Low Voltage Power Line Research Articles

Research on Power Line as Communication Channel with Multi-Tap and Multi-Branch Configuration

To study the effect of different branch configuration on transmission characteristic in-home low-voltage (LV) communication power line communication (PLC) channel, the influences of branch length, number of branch and tap, and branch terminal impedance on the performance of PLC are investigated. The two type power line network structures of the one-tap with multi-branch (OTMB) and the multi-tap with multi-branch (MTMB) are studied. The transmission characteristics of the PLC channel are simulated by varying the length and terminal impedance of the branch for two configurations. Simulation results show that the length and terminal impedance of the branch have significant influence on the amplitude and phase response of the transfer function. The position and number of notches and crests in the amplitude responses are affected by different branch types and the configurations of branch length and branch terminal impedance. The models developed in this paper can easily handle an arbitrary topology of power line channel and provide accurate calculation for the channel responses of the all kinds of channel branch structures in indoor LV power line network

지중 저압 전력선의 협대역 전력선통신 채널특성 및 적용성에 대한 연구

본 논문은 국내 지중 저압선에 대한 협대역 PLC 기술의 통신 채널 특성과 이를 기반으로 한 적용성 연구결과에 대해 기술한다. 지중 저압선이 매설된 실제 거주지역에 협대역 PLC 채널 측정을 위한 시스템을 구성하였으며, 이를 통해 채널 응답, 잡음 PSD, 선 임피던스를 포함하는 채널 특성을 측정하였다. 측정된 채널 특성을 분석하여 국내 지중 저압선의 채널 특성이 협대역 PLC 적용에 적합한 특성을 띠며, 250kHz 이후 주파수 대역이 특히 양호한 특성을 나타내는 것을 보였다. 이를 기반으로 IEEE P1901.2 규격을 채택, FCC High 대역을 이용하여 네트워크 테스트를 수행하였으며 이를 통해 국내 지중 저압선에 협대역 PLC 기술의 적용이 가능함을 확인하였다. This paper presents in details channel and noise characteristics over narrow bands below 500kHz based on the field tests over underground low voltage(LV) power lines in residential areas in Korean grid. We show that the channel characteristics of narrowband signals over underground LV power line are decent. We first describe methodology of channel characteristic measurements including channel frequency response, noise, and line impedance, and obtain channel characteristics over the underground LV lines in the residential areas. Also based on the measurement results, we adopt the IEEE P1901.2 standard on the FCC High band, and bring up narrow band power line communication network.

Carrier Modulation Technology Based on Orthogonal Frequency Division Multiplexing

This paper first analyzes the transmission characteristics of low-voltage power line channels with the focus on the study of carrier modulation technology regarding the power line communication part, then proposes the orthogonal frequency division multiplexing technology that serves for the digital communication of family network power line communication gateways, analyzes the OFDM system principle, actulizes OFDM modulation and demodulation through discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT), and build the OFDM simulation model. Finally, a specific plan of using power lines as the family network transmission media is proposed.

Research on the Technology of Low-Voltage Power Line Carrier-Current Communication Based on OFDM

The design on the system of low-voltage power line carrier-current communication based on OFDM was finished in this paper. Then model of the system was simulated and the modulation and demodulation of OFDM were realized. The results show that the integral performance can be enhanced with channel code. And the bit error ratio (BER) of the system is different with several sub-carrier wave modulation modes. This system could satisfy the requirement of power line communication basically.

Smart Detection Technology of Serial Arc-Fault on Low Voltage Power Lines

It is important to use electric power safely. Electric arcing faults on the low voltage power lines must be detected and power sources have to be shut down before fire hazards. In this paper, it suppose a method to analyze and detect arc fault characteristics. The current waveforms are different in arc fault and normal operation conditions. The discrete wavelet transform is used to obtain the spectrum characteristics of experiment data and the spectrum energy statistics can reflect the characteristics. Additionally, the values of spectrum energy are input of the back-propagation neural networks (BPNN), which can identify the arc fault efficiently. The test results have demonstrated that the proposed method is effective.

