Narrowband Power Line Communication Research Articles

Enhancing safety in narrow-band transformerless PLC couplers with a passive symmetrical filter

As the demand for efficient data transmission over existing power infrastructure grows, power-line communication (PLC) systems have become increasingly vital. However, integrating communication signals with high-voltage power lines poses significant safety challenges, emphasizing the need for reliable, safe, and high-performance components. To address cost and safety concerns, this article introduces a symmetrical third-order band-pass filter design that employs a transformerless coupler, avoiding the expense and bulk of traditional transformers while enhancing both equipment and human safety in narrow-band PLC systems. The design, functionality, and safety considerations are discussed, with a focus on implementing a passive analog Butterworth filter, chosen for its flat frequency response in the passband. Additionally, we address the safety aspects of transformerless couplers in PLC applications, emphasizing their reliability and efficiency in maintaining signal integrity while minimizing the risks associated with high-voltage environments. Simulations validated the proposed design, confirming its effectiveness in achieving the desired frequency response. The design is cost-effective due to the elimination of the transformer and ensures safety through the strategic rearrangement of the coupler components, which isolates the power line from the communication side.

Optimal Passive Power Line Communication Filter for NB-PLC Applications

Narrowband Power Line Communication (NB-PLC) involves transmitting data by overlaying a high frequency low amplitude signal (ranging from 9 kHz to 500 kHz) onto the low-frequency high amplitude signal (50 Hz to 60 Hz) of the power grid. While using the existing power grid for communication is convenient, it was not originally designed for this purpose, leading to challenges such as conducted emissions and infrastructure constraints. To overcome these technical obstacles, power line filters (PLFs) are a viable solution. The results of our research work, focusing on the optimization of PLFs for NB-PLC to ensure their design fits the needed use case while avoiding over-engineering, are presented in this article. Our study concentrates specifically on the filtering of PLC signal and conducted emissions up to 500 kHz. Building upon a PLC PLF extensively discussed in our previous work—which blocks the PLC signal in the CENELEC-A frequency band regardless of its placement within the electrical installation, sometimes leading to over-engineering—this research aims to adapt the filter order and components for a variety of real scenarios in CENELEC-A, FCC, and ARIB frequency bands. By characterizing different filters, our work provides tailored solutions for these scenarios and serves as a framework for future filter designs in PLC applications.

Empirical Characterization of Non-Intentional Emissions generated by PV Installations

Non-Intentional Emissions (NIEs) generated by solar photovoltaic (PV) systems have significantly increased concerns about disturbances in the 9-150 kHz band of the lowvoltage distribution grid, which can lead to failures or cause thermal stress in the devices connected to the grid. Moreover, these emissions can cause interference in narrowband power line communications (NB-PLCs). This paper presents a characterization of emissions generated by different real PV systems. Specifically, measurement campaigns were carried out in isolated PV systems, which employed different panel configurations, as well as in a grid-connected system. The analysis of the NIEs allows the identification of the frequencies and amplitudes of the emissions, as well as the evaluation of the NIEs variation over time. In addition, the impedances of the PV systems were also measured to correlate impedance variations with emissions.

Emissions generated by electric vehicles in the 9-500 kHz band: Characterization, propagation, and interaction

Electric Vehicle Charging Processes (EVCPs), due to the involved power electronics with high-switching frequencies, generate high-amplitude emissions that could have a negative impact on Power Quality (PQ) and Narrowband Power Line Communications (NB-PLC) systems. In this context, this paper deals, first, with the frequency and time characterization of the disturbances generated by four EVCPs in the 9-500 kHz frequency range. The study is based on measurements carried out in a controlled Low Voltage (LV) grid. For this purpose, a novel procedure for the frequency and time characterization is proposed. The frequency characterization is based on the calculation of a set of parameters, which allows evaluating not only the amplitude of the disturbances in the frequency band under analysis, but also their spectral distribution. The time variability is characterized by means of a Fast Fourier Transform (FFT) analysis that leads to a simplified model to evaluate the time-dependent behavior of the disturbances, which shows a sub-cycle periodic pattern of the emissions in the frequency band of interest. Second, the propagation of the previously characterized emissions is analyzed, concluding that they propagate several meters through the LV grid. Although in most cases the disturbances are attenuated with distance, there might be resonances that lead to higher amplitudes at an electrical point distant from the source of the emissions. Finally, the influence of the simultaneous charging of several EVs is studied. The results show that, in general, the amplitudes correspond to the superposition of the individual disturbances, in addition to intermodulation products due to the switching frequencies of the inverters.As a conclusion, the high amplitude time-varying emissions, together with their capacity for propagation and interaction, are a matter to be analyzed due to their influence on PQ and their potential degradation of the performance of PLC in the frequency band from 9 kHz to 500 kHz.

