Power distribution facilities all over the world have been committed towards making the grids smarter in order to reduce the risks of grid failures and provide an affordable, reliable, and sustainable supply of electricity to the end consumers. The smart grid concept involves incorporation of monitoring, analysis and control functions into the existing power distribution infrastructure. One of the foremost steps in realizing the smart grid concept is the integration of information and communication technologies with power system engineering. Various communication technologies are available, out of which Powerline Communication (PLC) has been found to be most suitable owing to its least intensiveness on additional infrastructure. Existing methods use PLC as a separate communication physical layer to establish com- munication between components in a micro/sub-micro grid. However, these methods poses the problems of a separate physical layer requirement to establish communication between inverters, attenuation of the information signal by the EMI filters present in various loads and equipments connected to the micro grid, requirement of signal repeaters at regular distance intervals and requirement of a separate server for monitoring and control. In order to simultaneously utilize the incorporation of front end inverters into the grid and achieve inter-inverter communication, a PLC method for the grid connected inverters based on a harmonic injection into the grid current is proposed in this thesis. The harmonic injection is accomplished by considering the grid current as a composite vector with components rotating at different speeds. The lower harmonic spectrum space can be chosen to avoid the attenuation problems associated with the EMI filters. In the proposed method, as the choice of the harmonic space is flexible, it is possible to even adopt a dynamically changing harmonic space to optimize THD. The advantage of the method is that it simultaneously achieves communication along with grid interfacing of DGs without any requirement of extra hardware. Also, since the principle of information exchange amongst inverters is the same as that of the power transfer, there is no added complexity involved in the inverter control system due to the proposed PLC method. The principle of the Composite Space Vector on which the proposed PLC method is based upon has been explained in detail along with the frame transformation equations. The control scheme to achieve the power transfer and the information exchange for the grid connected inverters is explained. The design procedure for various circuit elements and the control loop parameters has been explained. The thesis also discusses the various factors affecting the choice of the modulating signal and the speed of communication achievable in the proposed PLC method. For both the three phase and single phase systems, simulation results have been presented for the proposed PLC method under different grid conditions and different harmonics as the modulating signals. The simulations have been performed using the MATLAB SIMULINK SimPowerSystems toolbox. The simulation results have been experimentally verified through a laboratory prototype. The laboratory prototype consists of individual IGBT based inverters controlled through the Texas Instruments TMS320F2812 DSP based digital controller.

Future smart grid systems will intelligently monitor and control energy flows in order to improve the efficiency and reliability of power delivery. This monitoring and control requires low-power, low-cost and highly reliable two-way communications between customers and utilities. To enable these two-way communication links, powerline communication (PLC) systems are attractive because they can be deployed over existing outdoor and indoor power lines. Power lines, however, have traditionally been designed for one-directional power delivery and remain hostile environments for communication signal propagation. In particular, non-Gaussian noise that is dominated by asynchronous impulsive noise and periodic impulsive noise, is one of the primary factors that limit the communication performance of PLC systems. For my PhD dissertation, I propose transmitter and receiver methods to mitigate the impact of asynchronous impulsive noise and periodic impulsive noise, respectively, on PLC systems. The methods exploit sparsity and/or cyclostationarity of the noise in both time and frequency domains, and require no or minor training overhead prior to data transmission. Compared to conventional PLC systems, the proposed transceivers achieve dramatic improvement (up to 1000x) in coded bit error rates in simulations, while maintaining similar throughput. / text

No description available.

Zugl.: Karlsruhe, Universiẗat, Diss., 2007.

