead to significant throughput gains and better area efficiency compared with other studies. The proposed decoding kernels can be operated in all modes specified in the HomePlug and G.hn standards using a 40-nm complementary metal-oxide-semiconductor (CMOS) process. Moreover, the proposed decoding kernels provide different solutions to achieve the expected throughput rates of the G.hn and HomePlug standards.

Power Line Communication and Sensing Using Time Series Forecasting.

Smart electrical grids rely on data communication to support their operation and on sensing for diagnostics and maintenance. Usually, the roles of communication and sensing equipment are different, i.e., communication equipment does not participate in sensing tasks and vice versa. Power line communication (PLC) offers a cost-effective solution for joint communication and sensing for smart grids. This is because the high-frequency PLC signals used for data communication also reveal detailed information regarding the health of the power lines that they travel through. Traditional PLC-based power line or cable diagnostic solutions are dependent on prior knowledge of the cable type, network topology, and/or characteristics of the anomalies. In this paper, we develop a power line sensing technique that can detect various types of cable anomalies without any prior domain knowledge. To this end, we design a solution that first uses time-series forecasting to predict the PLC channel state information at any given point in time based on its historical data. Under the approximation that the prediction error follows a Gaussian distribution, we then perform chi-squared statistical test to build an anomaly detector which identifies the occurrence of a cable fault. We demonstrate the effectiveness and universality of our sensing solution via evaluations conducted using both synthetic and real-world data extracted from low- and medium-voltage distribution networks.

Memory Channel Models of a Hybrid PLC-VLC Link for a Smart Underground Mine

In this article, discrete memory channel models of a low-cost, visible light communication (VLC) and a hybrid amplify-and-forward (AF) powerline communication (PLC) and VLC channel are derived using data obtained from an underground mining testbed. The testbed is set up close to the mining face, where blasting occurs. Then, the noise distributions as a result of the connection of a blasting equipment and the mains switchboard supply on the powerline channel are modeled. The baseband signals are communicated over software-defined radios, using multicarrier modulation in the VLC and hybrid AF PLC-VLC channels. Aided by a Fritchman 3-state semi-hidden Markov model (SHMM) for channel state classification, the channels are modeled using a first-order (FO) Markov process, which considers only one previous state in the channel. In addition, the block diagonal (BD) Markov model, which groups similar successive states of the channel, is implemented in order to reduce the training complexity. The models for the error distribution are then derived for both VLC and hybrid PLC-VLC channels. Results show that the probability of error obtained from the trained models closely matches the probability of error obtained from the channel measurements, validating the suitability of the SHMM for modeling VLC and hybrid PLC-VLC channels. In addition, the modified BD Markov model, which groups the channel states shows better performance with reduced complexity when compared with the FO Markov model.

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.

A survey on the integration of visible light communication with power line communication: Conception, applications and research challenges

The extensive enhancement of wireless communication industry over the last decade revolutionized the change of our daily life. In this scenario, it becomes utmost difficult for the network providers to cater the needs of the end users. Consequently, this mandates the necessity to rely on alternative communication-based technologies. Therefore, one such communication is visible light communication (VLC) which is regarded as a promising complement to radio frequency (RF) based wireless communication. The renowned nature of VLC is that it renders simultaneous illumination and communication by utilizing light emitting diodes (LEDs). However, VLC by itself cannot be employed directly as an information source. Therefore, this necessitates for VLC to be connected to a backhaul network to furnish communication. Based upon these grounds, power line communication (PLC) turns out to be the most feasible communication technology which reinforces as an excellent communication backbone for VLC systems. Predominantly, the inherent benefit offered by the integrated PLC–VLC systems is that the existing power line infrastructure can be leveraged to supply power to the LED, while the energy-efficient LED-based illumination systems render wireless support. Accordingly, this paper presents a comprehensive review of the integrated PLC–VLC systems, physical layer aspects which includes detailed study on PLC–VLC channel modeling and modulation techniques. In addition, this survey focuses in detail on the multiple access techniques and clearly discusses several technical aspects that are associated with the cascaded PLC–VLC systems as well as highlights the current state-of-the-art research aspects in the directions of hybrid PLC-VLC-RF systems. Additionally, this survey outlines the societal applications of PLC–VLC systems which includes the applications of PLC–VLC in hospitals, aircrafts, military, Internet of Things (IoT) devices, etc., as well as summarizes the challenges that are of paramount important while designing high speed integrated PLC–VLC systems.

Improvement of SCADA-Based Preventive Control Under Budget Constraints

Catastrophic disasters in real-world systems, such as large-scale blackouts in power grids, are usually triggered by minor incidents, which culminate in a complex cascading failure in an interdependent system. Because the loss of a power transmission line disrupts the control information piggybacked on the line, failures in the power network may consequently disrupt monitoring and control of the system. Hence, reliable functioning of the communication network in support of monitoring and control is vital to ensure that the re-dispatch-based preventive control effectively restricts cascade propagation. In this paper, we address this issue by proposing a novel scheme in designing the communication network comprised of both power line carrier communication (PLCC) links and non-PLCC (e.g., microwave) links in preparation of possible failures under a budget constraint on the communication link deployment cost. First, we characterize the fundamental hardness of our problem. Next, we develop a solvable Mixed-integer linear programming (MILP)-based algorithm, which attains a constant-factor approximation under certain conditions. Finally, we show via simulations on the IEEE 118-bus system that the proposed algorithm achieves superior performance in terms of enabling more accurate topology estimation and more served demand in the face of cascades.