Characterization of Non Intentional Conducted Emissions Up to 500 kHz in Urban Environment

The current interest in Europe to extend the frequency range for Narrowband Power Line Communications up to 500 kHz requires a thorough characterization of the non intentional emissions in this frequency range. This paper presents results of field measurements carried out in a dense urban environment, where the electrical devices are quite numerous and located at a short distance from the smart meters, and therefore, the effects of the non-intentional emissions on Smart Grids communications may be noticeable. In the study, spectral and time characterization of the recorded data was performed according to CISPR specifications, and then compared to recommended limits for non-intentional emissions in this frequency range. Results show that the levels of the emissions above 150 kHz may exceed the recommended limits for spurious emissions in the frequency band, mainly near the smart metering devices, due to the nearness of different types of electrical devices connected to the grid. This work demonstrates the need of characterizing the non-intentional emissions up to 500 kHz for the proper performance of future Smart Grid applications in this frequency range.

The Environmental Impacts of Radio Frequency and Power Line Communication for Advanced Metering Infrastructures in Smart Grids.

In the neighborhood area network (NAN), the advanced metering infrastructure (AMI) enables a bidirectional connection between the smart meter (SM) and the data concentrator (DC). Sensors, such as smart meter nodes or environmental sensor nodes, play a crucial role in measuring and transmitting data to central units for advanced monitoring, management, and analysis of energy consumption. Wired and wireless communication technologies are used to implement the AMI-NAN. This paper delves into a novel approach for optimizing the choice of communication medium, air for radio frequency (RF) or power lines for power line communication (PLC), between the SM and DC in the context of the AMI-NAN. The authors methodically select the specific technologies, RF and NB-PLC (narrowband power line communication), and meticulously characterize their attributes. Then, a comparative analysis spanning rural, urban, and industrial settings is conducted to evaluate the proposed method. The overall reliability performance of the AMI-NAN system requires a packet error rate (PER) lower than 10%. To this end, an efficient approach is introduced to assess and enhance the reliability of NB-PLC and RF for AMI-NAN applications. Simulation results demonstrate that wireless communication is the optimal choice for the rural scenario, especially for a signal-to-noise ratio (SNR) lower than 25 dB. However, in urban environments characterized by higher SNR values and moderately dense networks, NB-PLC gains prominence. In denser networks, it outperforms wireless communication, exhibiting a remarkable 10 dB gain for a bit error rate (BER) of 10-3. Moreover, in industrial zones characterized by intricate network topologies and non-linear loads, the power line channel emerges as the optimal choice for data transmission.

A review on the empirical characterization of the low voltage distribution grid as a communication channel for power line communications

The electrical grid was not designed for the transmission of communication signals, which are affected by impedance variations, attenuation, and Non-Intentional Emissions (NIEs) in their propagation through the Low Voltage (LV) distribution grid. For this reason, the characterization of the electrical grid as a transmission medium is of vital importance for the correct development of Power Line Communications (PLC) technologies and the optimization of the opportunities offered by the LV distribution grid as a communication infrastructure. This paper deals with the state-of-the-art, challenges to be faced and future work of the characterization based on field trials in real scenarios. First, the features of Narrowband Power Line Communications (NB-PLC) and Broadband Power Line Communications (BB-PLC) technologies are outlined, including a brief comparison between the already developed NB-PLC protocols and providing an overview of the evolution of BB-PLC. Then, the parameters to be measured on the characterization of the LV grid are described, in addition to including the particularities and problems of the measurement systems designed for this aim. Finally, the state of the art and future work concerning the characterization of the outdoor LV grid as a transmission medium based on field trials are gathered.

Interference Level Detector with PCB HDI Rogowski coil for PLC Narrow-Band Applications.

This article presents and discusses the structure, principle of operation, and operational properties of a newly developed interference level detector (ILD) designed to measure conducted supraharmonic disturbances (1-150 kHz) in the power grid and to assess the effectiveness of narrow-band Power Line Communication (PLC) transmission, especially in the PRIME technology. The usability assessment was made on the basis of the validation and the results of tests carried out in a low-voltage network with non-linear loads. Appropriate practical conclusions were then formulated.