Measurement and Analysis of the Low-Voltage Power Line Narrowband Carrier Channel Attenuation

When the low-voltage power line is used as a communication line, the channel characteristics have an important impact on the communication quality. In this paper, power distribution networks are divided into three categories. The paper selects a typical power distribution area and uses a rigorous method to test channel attenuation characteristics of the narrowband (50 kHz~500 kHz) carrier. Base on the measurement data, carrier attenuation characteristics are summarized. The measuring method used in the paper and the conclusions of this paper would play a guiding role on the research of the power line carrier communication.

Broadband PLC Network Cross-Layer Simulation in Accordance with the IEEE P1901 Standard

This paper presents the discrete-event simulator of the low-voltage broadband power line communication (BPLC) access network in accordance with the IEEE P1901 standard. The proposed simulator enables the cross-layer simulation of the physical (PHY) and medium access control (MAC) layer. The performance of the digital communication techniques at the physical layer and the characteristics of the shared medium are integrated at the MAC layer through the probability of the bit error. The proposed simulator was applied in order to estimate the throughput in the simple BPLC network. For the selected set of parameters at the MAC and PHY layer in the test network, the simulator recorded average download throughput of 900kbps, registration time of 36ms and packet delivery ratio of for 0.98 between each station and the HE.DOI: http://dx.doi.org/10.5755/j01.eee.19.5.1440

LED 실내조명을 이용한 광무선 원격제어

현재 LED 조명을 이용한 실내 광무선 통신 기술은 상당히 폭 넓게 연구되고 있다. 각 가정에 설치된 전력선 인프라를 조명통신에 접목할 경우 홈 네트워크의 광대역 접속에 대한 요구를 충족시 킬 수 있는 매우 유용한 방법으로 주목받고 있다. 본 연구에서는 LED를 실내조명용과 원격제어를 위한 통신용의 두 가지 조건을 만족시키는 시스템을 설계하고, 광무선제어 성능을 검증하기 위하여 모형차를 제작하여 통신조건을 만족시키는 적절한 조도를 제시하였다. 간이 테스트베드를 이용하여 동작실험을 성공적으로 수행하였다. 가시권에서만 통신할 수 있는 제한에도 불구하고 제안된 기술은 원격제어 시스템이 필요한 전자파 장애지역에서 광무선 통신 기술을 적용하는 새로운 응용영역을 개척할 수 있을 것으로 기대된다.

Research on Remote Meter Reading System Based on PLC Technology

With the deepened transformation of China's power system, the stability and reliability of power utilization have been dramatically improved, but meter reading data acquisition does not keep pace with the times. With the continuous maturity of low-voltage power line communication (PLC), this leads us to see hopes of using PLC technology to realize remote meter reading. In this paper, based on current PLC technology and combining domestic and foreign successful cases, a beneficial exploration and research is conducted from the composition and establishment of software and the design of software and protocol.

Design of Three-Phase Multi-Function Energy Meter Based on Measurement Chip RN8302

According to the development status of the energy meter, we put forward a design of a Three-phase multi-function energy meter based on professional measurement chip RN8302 and High-performance single chip microcomputer MSP430 in this article. It has the characteristics which are low-power consumption, high-precision and electricity anti-theft. It could also real-time measured current, voltage, active power, reactive power, power factor, over-voltage and over-current signal. The design also has the functions of surge prevention, lightning prevention and voltage protection, improving the overall safety and reliability of the system.Use the Low-voltage power line carrier communication, there is no need to build another peripherals,saving the cost of grid investment. The article also gave the overall design scheme and the main hardware principle Schematic.

Towards Modal Integration of Overhead and Underground Low-Voltage and Medium-Voltage Power Line Communication Channels in the Smart Grid Landscape: Model Expansion, Broadband Signal Transmission Characteristics, and Statistical Performance Metrics (Invited Paper)