Zugl.: Dresden, Techn. Univ., Diss., 2008

Zugl.: Erlangen, Nürnberg, Univ., Diss., 2009

In many outage management systems, customer trouble calls have been used as the primary source of outages for distribution level outages. However the information from the trouble calls is not completely reliable as they lead to problems like okay-on-arrival reports, over escalation and extended outage times for the customers. But with the recent developments in communication and information technologies, utilities started to adopt Automated Meter Reading systems for their operational needs. In this thesis, an algorithm is developed and implemented that makes efficient use information available from the customers and powerline communication based AMR systems for outages. The work has taken advantage of the polling feature of powerline based AMR systems to identify the scope of the outage. The polling procedure uses the on demand read feature of the AMR systems that allows the utility to communicate directly with the customers. The meters in the neighborhood of the trouble calls are polled to identify the affected customers and the outages are located by back tracking to common point. In the first part of the algorithm, the distribution system is modeled as a tree and the meters are strategically polled based on the customers reporting the outages. The outage areas are identified and escalated to find the actual outage location. The crew can be directed to the outage scene to fix the cause of the outage. The algorithm discusses the rules to identify single outages, single customer outages and multiple outages. The algorithm was tested on different test systems representing distribution systems of various sizes. The algorithm is tested for different outage scenarios for all the test cases.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-03-02T12:13:28Z No. of bitstreams: 1 antonioangelomissiaggiapicrone.pdf: 1988788 bytes, checksum: 6b0bc2b5525993261c14440b4ad8a007 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-06T19:35:07Z (GMT) No. of bitstreams: 1 antonioangelomissiaggiapicrone.pdf: 1988788 bytes, checksum: 6b0bc2b5525993261c14440b4ad8a007 (MD5) / Made available in DSpace on 2017-03-06T19:35:07Z (GMT). No. of bitstreams: 1 antonioangelomissiaggiapicrone.pdf: 1988788 bytes, checksum: 6b0bc2b5525993261c14440b4ad8a007 (MD5) Previous issue date: 2009-08-31 / Nesta dissertação é discutido e analisado o desempenho de técnicas de estimação de canais baseada em sinais piloto para modulação OFDM (Orthogonal Frequency Division Multiplexing), aplicada a transmissão de dados através de canais PLC (Power Line Communications). Os canais PLC são modelados como linear e invariante no tempo (LIT), linear e variante no tempo (LVT) e linear e ciclicamente variante no tempo (LCVT) e um modelo de ruído aditivo impulsivo gaussiano (AIGN) é considerado. São mostrados os resultados de análises de desempenhos obtidos com os estimadores de canal adaptativo e n˜ao adaptativo associados com equalizadores de canal e técnicas estratégicas de alocação de sinais piloto. Os resultados obtidos, com base no desempenho das simulações, apontam direções interessantes para melhorar as técnicas de estimação de canais baseadas em sinais piloto quando o canal PLC é LIT, LVT ou LCVT e corrompidos por ruído AIGN. / In this dissertation is discussed and analyzed the performance of pilot-assisted channel estimation techniques for OFDM (Orthogonal Frequency Division Multiplexing) modulation that is applied to data transmission through PLC (power line communications) channels. The PLC channels are modeled as linear and time-invariant (LIT), linear and time variant (LTV), and linear and cyclic time-variant (LCTV) ones when the additive impulsive gaussian noise (AIGN) is considered. Performance analysis obtained with adaptive and nonadaptive channel estimation techniques together with channel equalization and pilot signal allocation ones are provided. The results based upon performance simulation offer interesting directions to improve pilot-assisted channel estimation techniques when the PLC channel are LIT, LTV or LCTV corrupted by AIGN.