Proposals for Updated EMC Standards and Requirements (9–500 kHz) for DC Microgrids and New Compliance Verification Methods

This paper is aimed at making new proposals for developing future Electro-Magnetic Compatibility (EMC) standards tailored to DC microgrids in a frequency range between 9 and 500 kHz. In particular, new EMC proposals are made to reduce Electro-Magnetic Interference (EMI) with arc hazard detection and narrowband power line communication (PLC). To achieve this, first, arc detection requirements, PLC standards and existing EMC standards are reviewed. Next, new proposals are made to specify EMC requirements for equipment in DC microgrids in terms of conducted emission, immunity (9–500 kHz) and minimum impedance requirement (>40 kHz). The minimum impedance requirement is a new type of requirement and the relevant compliance testing method is developed. The new EMC proposals also distribute frequency bands to support arc detection and narrowband PLC. Then, to show the feasibility and advantage of proposed EMC codes, this paper develops a new arc detection method, which relies on only measuring the arc noise voltage (40–100 kHz) in a single point of the grid and does not need one or more current measurements. A total of three test cases are presented to show the feasibility of the arc detection method and the significance of having an EMC minimum impedance requirement. The executed tests for this paper also show that new EMC proposals are feasible and promising for DC microgrids. This concept and approach are the major novelties of this paper. The specific EMC threshold levels for conducted noise, immunity, and impedance within a frequency range between 9 and 500 kHz will need to be further fine-tuned based on the microgrid application parameters and further gathering of experimental data.

Passive Power Line Communication Filter Design and Benchmarking Using Scattering Parameters

NB-PLC (narrowband power line communication) is a method of data communication that involves superimposing a relatively high-frequency signal (9 kHz to 500 kHz), which contains data, onto the power grid’s low frequency (50 to 60 Hz) signal. While using the existing power grid as a transmission medium is convenient, the power grid was not designed for this purpose, leading to challenges such as conducted emissions and infrastructure limitations. To overcome these technical challenges, passive filters are necessary. This article presents the design, simulation (using scattering parameters), and evaluation of an NB-PLC filter by comparing it to commercially available filters. Our proposed design and benchmarking methods enable the accurate prediction of the filter’s behavior in field conditions. After comparing our filter with commercially available filters, we observed that it exhibits superior characteristics. Specifically, our filter has the best insertion loss versus frequency, achieved three times higher attenuation at 50 kHz (−130 dB) compared to the best commercially available filter (−40 dB), and has a power consumption of 0.6 W, which is comparable to the most power-efficient commercial filter (0.5 W). Additionally, our filter has the second best input and output impedance of 3.6 Ω within the frequency range of 35–95 kHz.

Performance Analysis of Orthogonal Multiplexing Techniques for PLC Systems with Low Cyclic Prefix Length and Symbol Timing Offset.

This paper investigates the degradation caused by interference resulting from cyclic prefix violation and symbol timing offset in narrowband power line communication systems. In this sense, it presents a unified formulation from which Hermitian symmetric orthogonal frequency division multiplexing (HS-OFDM), orthogonal chirp division multiplexing (OCDM), single-carrier cyclic prefix (SCCP), and orthogonal time-frequency division multiplexing (OTFDM) can be easily derived. The paper then provides closed-form expressions for quantifying the aforementioned interference in the presence of a frequency domain equalizer. The numerical analyses exhibit the performances of these schemes under various data communication conditions, such as the availability of channel state information, the presence or absence of interference, modeling of additive noise as a white or colored Gaussian random process, frequency domain equalizer type, and the use of bit and power allocation techniques. The closed-form expressions and performance analyses regarding achievable data rate and bit error probability provide guidance for dealing with distinct constraints in narrowband power line communication (PLC) systems using the HS-OFDM, OCDM, SCCP, or OTFDM scheme. Lastly, the unified formulation and results obtained motivate the design of multi-scheme transceivers.