The established statistical analysis, already used to treat overhead transmission power grid networks, is now implemented to examine the factors influencing modal transmission characteristics and modal statistical performance metrics of overhead and underground low-voltage/broadband over power lines (LV/BPL) and medium-voltage/broadband over power lines (MV/BPL) channels associated with power distribution in smart grid (SG) networks. The novelty of this paper is threefold. First, a refined multidimensional chain scattering matrix (TM2) method suitable for overhead and underground LV/BPL and MV/BPL modal channels is evaluated against other relative theoretical and experimental proven models. Second, applying TM2 method, the end-to-end modal channel attenuation of various LV/BPL and MV/BPL multiconductor transmission line (MTL) configurations is determined. The LV/BPL and MV/BPL transmission channels are investigated with regard to their spectral behavior and their end-to-end modal channel attenuation. It is found that the above features depend drastically on the frequency, the type of power grid, the mode considered, the MTL configuration, the physical properties of the cables used, the end-to-end distance, and the number, the electrical length, and the terminations of the branches encountered along the end-to-end BPL signal propagation. Third, the statistical properties of various overhead and underground LV/BPL and MV/BPL modal channels are investigated revealing the correlation between end-to-end modal channel attenuation and modal root-mean-square delay spread (RMS-DS). Already verified in the case of overhead high-voltage (HV) BPL systems, this fundamental property of several wireline systems is also modally validated against relevant sets of field measurements, numerical results, and recently proposed statistical channel models for various overhead and underground LV/BPL and MV/BPL channels. Based on this common inherent attribute of either transmission or distribution BPL networks, new unified regression trend line is proposed giving a further boost towards BPL system intraoperability. A consequence of this paper is that it aids in gaining a better understanding of the range and coverage that BPL solutions can achieve; a preliminary step toward the system symbiosis between BPL systems and other broadband technologies in an SG environment.

Design and implementation of channel estimation for low-voltage power line communication systems based on OFDM

An optimized channel estimation algorithm based on a time-spread structure in OFDM low-voltage power line communication (PLC) systems is proposed to achieve a lower bit error rate (BER). This paper optimizes the best maximum multi-path delay of the linear minimum mean square error (LMMSE) algorithm in time-domain spread OFDM systems. Simulation results indicate that the BER of the improved method is lower than that of conventional LMMSE algorithm, especially when the signal-to-noise ratio (SNR) is lower than 0 dB. Both the LMMSE algorithm and the proposed algorithm are implemented and fabricated in CSMC 0.18 μm technology. This paper analyzes and compares the hardware complexity and performance of the two algorithms. Measurements indicate that the proposed channel estimator has better performance than the conventional estimator.

Modelling of Remote Area Broadband Technology Over Low Voltage Power Line Channel

Several broadband development initiatives have been proposed in Malaysia in order to Bridging Digital Divide (BDD) through the provisions of the Information and Communication Technology (ICT) services to facilitate wide access to the internet through corporates government and private sector for high level of scio-economy. Nevertheless, there is delay in provide broadband services due to the high cost of deployment in the remote area. Therefore, this paper investigates on Broadband over Power Lines (BPL) technology and Malaysia’s broadband initiatives. BPL transmission technology model of using electrical power lines for data, video and voice transmission is proposed. Furthermore, indoor part of the proposed model is carried out on Matlab/Simulink to explore the validity of power line channel transfer function.

Modeling Research of Background Noise in Low-Voltage Power Line Communication Channel

Background noise interference is one of the most important factors for low-voltage power line communication’s reliability. By analyzing the background noise of low-voltage power line communication’s channel, the background noise’s measuring circuit is set up and the AR model of the measured background noise is established. Both of them are respectively using singular value decomposition and Levinson-Durbin (LD) recursive method to calculate the AR model’s parameters and a comparative analysis of the simulation is made. The results induct: parameters acquired from the methods of singular value decomposition and LD recursive method are feasible, the parameter model from singular value decomposition is relatively complex, but extremely accurate, which is suitable for the off-line calculation and analysis of the low-voltage power line’s background noise; the parameter model from LD recursive method is very simple, but has a greater loss of accuracy, fitting for online quickly generation of the low-voltage power line’s background noise.

The Design of the Ethernet Meter Reading System Based on Broadband Power Line

According to the current national conditions and the intelligent communities’ requirements on the electric energy metering system based on the broadband power line communication (PLC), this paper introduces a design program for achieving the remote meter reading through the broadband PLC technology. The system takes the high-performance single chip microcomputer and the Ethernet controller RTL8019AS as the core, the low-voltage power line as the medium of data communication, and makes the electronic meters access to the Ethernet via the broadband power line, thereby achieving the remote automatic meter reading. The multi-functional low-voltage power line remote meter reading system constituted by this system and the backstage management system together will have broad application prospects. In addition, this paper also makes a preliminary study on the reliability of the meter reading system.