Opportunistic Routing (OR) can be used as an alternative to the legacy routing (LR) protocols in networks with a broadcast lossy channel and possibility of overhearing the signal. The power line medium creates such an environment. OR can better exploit the channel than LR because it allows the cooperation of all nodes that receive any data. With LR, only a chain of nodes is selected for communication. Other nodes drop the received information. We investigate OR for the one-source one-destination scenario with one traffic flow. First, we evaluate the upper bound on the achievable data rate and advocate the decentralized algorithm for its calculation. This knowledge is used in the design of Basic Routing Rules (BRR). They use the link quality metric that equals the upper bound on the achievable data rate between the given node and the destination. We call it the node priority. It considers the possibility of multi-path communication and the packet loss correlation. BRR allows achieving the optimal data rate pertaining certain theoretical assumptions. The Extended BRR (BRR-E) are free of them. The major difference between BRR and BRR-E lies in the usage of Network Coding (NC) for prognosis of the feedback. In this way, the protocol overhead can be severely reduced. We also study Automatic Repeat-reQuest (ARQ) mechanism that is applicable with OR. It differs to ARQ with LR in that each sender has several sinks and none of the sinks except destination require the full recovery of the original message. Using BRR-E, ARQ and other services like network initialization and link state control, we design the Advanced Network Coding based Opportunistic Routing protocol (ANChOR). With the analytic and simulation results we demonstrate the near optimum performance of ANChOR. For the triangular topology, the achievable data rate is just 2% away from the theoretical maximum and it is up to 90% higher than it is possible to achieve with LR. Using the G.hn standard, we also show the full protocol stack simulation results (including IP/UDP and realistic channel model). In this simulation we revealed that the gain of OR to LR can be even more increased by reducing the head-of-the-line problem in ARQ. Even considering the ANChOR overhead through additional headers and feedbacks, it outperforms the original G.hn setup in data rate up to 40% and in latency up to 60%.:1 Introduction 2 1.1 Intra-flow Network Coding 6 1.2 Random Linear Network Coding (RLNC) 7 2 Performance Limits of Routing Protocols in PowerLine Communications (PLC) 13 2.1 System model 14 2.2 Channel model 14 2.3 Upper bound on the achievable data rate 16 2.4 Achieving the upper bound data rate 17 2.5 Potential gain of Opportunistic Routing Protocol (ORP) over Common Single-path Routing Protocol (CSPR) 19 2.6 Evaluation of ORP potential 19 3 Opportunistic Routing: Realizations and Challenges 24 3.1 Vertex priority and cooperation group 26 3.2 Transmission policy in idealized network 34 3.2.1 Basic Routing Rules (BRR) 36 3.3 Transmission policy in real network 40 3.3.1 Purpose of Network Coding (NC) in ORP 41 3.3.2 Extended Basic Routing Rules (BRR) (BRR-E) 43 3.4 Automatic ReQuest reply (ARQ) 50 3.4.1 Retransmission request message contents 51 3.4.2 Retransmission Request (RR) origination and forwarding 66 3.4.3 Retransmission response 67 3.5 Congestion control 68 3.5.1 Congestion control in our work 70 3.6 Network initialization 74 3.7 Formation of the cooperation groups (coalitions) 76 3.8 Advanced Network Coding based Opportunistic Routing protocol (ANChOR) header 77 3.9 Communication of protocol information 77 3.10 ANChOR simulation . .79 3.10.1 ANChOR information in real time .80 3.10.2 Selection of the coding rate 87 3.10.3 Routing Protocol Information (RPI) broadcasting frequency 89 3.10.4 RR contents 91 3.10.5 Selection of RR forwarder 92 3.10.6 ANChOR stability 92 3.11 Summary 95 4 ANChOR in the Gigabit Home Network (G.hn) Protocol 97 4.1 Compatibility with the PLC protocol stack 99 4.2 Channel and noise model 101 4.2.1 In-home scenario 102 4.2.2 Access network scenario 102 4.3 Physical layer (PHY) layer implementation 102 4.3.1 Bit Allocation Algorithm (BAA) 103 4.4 Multiple Access Control layer (MAC) layer 109 4.5 Logical Link Control layer (LLC) layer 111 4.5.1 Reference Automatic Repeat reQuest (ARQ) 111 4.5.2 Hybrid Automatic Repeat reQuest (HARQ) in ANChOR 114 4.5.3 Modeling Protocol Data Unit (PDU) erasures on LLC 116 4.6 Summary 117 5 Study of G.hn with ANChOR 119 5.1 ARQ analysis 119 5.2 Medium and PHY requirements for “good” cooperation 125 5.3 Access network scenario 128 5.4 In-home scenario 135 5.4.1 Modeling packet erasures 136 5.4.2 Linear Dependence Ratio (LDR) 139 5.4.3 Worst case scenario 143 5.4.4 Analysis of in-home topologies 145 6 Conclusions . . . . . . . . . . . . . . . 154 A Proof of the neccessity of the exclusion rule 160 B Gain of ORPs to CSRPs 163 C Broadcasting rule 165 D Proof of optimality of BRR for triangular topology 167 E Reducing the retransmission probability 168 F Calculation of Expected Average number of transmissions (EAX) for topologies with bi-directional links 170 G Feedback overhead of full coding matrices 174 H Block diagram of G.hn physical layer in ns-3 model 175 I PER to BER mapping 177

The subject of graduation thesis is a design of line analyser according to standard EN61000-4-30 class A. The analyser is determine to be used for quality control of supplied electric power which is, during electric power transmission, affected by several disturbances. Power line analyser should measure single-phase and three-phase network parameters in LV and HV systems. Measured parameters can be shown on the full colour TFT display, stored in the device memory or sent to other devices such as PC. For communication between the device and PC the USB, Ethernet or RS485 interface are used.