Smart Utilities IoT-Based Data Collection Scheduling

The Internet of Things is an ecosystem that connects billions of smart devices, meters, and sensors. These devices and sensors collect and share data for use and evaluation by organizations in different industry sectors. Humans may use the IoT to live and work more intelligently and gain total control over their lives. Consequently, IoT can be used to connect devices and integrate them with new digital technologies for customers. On the other hand, smart utility companies in the electric, gas, and water sectors need to deliver services more efficiently and analyze their operations in a way that can help optimize performance, detect growing problems in real time, and initiate fixes to avoid unplanned service interruptions. Building actual smart metering networks is costly and time-consuming. Therefore, in this paper, a new Smart Utilities Traffic Scheduling Algorithm (SUTSA) is proposed. To minimize the system complexity, the model is based on narrowband power line communication, in which a wired hidden network sends data across power lines. A simulation is performed using OPNET Modeler 14.5 to evaluate the proposed model. The results proved that the proposed model is highly scalable and achieves full network-bandwidth utilization in different situations based on different application requirements.

A Notch Filter-Based Coupling Circuit for UNB and NB PLC Systems

This paper introduces an analog notch filtering-based coupling circuit for receivers in ultra-narrowband and narrowband power line communication systems, which are connected to low-voltage electric power grids. It is composed of a twin-T notch analog filter, which is responsible for imposing a significant attenuation on the main frequency (i.e., f0∈{50,60} Hz) in cascade with an elliptic low-pass analog filter, designed with a 3 dB cut-off frequency of fc≫f0. For f0=60 Hz and fc=2 MHz, the prototype of the analog notch filtering-based coupling circuit attains attenuation values of 22 dB and less than 2 dB at the main frequency and in the rest of the frequency bandwidth, respectively, when practical scenarios are considered. Lastly, it shows that the analog notch filtering-based coupling circuit is more effective than a typical capacitive coupling circuit when frequencies lower than 3 kHz are considered for data communication and sensing purposes.

Inductive coupling-based narrowband PLC systems for overhead MV power distribution networks: New insights

This paper advances the investigation of the adequacy of inductive coupling-based narrowband power line communication (PLC) systems in overhead medium voltage power distribution networks (MV-PDNs). Relying on raw data obtained from a measurement campaign which was carried out in urban and rural feeders in the south region of Brazil, it shows that overhead MV-PDNs may be a challenging data communication media when considering inductive coupling devices since the level of insertion losses associated with the coupling process is relevant. Also, the presence of significant loads between the source and destination nodes can severely degrade loops of currents, which are necessary to perform data communication in an inductive coupling-base PLC system, resulting in an erasure data communication media. For the reliable links (i.e., without erasure), the performance analysis shows that PLC channel impulse responses and additive noises can be respectively modeled as time-invariant systems with a quasi-flat channel frequency magnitude and white Gaussian random processes in urban and rural areas. Last but not least, an attenuation model and achievable data rates are discussed for the reliable links.

Investigation and Field Measurements for Demand Side Management Control Technique of Smart Air Conditioners located at Residential, Commercial, and Industrial Sites

This paper investigates the response and characteristics of the narrowband power line communication (NB-PLC) technique for the effective control of electric appliances such as smart air conditioners (SACs) for demand side management (DSM) services. The expression for temperature sensitivity by examining the influence of atmospheric temperature variations on power consumption profile of all possible types of loads, i.e., residential, commercial, and industrial loads is derived and analyzed. Comprehensive field measurements on these power consumers are carried out in Lahore, Pakistan. The responses of low voltage channels, medium voltage channels, and transformer bridge for a 3–500 kHz NB-PLC frequency range are presented for DSM services. The master control room transmits control commands for the thermostat settings of SACs over power lines, crossing the transformer bridge to reach the SACs of power consumers by using communication protocol smart energy profile 1.0. The comparison of hourly and daily power consumption profiles under evaluation loads, by analyzing typical and variable frequency air conditioners on setting thermostat temperature at 25 °C and 27 °C conventionally and then by using DSM control technique, is analyzed. A prominent reduction in power consumption is found with the implementation of the DSM control technique.

Power Line Communication as Alternative for Data Communication Channel for BRT

The goal of intelligent transportation system (ITS ) for Bus Rapid Transit (BRT) is to improve public transportation in relation to safety, usability, mobility, quality and productivity through the use of information and communication technology and one of the main problems is to ensure that which elements of ITS such as buses, sensors, actuators, traffic lights, among others are exchanging data with them, due to the size of this environment, the infrastructure of communication between the transportation management system (TMS) and ITS components is extremely important in this context, this work proposes the use of communication technologies called Power Line Communication (PLC) system, which consists of data communication through the grid network that is available in urban center. Another characteristic of ITS for BRT is that the environment will exchange small data packages, so it is possible to use narrow band technologies. In this paper was considered the evaluation of two initiatives on narrow band PLC, PRIME and G3, which have similar physical layer, and the PRIME privileges the high data rates during favorable conditions and G3 provides better performance on unfavorable conditions. The both projects can be used as a communication data channel for communication between BRT ITS elements, because this communication requests a low bit rate.