저압용 SPD가 설치된 전력선통신에서 데이터전송 성능 향상

Low-Voltage power lines should equip surge protection devices which protect electronic equipments and human lives against lightning and abnormal voltages. Data transmission capacity of the power line is determined by frequency characteristics of the surge protective devices. To analyze the effects of surge protective devices on the data transmission performance, various combinations of installation methods are tested which include ZnO varistor elements that is compatible with classⅠ, classⅡ and class Ⅲ. The result claims that ZnO varistor for class Ⅲ is found to be one of the main factors that deteriorates the transmission performance. To overcome this problem a serial connection methed between Gap type SPD and ZnO varistor is proposed. With the proposed scheme, laboratory experimental results show that the data transmission performance can be improved up to 91.9[%] with proper SPD combination.

The Double-Signals’ Switch of Car Steering and its Management System’s Design

The management system of the double switching signals’ design is to achieve the persistent light warning effect by switching to the other main signal automatically when the car’s turning signal is broken. This self-bringing manage system will automatically record the specific location of the broken signal light, and will notice the conservator or the maintenance worker to keep in repair the signal light. Thus, this way can improve managerial effectiveness and shorten examining time. This design adopts single chip or logic control chip to realize automatic switch; and transfers signals between turning signals and main control system according to low voltage power line transmission technology or wireless transmission technology. Based on this, the system will keep working constantly, and facilitate conservators to find stoppages and solve them efficiently.

A Noise Eliminating Method of DCSK System Based on Multi-Layered Noise Control Materials

This paper proposes a new chaotic communication scheme which is developed from Differential Chaos Shift Keying (DCSK), named reversed-phase overlay DCSK. Different from DCSK, at the receiver of the improved scheme the first and the second half-symbol signals within a code period are reversed-phase overlapped before the correlation operation. Both the theoretical analysis and the simulation results show that the proposed scheme can effectively suppress the noise and improve the BER performance of DCSK if the channel noise in the first half of a code period and the second is positively correlated. The proposed scheme can be applied to the communication systems suffering with colored noise, such as Low-voltage Power Line Communication(L-PLC) system

FFU Motors Remote Monitoring System Based on Power Line Communication and GPRS

In view of the advantage of low voltage power line carrier technique and general packet radio service(GPRS), a solution of fan filter unit(FFU) motor remote mointoring system based on GPRS and low voltage power line communication is introduced. This system combines a framework of low voltage power line communication and GPRS network with host computer monitoring center, which changes the traditional FFU motor control mode, and realize FFU motor remote real-time on-line automatic monitoring.The system implementation methods were described in detail, and the hardware and sofware design were given.The test and practice showed that the proposed has higher efficient and stronger anti-interference capability, which met the requirements of networkization and intelligentization, and a better way for the FFU motor control. The designed system has good application value.

Reduction of power losses with smart grids fueled with renewable sources and applying EV batteries

Abstract This paper describes a low-voltage grid composed of small, domestic power plants fueled by clean and renewable energy sources and augmented with electric vehicle batteries as power storage devices. We propose that this grid could utilize a complex multifunctional control unit capable of optimizing the working point and charging current of the system, while also implementing active power factor correction, lowering extant harmonic distortion and controlling the voltage level in the low-voltage power lines. The complex controller structure proposed in this paper contains the following novel components: an upper harmonic controller which (together with the connection voltage controller) minimizes the amplitudes of the 3rd, 5th, 7th, 9th, and 11th high order components in the output voltage; and a connection voltage controller which controls the energy flow between the low-voltage network, its renewable energy sources and the electrical vehicle batteries. Unlike other similar approaches, the harmonic controller proposed in this paper does not rely on a measured current signal but rather optimizes the voltage shape, the latter of which depends on the nonlinear distortion of the whole low-voltage transformer area and determines additional power losses. We analyzed the proposed controller via simulations in a Matlab environment and as a result, achieved substantial improvements to the output voltage, current waveform and energy flow of the system’s low-voltage conditions. Our calculations show that the implementation of substantial reductions in CO2 emissions could be achieved for an average household. The robustness of the method against nonlinear loads and fluctuations in overloads and overproductions was also tested.