Error Analysis of Narrowband Power-Line Communication in the Off-Grid Electrical System.

Narrowband power-line communication seems to be a suitable communication technology designed for off-grid renewable energy solutions. Existing electrical installations can be designed both for the transmission of electricity and for the communication of electrical equipment operating inside such an installation. This study presents an implementation of the above-mentioned off-grid communication system and examines the basic problems related to its exploitation. The authors of this article focused their attention primarily on examining the disturbance of the communication channel caused by the use of typical electrical devices, such as: a light bulb, a kettle, etc. used in a household. The aim of the research was also to find the impact of switching on individual devices and their combinations on the disturbances during data transmission. Measurements of incorrectly transmitted data packets were carried out and then the test results were referred to the error measures. Moreover, the influence of the carrier frequencies on the signal attenuation and the method of eliminating the existing interferences were also discussed.

Power Line Communication Over Flexible Cables for Elevator Cabins

Narrowband power line communication has become a major focus of research with its applicability extending to residential facilities. This article examines data transmission over flexible AC power line cables stretching from the elevator control panel to the cabin. In previous studies, there has been no significant attempt to characterize the Power Line Communication (PLC) channel and noise of an elevator system. In this article, a vector network analyzer and mixed domain oscilloscope along with coupling devices are used to conduct power line channel noise and response measurements for an elevator system. The acquisition of channel transfer functions corresponding to both idle and moving states of the elevator is carried out for the 9 kHz–500 kHz frequency range. A mathematical model is provided for the average frequency response of the PLC channel. The main source of noise is the inverter that supplies power to the motor. The channel exhibits notable variations for frequencies less than 281 kHz while staying relatively consistent for the 281 kHz to 500 kHz frequency range as the elevator changes from idle to moving state. Reed Solomon and convolutional codes along with interleaving to spread erroneous bits are utilized in this work to simulate an orthogonal frequency division multiplexing transceiver. By systematically selecting subcarrier frequencies that do not overlap with the harmonic noise components, simulation results have demonstrated reliable data recovery for signal-to-noise ratio greater than 4 dB.

Long-Term Noise Characterization of Narrowband Power Line Communications

Noise modeling in power line communications has recently drawn the attention of researchers. However, when characterizing the noise process in narrowband communications, previous works have only focused on small-scale phenomena involving fine-grained details. Nevertheless, the communication link's reliability is also affected by long-term noise phenomena that might affect transfer rates at higher layers as well. This paper addresses the problem of long-term noise characterization for narrowband power line communications and provides a statistical analysis of the long-term trends affecting the noise levels. We present a statistical description of the noise process in the time and frequency domains based on real field measurements in the FCC band (10 kHz–490 kHz). The collected data comprises more than 1.8 billion samples taken from three different locations over a time period of approximately ten days. The noise samples have been statistically analyzed by considering stationarity, autocorrelation, and independence. Although our results—being unprecedented—are interesting per se, they improve the noise pattern knowledge, thus paving the way for the design and implementation of more robust PLC protocols.

A capability of power line communication for HEMS of smart grid on traditional home power grid in Thailand

Abstract This research was conducted on the ability of Power Line Communication (PLC) technology to communicate data for home energy management system through the traditional home electrical grids in Thailand. The study found that the Narrow-Band Power Line Communication (NB-PLC) is most suitable for smart home applications and safe for health of the residents. The results showed that the efficacy of PLC is mostly dependent on the service life time factor of the cables. The regression rate of signal level for the newest electric wire (1–15 years) is 83% lower than the oldest (30–45 years) and 47% lower than the middle life time (16–30 years). Also, the regression rate of signal level for the middle life time was 69% lower than the oldest wire. Whereby we could predict the signal level according to the changing length and service life time of electric cable. In this research, it was found that the carrier frequencies also are influence on the signal level of the power line communication. The signal level of KNX PL110 standard which used the frequency range 105 and 115 kHz is higher than the signal level of IDIS that used the frequency range 63.3 and 74.5 kHz and the regression of signal level of KNX PL110 standard is 68% lower than the IDIS standard. The experimental results also showed that baud rate “2400” is the best for power line communication because it generates more stable signal levels.